Revert "Move tests out of package to top level directory (#1232)" (#1242)

This reverts commit b578d2febfd35f80fcfa1ce1bdf18d44d21b1581.

17 files changed, 11053 insertions, 0 deletions

diff --git a/psutil/tests/README.rst b/psutil/tests/README.rst
new file mode 100644
index 00000000..515abf77
--- /dev/null
+++ b/psutil/tests/README.rst
@@ -0,0 +1,23 @@
+Instructions for running tests
+==============================
+
+* There are two ways of running tests. As a "user", if psutil is already
+  installed and you just want to test it works::
+
+    python -m psutil.tests --install-deps  # install test deps
+    python -m psutil.tests
+
+  As a "developer", if you have a copy of the source code and you whish to hack
+  on psutil::
+
+    make setup-dev-env  # install test deps (+ other things)
+    make test
+
+* To run tests on all supported Python versions install tox
+  (``pip install tox``) then run ``tox`` from within psutil root directory.
+
+* Every time a commit is pushed tests are automatically run on Travis
+  (Linux, OSX) and appveyor (Windows):
+
+  * Travis builds: https://travis-ci.org/giampaolo/psutil
+  * AppVeyor builds: https://ci.appveyor.com/project/giampaolo/psutil
diff --git a/psutil/tests/__init__.py b/psutil/tests/__init__.py
new file mode 100644
index 00000000..499240fb
--- /dev/null
+++ b/psutil/tests/__init__.py
@@ -0,0 +1,1198 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Test utilities.
+"""
+
+from __future__ import print_function
+
+import atexit
+import contextlib
+import ctypes
+import errno
+import functools
+import os
+import random
+import re
+import select
+import shutil
+import socket
+import stat
+import subprocess
+import sys
+import tempfile
+import textwrap
+import threading
+import time
+import traceback
+import warnings
+from socket import AF_INET
+from socket import AF_INET6
+from socket import SOCK_DGRAM
+from socket import SOCK_STREAM
+
+import psutil
+from psutil import OSX
+from psutil import POSIX
+from psutil import SUNOS
+from psutil import WINDOWS
+from psutil._common import supports_ipv6
+from psutil._compat import PY3
+from psutil._compat import u
+from psutil._compat import unicode
+from psutil._compat import which
+
+if sys.version_info < (2, 7):
+    import unittest2 as unittest  # requires "pip install unittest2"
+else:
+    import unittest
+
+try:
+    from unittest import mock  # py3
+except ImportError:
+    import mock  # NOQA - requires "pip install mock"
+
+if sys.version_info >= (3, 4):
+    import enum
+else:
+    enum = None
+
+
+__all__ = [
+    # constants
+    'APPVEYOR', 'DEVNULL', 'GLOBAL_TIMEOUT', 'MEMORY_TOLERANCE', 'NO_RETRIES',
+    'PYPY', 'PYTHON_EXE', 'ROOT_DIR', 'SCRIPTS_DIR', 'TESTFILE_PREFIX',
+    'TESTFN', 'TESTFN_UNICODE', 'TOX', 'TRAVIS', 'VALID_PROC_STATUSES',
+    'VERBOSITY',
+    "HAS_CPU_AFFINITY", "HAS_CPU_FREQ", "HAS_ENVIRON", "HAS_PROC_IO_COUNTERS",
+    "HAS_IONICE", "HAS_MEMORY_MAPS", "HAS_PROC_CPU_NUM", "HAS_RLIMIT",
+    "HAS_SENSORS_BATTERY", "HAS_BATTERY", "HAS_SENSORS_FANS",
+    "HAS_SENSORS_TEMPERATURES", "HAS_MEMORY_FULL_INFO",
+    # subprocesses
+    'pyrun', 'reap_children', 'get_test_subprocess', 'create_zombie_proc',
+    'create_proc_children_pair',
+    # threads
+    'ThreadTask'
+    # test utils
+    'unittest', 'skip_on_access_denied', 'skip_on_not_implemented',
+    'retry_before_failing', 'run_test_module_by_name', 'get_suite',
+    'run_suite',
+    # install utils
+    'install_pip', 'install_test_deps',
+    # fs utils
+    'chdir', 'safe_rmpath', 'create_exe', 'decode_path', 'encode_path',
+    'unique_filename',
+    # os
+    'get_winver', 'get_kernel_version',
+    # sync primitives
+    'call_until', 'wait_for_pid', 'wait_for_file',
+    # network
+    'check_connection_ntuple', 'check_net_address',
+    'get_free_port', 'unix_socket_path', 'bind_socket', 'bind_unix_socket',
+    'tcp_socketpair', 'unix_socketpair', 'create_sockets',
+    # compat
+    'reload_module', 'import_module_by_path',
+    # others
+    'warn', 'copyload_shared_lib', 'is_namedtuple',
+]
+
+
+# ===================================================================
+# --- constants
+# ===================================================================
+
+# --- platforms
+
+TOX = os.getenv('TOX') or '' in ('1', 'true')
+PYPY = '__pypy__' in sys.builtin_module_names
+WIN_VISTA = (6, 0, 0) if WINDOWS else None
+# whether we're running this test suite on Travis (https://travis-ci.org/)
+TRAVIS = bool(os.environ.get('TRAVIS'))
+# whether we're running this test suite on Appveyor for Windows
+# (http://www.appveyor.com/)
+APPVEYOR = bool(os.environ.get('APPVEYOR'))
+
+# --- configurable defaults
+
+# how many times retry_before_failing() decorator will retry
+NO_RETRIES = 10
+# bytes tolerance for system-wide memory related tests
+MEMORY_TOLERANCE = 500 * 1024  # 500KB
+# the timeout used in functions which have to wait
+GLOBAL_TIMEOUT = 3
+# test output verbosity
+VERBOSITY = 1 if os.getenv('SILENT') or TOX else 2
+# be more tolerant if we're on travis / appveyor in order to avoid
+# false positives
+if TRAVIS or APPVEYOR:
+    NO_RETRIES *= 3
+    GLOBAL_TIMEOUT *= 3
+
+# --- files
+
+TESTFILE_PREFIX = '$testfn'
+TESTFN = os.path.join(os.path.realpath(os.getcwd()), TESTFILE_PREFIX)
+_TESTFN = TESTFN + '-internal'
+TESTFN_UNICODE = TESTFN + u("-ƒőő")
+ASCII_FS = sys.getfilesystemencoding().lower() in ('ascii', 'us-ascii')
+
+# --- paths
+
+ROOT_DIR = os.path.abspath(os.path.join(os.path.dirname(__file__), '..', '..'))
+SCRIPTS_DIR = os.path.join(ROOT_DIR, 'scripts')
+HERE = os.path.abspath(os.path.dirname(__file__))
+
+# --- support
+
+HAS_CPU_AFFINITY = hasattr(psutil.Process, "cpu_affinity")
+HAS_CPU_FREQ = hasattr(psutil, "cpu_freq")
+HAS_CONNECTIONS_UNIX = POSIX and not SUNOS
+HAS_ENVIRON = hasattr(psutil.Process, "environ")
+HAS_PROC_IO_COUNTERS = hasattr(psutil.Process, "io_counters")
+HAS_IONICE = hasattr(psutil.Process, "ionice")
+HAS_MEMORY_FULL_INFO = 'uss' in psutil.Process().memory_full_info()._fields
+HAS_MEMORY_MAPS = hasattr(psutil.Process, "memory_maps")
+HAS_PROC_CPU_NUM = hasattr(psutil.Process, "cpu_num")
+HAS_RLIMIT = hasattr(psutil.Process, "rlimit")
+HAS_THREADS = hasattr(psutil.Process, "threads")
+HAS_SENSORS_BATTERY = hasattr(psutil, "sensors_battery")
+HAS_BATTERY = HAS_SENSORS_BATTERY and psutil.sensors_battery()
+HAS_SENSORS_FANS = hasattr(psutil, "sensors_fans")
+HAS_SENSORS_TEMPERATURES = hasattr(psutil, "sensors_temperatures")
+
+# --- misc
+
+
+def _get_py_exe():
+    def attempt(exe):
+        try:
+            subprocess.check_call(
+                [exe, "-V"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        except Exception:
+            return None
+        else:
+            return exe
+
+    if OSX:
+        exe = \
+            attempt(sys.executable) or \
+            attempt(os.path.realpath(sys.executable)) or \
+            attempt(which("python%s.%s" % sys.version_info[:2])) or \
+            attempt(psutil.Process().exe())
+        if not exe:
+            raise ValueError("can't find python exe real abspath")
+        return exe
+    else:
+        exe = os.path.realpath(sys.executable)
+        assert os.path.exists(exe), exe
+        return exe
+
+
+PYTHON_EXE = _get_py_exe()
+DEVNULL = open(os.devnull, 'r+')
+VALID_PROC_STATUSES = [getattr(psutil, x) for x in dir(psutil)
+                       if x.startswith('STATUS_')]
+AF_UNIX = getattr(socket, "AF_UNIX", object())
+SOCK_SEQPACKET = getattr(socket, "SOCK_SEQPACKET", object())
+
+_subprocesses_started = set()
+_pids_started = set()
+_testfiles_created = set()
+
+
+@atexit.register
+def _cleanup_files():
+    DEVNULL.close()
+    for name in os.listdir(u('.')):
+        if isinstance(name, unicode):
+            prefix = u(TESTFILE_PREFIX)
+        else:
+            prefix = TESTFILE_PREFIX
+        if name.startswith(prefix):
+            try:
+                safe_rmpath(name)
+            except Exception:
+                traceback.print_exc()
+    for path in _testfiles_created:
+        try:
+            safe_rmpath(path)
+        except Exception:
+            traceback.print_exc()
+
+
+# this is executed first
+@atexit.register
+def _cleanup_procs():
+    reap_children(recursive=True)
+
+
+# ===================================================================
+# --- threads
+# ===================================================================
+
+
+class ThreadTask(threading.Thread):
+    """A thread task which does nothing expect staying alive."""
+
+    def __init__(self):
+        threading.Thread.__init__(self)
+        self._running = False
+        self._interval = 0.001
+        self._flag = threading.Event()
+
+    def __repr__(self):
+        name = self.__class__.__name__
+        return '<%s running=%s at %#x>' % (name, self._running, id(self))
+
+    def __enter__(self):
+        self.start()
+        return self
+
+    def __exit__(self, *args, **kwargs):
+        self.stop()
+
+    def start(self):
+        """Start thread and keep it running until an explicit
+        stop() request. Polls for shutdown every 'timeout' seconds.
+        """
+        if self._running:
+            raise ValueError("already started")
+        threading.Thread.start(self)
+        self._flag.wait()
+
+    def run(self):
+        self._running = True
+        self._flag.set()
+        while self._running:
+            time.sleep(self._interval)
+
+    def stop(self):
+        """Stop thread execution and and waits until it is stopped."""
+        if not self._running:
+            raise ValueError("already stopped")
+        self._running = False
+        self.join()
+
+
+# ===================================================================
+# --- subprocesses
+# ===================================================================
+
+
+def _reap_children_on_err(fun):
+    @functools.wraps(fun)
+    def wrapper(*args, **kwargs):
+        try:
+            return fun(*args, **kwargs)
+        except Exception:
+            reap_children()
+            raise
+    return wrapper
+
+
+@_reap_children_on_err
+def get_test_subprocess(cmd=None, **kwds):
+    """Creates a python subprocess which does nothing for 60 secs and
+    return it as subprocess.Popen instance.
+    If "cmd" is specified that is used instead of python.
+    By default stdin and stdout are redirected to /dev/null.
+    It also attemps to make sure the process is in a reasonably
+    initialized state.
+    The process is registered for cleanup on reap_children().
+    """
+    kwds.setdefault("stdin", DEVNULL)
+    kwds.setdefault("stdout", DEVNULL)
+    kwds.setdefault("cwd", os.getcwd())
+    kwds.setdefault("env", os.environ)
+    if WINDOWS:
+        # Prevents the subprocess to open error dialogs.
+        kwds.setdefault("creationflags", 0x8000000)  # CREATE_NO_WINDOW
+    if cmd is None:
+        safe_rmpath(_TESTFN)
+        pyline = "from time import sleep;" \
+                 "open(r'%s', 'w').close();" \
+                 "sleep(60);" % _TESTFN
+        cmd = [PYTHON_EXE, "-c", pyline]
+        sproc = subprocess.Popen(cmd, **kwds)
+        _subprocesses_started.add(sproc)
+        wait_for_file(_TESTFN, delete=True, empty=True)
+    else:
+        sproc = subprocess.Popen(cmd, **kwds)
+        _subprocesses_started.add(sproc)
+        wait_for_pid(sproc.pid)
+    return sproc
+
+
+@_reap_children_on_err
+def create_proc_children_pair():
+    """Create a subprocess which creates another one as in:
+    A (us) -> B (child) -> C (grandchild).
+    Return a (child, grandchild) tuple.
+    The 2 processes are fully initialized and will live for 60 secs
+    and are registered for cleanup on reap_children().
+    """
+    _TESTFN2 = os.path.basename(_TESTFN) + '2'  # need to be relative
+    s = textwrap.dedent("""\
+        import subprocess, os, sys, time
+        s = "import os, time;"
+        s += "f = open('%s', 'w');"
+        s += "f.write(str(os.getpid()));"
+        s += "f.close();"
+        s += "time.sleep(60);"
+        subprocess.Popen(['%s', '-c', s])
+        time.sleep(60)
+        """ % (_TESTFN2, PYTHON_EXE))
+    # On Windows if we create a subprocess with CREATE_NO_WINDOW flag
+    # set (which is the default) a "conhost.exe" extra process will be
+    # spawned as a child. We don't want that.
+    if WINDOWS:
+        subp = pyrun(s, creationflags=0)
+    else:
+        subp = pyrun(s)
+    child1 = psutil.Process(subp.pid)
+    data = wait_for_file(_TESTFN2, delete=False, empty=False)
+    os.remove(_TESTFN2)
+    child2_pid = int(data)
+    _pids_started.add(child2_pid)
+    child2 = psutil.Process(child2_pid)
+    return (child1, child2)
+
+
+def create_zombie_proc():
+    """Create a zombie process and return its PID."""
+    assert psutil.POSIX
+    unix_file = tempfile.mktemp(prefix=TESTFILE_PREFIX) if OSX else TESTFN
+    src = textwrap.dedent("""\
+        import os, sys, time, socket, contextlib
+        child_pid = os.fork()
+        if child_pid > 0:
+            time.sleep(3000)
+        else:
+            # this is the zombie process
+            s = socket.socket(socket.AF_UNIX)
+            with contextlib.closing(s):
+                s.connect('%s')
+                if sys.version_info < (3, ):
+                    pid = str(os.getpid())
+                else:
+                    pid = bytes(str(os.getpid()), 'ascii')
+                s.sendall(pid)
+        """ % unix_file)
+    with contextlib.closing(socket.socket(socket.AF_UNIX)) as sock:
+        sock.settimeout(GLOBAL_TIMEOUT)
+        sock.bind(unix_file)
+        sock.listen(1)
+        pyrun(src)
+        conn, _ = sock.accept()
+        try:
+            select.select([conn.fileno()], [], [], GLOBAL_TIMEOUT)
+            zpid = int(conn.recv(1024))
+            _pids_started.add(zpid)
+            zproc = psutil.Process(zpid)
+            call_until(lambda: zproc.status(), "ret == psutil.STATUS_ZOMBIE")
+            return zpid
+        finally:
+            conn.close()
+
+
+@_reap_children_on_err
+def pyrun(src, **kwds):
+    """Run python 'src' code string in a separate interpreter.
+    Returns a subprocess.Popen instance.
+    """
+    kwds.setdefault("stdout", None)
+    kwds.setdefault("stderr", None)
+    with tempfile.NamedTemporaryFile(
+            prefix=TESTFILE_PREFIX, mode="wt", delete=False) as f:
+        _testfiles_created.add(f.name)
+        f.write(src)
+        f.flush()
+        subp = get_test_subprocess([PYTHON_EXE, f.name], **kwds)
+        wait_for_pid(subp.pid)
+    return subp
+
+
+@_reap_children_on_err
+def sh(cmd, **kwds):
+    """run cmd in a subprocess and return its output.
+    raises RuntimeError on error.
+    """
+    shell = True if isinstance(cmd, (str, unicode)) else False
+    # Prevents subprocess to open error dialogs in case of error.
+    flags = 0x8000000 if WINDOWS and shell else 0
+    kwds.setdefault("shell", shell)
+    kwds.setdefault("stdout", subprocess.PIPE)
+    kwds.setdefault("stderr", subprocess.PIPE)
+    kwds.setdefault("universal_newlines", True)
+    kwds.setdefault("creationflags", flags)
+    p = subprocess.Popen(cmd, **kwds)
+    _subprocesses_started.add(p)
+    stdout, stderr = p.communicate()
+    if p.returncode != 0:
+        raise RuntimeError(stderr)
+    if stderr:
+        warn(stderr)
+    if stdout.endswith('\n'):
+        stdout = stdout[:-1]
+    return stdout
+
+
+def reap_children(recursive=False):
+    """Terminate and wait() any subprocess started by this test suite
+    and ensure that no zombies stick around to hog resources and
+    create problems  when looking for refleaks.
+
+    If resursive is True it also tries to terminate and wait()
+    all grandchildren started by this process.
+    """
+    # This is here to make sure wait_procs() behaves properly and
+    # investigate:
+    # https://ci.appveyor.com/project/giampaolo/psutil/build/job/
+    #     jiq2cgd6stsbtn60
+    def assert_gone(pid):
+        assert not psutil.pid_exists(pid), pid
+        assert pid not in psutil.pids(), pid
+        try:
+            p = psutil.Process(pid)
+            assert not p.is_running(), pid
+        except psutil.NoSuchProcess:
+            pass
+        else:
+            assert 0, "pid %s is not gone" % pid
+
+    # Get the children here, before terminating the children sub
+    # processes as we don't want to lose the intermediate reference
+    # in case of grandchildren.
+    if recursive:
+        children = set(psutil.Process().children(recursive=True))
+    else:
+        children = set()
+
+    # Terminate subprocess.Popen instances "cleanly" by closing their
+    # fds and wiat()ing for them in order to avoid zombies.
+    while _subprocesses_started:
+        subp = _subprocesses_started.pop()
+        _pids_started.add(subp.pid)
+        try:
+            subp.terminate()
+        except OSError as err:
+            if err.errno != errno.ESRCH:
+                raise
+        if subp.stdout:
+            subp.stdout.close()
+        if subp.stderr:
+            subp.stderr.close()
+        try:
+            # Flushing a BufferedWriter may raise an error.
+            if subp.stdin:
+                subp.stdin.close()
+        finally:
+            # Wait for the process to terminate, to avoid zombies.
+            try:
+                subp.wait()
+            except OSError as err:
+                if err.errno != errno.ECHILD:
+                    raise
+
+    # Terminate started pids.
+    while _pids_started:
+        pid = _pids_started.pop()
+        try:
+            p = psutil.Process(pid)
+        except psutil.NoSuchProcess:
+            assert_gone(pid)
+        else:
+            children.add(p)
+
+    # Terminate children.
+    if children:
+        for p in children:
+            try:
+                p.terminate()
+            except psutil.NoSuchProcess:
+                pass
+        gone, alive = psutil.wait_procs(children, timeout=GLOBAL_TIMEOUT)
+        for p in alive:
+            warn("couldn't terminate process %r; attempting kill()" % p)
+            try:
+                p.kill()
+            except psutil.NoSuchProcess:
+                pass
+        gone, alive = psutil.wait_procs(alive, timeout=GLOBAL_TIMEOUT)
+        if alive:
+            for p in alive:
+                warn("process %r survived kill()" % p)
+
+        for p in children:
+            assert_gone(p.pid)
+
+
+# ===================================================================
+# --- OS
+# ===================================================================
+
+
+def get_kernel_version():
+    """Return a tuple such as (2, 6, 36)."""
+    if not POSIX:
+        raise NotImplementedError("not POSIX")
+    s = ""
+    uname = os.uname()[2]
+    for c in uname:
+        if c.isdigit() or c == '.':
+            s += c
+        else:
+            break
+    if not s:
+        raise ValueError("can't parse %r" % uname)
+    minor = 0
+    micro = 0
+    nums = s.split('.')
+    major = int(nums[0])
+    if len(nums) >= 2:
+        minor = int(nums[1])
+    if len(nums) >= 3:
+        micro = int(nums[2])
+    return (major, minor, micro)
+
+
+def get_winver():
+    if not WINDOWS:
+        raise NotImplementedError("not WINDOWS")
+    wv = sys.getwindowsversion()
+    if hasattr(wv, 'service_pack_major'):  # python >= 2.7
+        sp = wv.service_pack_major or 0
+    else:
+        r = re.search(r"\s\d$", wv[4])
+        if r:
+            sp = int(r.group(0))
+        else:
+            sp = 0
+    return (wv[0], wv[1], sp)
+
+
+# ===================================================================
+# --- sync primitives
+# ===================================================================
+
+
+class retry(object):
+    """A retry decorator."""
+
+    def __init__(self,
+                 exception=Exception,
+                 timeout=None,
+                 retries=None,
+                 interval=0.001,
+                 logfun=lambda s: print(s, file=sys.stderr),
+                 ):
+        if timeout and retries:
+            raise ValueError("timeout and retries args are mutually exclusive")
+        self.exception = exception
+        self.timeout = timeout
+        self.retries = retries
+        self.interval = interval
+        self.logfun = logfun
+
+    def __iter__(self):
+        if self.timeout:
+            stop_at = time.time() + self.timeout
+            while time.time() < stop_at:
+                yield
+        elif self.retries:
+            for _ in range(self.retries):
+                yield
+        else:
+            while True:
+                yield
+
+    def sleep(self):
+        if self.interval is not None:
+            time.sleep(self.interval)
+
+    def __call__(self, fun):
+        @functools.wraps(fun)
+        def wrapper(*args, **kwargs):
+            exc = None
+            for _ in self:
+                try:
+                    return fun(*args, **kwargs)
+                except self.exception as _:
+                    exc = _
+                    if self.logfun is not None:
+                        self.logfun(exc)
+                    self.sleep()
+                    continue
+            if PY3:
+                raise exc
+            else:
+                raise
+
+        # This way the user of the decorated function can change config
+        # parameters.
+        wrapper.decorator = self
+        return wrapper
+
+
+@retry(exception=psutil.NoSuchProcess, logfun=None, timeout=GLOBAL_TIMEOUT,
+       interval=0.001)
+def wait_for_pid(pid):
+    """Wait for pid to show up in the process list then return.
+    Used in the test suite to give time the sub process to initialize.
+    """
+    psutil.Process(pid)
+    if WINDOWS:
+        # give it some more time to allow better initialization
+        time.sleep(0.01)
+
+
+@retry(exception=(EnvironmentError, AssertionError), logfun=None,
+       timeout=GLOBAL_TIMEOUT, interval=0.001)
+def wait_for_file(fname, delete=True, empty=False):
+    """Wait for a file to be written on disk with some content."""
+    with open(fname, "rb") as f:
+        data = f.read()
+    if not empty:
+        assert data
+    if delete:
+        os.remove(fname)
+    return data
+
+
+@retry(exception=AssertionError, logfun=None, timeout=GLOBAL_TIMEOUT,
+       interval=0.001)
+def call_until(fun, expr):
+    """Keep calling function for timeout secs and exit if eval()
+    expression is True.
+    """
+    ret = fun()
+    assert eval(expr)
+    return ret
+
+
+# ===================================================================
+# --- fs
+# ===================================================================
+
+
+def safe_rmpath(path):
+    "Convenience function for removing temporary test files or dirs"
+    try:
+        st = os.stat(path)
+        if stat.S_ISDIR(st.st_mode):
+            os.rmdir(path)
+        else:
+            os.remove(path)
+    except OSError as err:
+        if err.errno != errno.ENOENT:
+            raise
+
+
+def safe_mkdir(dir):
+    "Convenience function for creating a directory"
+    try:
+        os.mkdir(dir)
+    except OSError as err:
+        if err.errno != errno.EEXIST:
+            raise
+
+
+@contextlib.contextmanager
+def chdir(dirname):
+    "Context manager which temporarily changes the current directory."
+    curdir = os.getcwd()
+    try:
+        os.chdir(dirname)
+        yield
+    finally:
+        os.chdir(curdir)
+
+
+def create_exe(outpath, c_code=None):
+    """Creates an executable file in the given location."""
+    assert not os.path.exists(outpath), outpath
+    if c_code:
+        if not which("gcc"):
+            raise ValueError("gcc is not installed")
+        if isinstance(c_code, bool):        # c_code is True
+            c_code = textwrap.dedent(
+                """
+                #include <unistd.h>
+                int main() {
+                    pause();
+                    return 1;
+                }
+                """)
+        assert isinstance(c_code, str), c_code
+        with tempfile.NamedTemporaryFile(
+                suffix='.c', delete=False, mode='wt') as f:
+            f.write(c_code)
+        try:
+            subprocess.check_call(["gcc", f.name, "-o", outpath])
+        finally:
+            safe_rmpath(f.name)
+    else:
+        # copy python executable
+        shutil.copyfile(PYTHON_EXE, outpath)
+        if POSIX:
+            st = os.stat(outpath)
+            os.chmod(outpath, st.st_mode | stat.S_IEXEC)
+
+
+def unique_filename(prefix=TESTFILE_PREFIX, suffix=""):
+    return tempfile.mktemp(prefix=prefix, suffix=suffix)
+
+
+# ===================================================================
+# --- testing
+# ===================================================================
+
+
+class TestCase(unittest.TestCase):
+
+    # Print a full path representation of the single unit tests
+    # being run.
+    def __str__(self):
+        return "%s.%s.%s" % (
+            self.__class__.__module__, self.__class__.__name__,
+            self._testMethodName)
+
+    # assertRaisesRegexp renamed to assertRaisesRegex in 3.3;
+    # add support for the new name.
+    if not hasattr(unittest.TestCase, 'assertRaisesRegex'):
+        assertRaisesRegex = unittest.TestCase.assertRaisesRegexp
+
+
+# override default unittest.TestCase
+unittest.TestCase = TestCase
+
+
+def _setup_tests():
+    if 'PSUTIL_TESTING' not in os.environ:
+        # This won't work on Windows but set_testing() below will do it.
+        os.environ['PSUTIL_TESTING'] = '1'
+    psutil._psplatform.cext.set_testing()
+
+
+def get_suite():
+    testmods = [os.path.splitext(x)[0] for x in os.listdir(HERE)
+                if x.endswith('.py') and x.startswith('test_') and not
+                x.startswith('test_memory_leaks')]
+    if "WHEELHOUSE_UPLOADER_USERNAME" in os.environ:
+        testmods = [x for x in testmods if not x.endswith((
+                    "osx", "posix", "linux"))]
+    suite = unittest.TestSuite()
+    for tm in testmods:
+        # ...so that the full test paths are printed on screen
+        tm = "psutil.tests.%s" % tm
+        suite.addTest(unittest.defaultTestLoader.loadTestsFromName(tm))
+    return suite
+
+
+def run_suite():
+    _setup_tests()
+    result = unittest.TextTestRunner(verbosity=VERBOSITY).run(get_suite())
+    success = result.wasSuccessful()
+    sys.exit(0 if success else 1)
+
+
+def run_test_module_by_name(name):
+    # testmodules = [os.path.splitext(x)[0] for x in os.listdir(HERE)
+    #                if x.endswith('.py') and x.startswith('test_')]
+    _setup_tests()
+    name = os.path.splitext(os.path.basename(name))[0]
+    suite = unittest.TestSuite()
+    suite.addTest(unittest.defaultTestLoader.loadTestsFromName(name))
+    result = unittest.TextTestRunner(verbosity=VERBOSITY).run(suite)
+    success = result.wasSuccessful()
+    sys.exit(0 if success else 1)
+
+
+def retry_before_failing(retries=NO_RETRIES):
+    """Decorator which runs a test function and retries N times before
+    actually failing.
+    """
+    return retry(exception=AssertionError, timeout=None, retries=retries)
+
+
+def skip_on_access_denied(only_if=None):
+    """Decorator to Ignore AccessDenied exceptions."""
+    def decorator(fun):
+        @functools.wraps(fun)
+        def wrapper(*args, **kwargs):
+            try:
+                return fun(*args, **kwargs)
+            except psutil.AccessDenied:
+                if only_if is not None:
+                    if not only_if:
+                        raise
+                raise unittest.SkipTest("raises AccessDenied")
+        return wrapper
+    return decorator
+
+
+def skip_on_not_implemented(only_if=None):
+    """Decorator to Ignore NotImplementedError exceptions."""
+    def decorator(fun):
+        @functools.wraps(fun)
+        def wrapper(*args, **kwargs):
+            try:
+                return fun(*args, **kwargs)
+            except NotImplementedError:
+                if only_if is not None:
+                    if not only_if:
+                        raise
+                msg = "%r was skipped because it raised NotImplementedError" \
+                      % fun.__name__
+                raise unittest.SkipTest(msg)
+        return wrapper
+    return decorator
+
+
+# ===================================================================
+# --- network
+# ===================================================================
+
+
+def get_free_port(host='127.0.0.1'):
+    """Return an unused TCP port."""
+    with contextlib.closing(socket.socket()) as sock:
+        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        sock.bind((host, 0))
+        return sock.getsockname()[1]
+
+
+@contextlib.contextmanager
+def unix_socket_path(suffix=""):
+    """A context manager which returns a non-existent file name
+    and tries to delete it on exit.
+    """
+    assert psutil.POSIX
+    path = unique_filename(suffix=suffix)
+    try:
+        yield path
+    finally:
+        try:
+            os.unlink(path)
+        except OSError:
+            pass
+
+
+def bind_socket(family=AF_INET, type=SOCK_STREAM, addr=None):
+    """Binds a generic socket."""
+    if addr is None and family in (AF_INET, AF_INET6):
+        addr = ("", 0)
+    sock = socket.socket(family, type)
+    try:
+        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        sock.bind(addr)
+        if type == socket.SOCK_STREAM:
+            sock.listen(10)
+        return sock
+    except Exception:
+        sock.close()
+        raise
+
+
+def bind_unix_socket(name, type=socket.SOCK_STREAM):
+    """Bind a UNIX socket."""
+    assert psutil.POSIX
+    assert not os.path.exists(name), name
+    sock = socket.socket(socket.AF_UNIX, type)
+    try:
+        sock.bind(name)
+        if type == socket.SOCK_STREAM:
+            sock.listen(10)
+    except Exception:
+        sock.close()
+        raise
+    return sock
+
+
+def tcp_socketpair(family, addr=("", 0)):
+    """Build a pair of TCP sockets connected to each other.
+    Return a (server, client) tuple.
+    """
+    with contextlib.closing(socket.socket(family, SOCK_STREAM)) as ll:
+        ll.bind(addr)
+        ll.listen(10)
+        addr = ll.getsockname()
+        c = socket.socket(family, SOCK_STREAM)
+        try:
+            c.connect(addr)
+            caddr = c.getsockname()
+            while True:
+                a, addr = ll.accept()
+                # check that we've got the correct client
+                if addr == caddr:
+                    return (a, c)
+                a.close()
+        except OSError:
+            c.close()
+            raise
+
+
+def unix_socketpair(name):
+    """Build a pair of UNIX sockets connected to each other through
+    the same UNIX file name.
+    Return a (server, client) tuple.
+    """
+    assert psutil.POSIX
+    server = client = None
+    try:
+        server = bind_unix_socket(name, type=socket.SOCK_STREAM)
+        server.setblocking(0)
+        client = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        client.setblocking(0)
+        client.connect(name)
+        # new = server.accept()
+    except Exception:
+        if server is not None:
+            server.close()
+        if client is not None:
+            client.close()
+        raise
+    return (server, client)
+
+
+@contextlib.contextmanager
+def create_sockets():
+    """Open as many socket families / types as possible."""
+    socks = []
+    fname1 = fname2 = None
+    try:
+        socks.append(bind_socket(socket.AF_INET, socket.SOCK_STREAM))
+        socks.append(bind_socket(socket.AF_INET, socket.SOCK_DGRAM))
+        if supports_ipv6():
+            socks.append(bind_socket(socket.AF_INET6, socket.SOCK_STREAM))
+            socks.append(bind_socket(socket.AF_INET6, socket.SOCK_DGRAM))
+        if POSIX and HAS_CONNECTIONS_UNIX:
+            fname1 = unix_socket_path().__enter__()
+            fname2 = unix_socket_path().__enter__()
+            s1, s2 = unix_socketpair(fname1)
+            s3 = bind_unix_socket(fname2, type=socket.SOCK_DGRAM)
+            # self.addCleanup(safe_rmpath, fname1)
+            # self.addCleanup(safe_rmpath, fname2)
+            for s in (s1, s2, s3):
+                socks.append(s)
+        yield socks
+    finally:
+        for s in socks:
+            s.close()
+        if fname1 is not None:
+            safe_rmpath(fname1)
+        if fname2 is not None:
+            safe_rmpath(fname2)
+
+
+def check_net_address(addr, family):
+    """Check a net address validity. Supported families are IPv4,
+    IPv6 and MAC addresses.
+    """
+    import ipaddress  # python >= 3.3 / requires "pip install ipaddress"
+    if enum and PY3:
+        assert isinstance(family, enum.IntEnum), family
+    if family == socket.AF_INET:
+        octs = [int(x) for x in addr.split('.')]
+        assert len(octs) == 4, addr
+        for num in octs:
+            assert 0 <= num <= 255, addr
+        if not PY3:
+            addr = unicode(addr)
+        ipaddress.IPv4Address(addr)
+    elif family == socket.AF_INET6:
+        assert isinstance(addr, str), addr
+        if not PY3:
+            addr = unicode(addr)
+        ipaddress.IPv6Address(addr)
+    elif family == psutil.AF_LINK:
+        assert re.match(r'([a-fA-F0-9]{2}[:|\-]?){6}', addr) is not None, addr
+    else:
+        raise ValueError("unknown family %r", family)
+
+
+def check_connection_ntuple(conn):
+    """Check validity of a connection namedtuple."""
+    # check ntuple
+    assert len(conn) in (6, 7), conn
+    has_pid = len(conn) == 7
+    has_fd = getattr(conn, 'fd', -1) != -1
+    assert conn[0] == conn.fd
+    assert conn[1] == conn.family
+    assert conn[2] == conn.type
+    assert conn[3] == conn.laddr
+    assert conn[4] == conn.raddr
+    assert conn[5] == conn.status
+    if has_pid:
+        assert conn[6] == conn.pid
+
+    # check fd
+    if has_fd:
+        assert conn.fd >= 0, conn
+        if hasattr(socket, 'fromfd') and not WINDOWS:
+            try:
+                dupsock = socket.fromfd(conn.fd, conn.family, conn.type)
+            except (socket.error, OSError) as err:
+                if err.args[0] != errno.EBADF:
+                    raise
+            else:
+                with contextlib.closing(dupsock):
+                    assert dupsock.family == conn.family
+                    assert dupsock.type == conn.type
+
+    # check family
+    assert conn.family in (AF_INET, AF_INET6, AF_UNIX), repr(conn.family)
+    if conn.family in (AF_INET, AF_INET6):
+        # actually try to bind the local socket; ignore IPv6
+        # sockets as their address might be represented as
+        # an IPv4-mapped-address (e.g. "::127.0.0.1")
+        # and that's rejected by bind()
+        if conn.family == AF_INET:
+            s = socket.socket(conn.family, conn.type)
+            with contextlib.closing(s):
+                try:
+                    s.bind((conn.laddr[0], 0))
+                except socket.error as err:
+                    if err.errno != errno.EADDRNOTAVAIL:
+                        raise
+    elif conn.family == AF_UNIX:
+        assert conn.status == psutil.CONN_NONE, conn.status
+
+    # check type (SOCK_SEQPACKET may happen in case of AF_UNIX socks)
+    assert conn.type in (SOCK_STREAM, SOCK_DGRAM, SOCK_SEQPACKET), \
+        repr(conn.type)
+    if conn.type == SOCK_DGRAM:
+        assert conn.status == psutil.CONN_NONE, conn.status
+
+    # check laddr (IP address and port sanity)
+    for addr in (conn.laddr, conn.raddr):
+        if conn.family in (AF_INET, AF_INET6):
+            assert isinstance(addr, tuple), addr
+            if not addr:
+                continue
+            assert isinstance(addr.port, int), addr.port
+            assert 0 <= addr.port <= 65535, addr.port
+            check_net_address(addr.ip, conn.family)
+        elif conn.family == AF_UNIX:
+            assert isinstance(addr, str), addr
+
+    # check status
+    assert isinstance(conn.status, str), conn
+    valids = [getattr(psutil, x) for x in dir(psutil) if x.startswith('CONN_')]
+    assert conn.status in valids, conn
+
+
+# ===================================================================
+# --- compatibility
+# ===================================================================
+
+
+def reload_module(module):
+    """Backport of importlib.reload of Python 3.3+."""
+    try:
+        import importlib
+        if not hasattr(importlib, 'reload'):  # python <=3.3
+            raise ImportError
+    except ImportError:
+        import imp
+        return imp.reload(module)
+    else:
+        return importlib.reload(module)
+
+
+def import_module_by_path(path):
+    name = os.path.splitext(os.path.basename(path))[0]
+    if sys.version_info[0] == 2:
+        import imp
+        return imp.load_source(name, path)
+    elif sys.version_info[:2] <= (3, 4):
+        from importlib.machinery import SourceFileLoader
+        return SourceFileLoader(name, path).load_module()
+    else:
+        import importlib.util
+        spec = importlib.util.spec_from_file_location(name, path)
+        mod = importlib.util.module_from_spec(spec)
+        spec.loader.exec_module(mod)
+        return mod
+
+
+# ===================================================================
+# --- others
+# ===================================================================
+
+
+def warn(msg):
+    """Raise a warning msg."""
+    warnings.warn(msg, UserWarning)
+
+
+def is_namedtuple(x):
+    """Check if object is an instance of namedtuple."""
+    t = type(x)
+    b = t.__bases__
+    if len(b) != 1 or b[0] != tuple:
+        return False
+    f = getattr(t, '_fields', None)
+    if not isinstance(f, tuple):
+        return False
+    return all(type(n) == str for n in f)
+
+
+if POSIX:
+    @contextlib.contextmanager
+    def copyload_shared_lib(dst_prefix=TESTFILE_PREFIX):
+        """Ctx manager which picks up a random shared CO lib used
+        by this process, copies it in another location and loads it
+        in memory via ctypes. Return the new absolutized path.
+        """
+        ext = ".so"
+        dst = tempfile.mktemp(prefix=dst_prefix, suffix=ext)
+        libs = [x.path for x in psutil.Process().memory_maps() if
+                os.path.splitext(x.path)[1] == ext and
+                'python' in x.path.lower()]
+        src = random.choice(libs)
+        shutil.copyfile(src, dst)
+        try:
+            ctypes.CDLL(dst)
+            yield dst
+        finally:
+            safe_rmpath(dst)
+else:
+    @contextlib.contextmanager
+    def copyload_shared_lib(dst_prefix=TESTFILE_PREFIX):
+        """Ctx manager which picks up a random shared DLL lib used
+        by this process, copies it in another location and loads it
+        in memory via ctypes.
+        Return the new absolutized, normcased path.
+        """
+        from ctypes import wintypes
+        from ctypes import WinError
+        ext = ".dll"
+        dst = tempfile.mktemp(prefix=dst_prefix, suffix=ext)
+        libs = [x.path for x in psutil.Process().memory_maps() if
+                os.path.splitext(x.path)[1].lower() == ext and
+                'python' in os.path.basename(x.path).lower() and
+                'wow64' not in x.path.lower()]
+        src = random.choice(libs)
+        shutil.copyfile(src, dst)
+        cfile = None
+        try:
+            cfile = ctypes.WinDLL(dst)
+            yield dst
+        finally:
+            # Work around OverflowError:
+            # - https://ci.appveyor.com/project/giampaolo/psutil/build/1207/
+            #       job/o53330pbnri9bcw7
+            # - http://bugs.python.org/issue30286
+            # - http://stackoverflow.com/questions/23522055
+            if cfile is not None:
+                FreeLibrary = ctypes.windll.kernel32.FreeLibrary
+                FreeLibrary.argtypes = [wintypes.HMODULE]
+                ret = FreeLibrary(cfile._handle)
+                if ret == 0:
+                    WinError()
+            safe_rmpath(dst)
diff --git a/psutil/tests/__main__.py b/psutil/tests/__main__.py
new file mode 100755
index 00000000..62fe0742
--- /dev/null
+++ b/psutil/tests/__main__.py
@@ -0,0 +1,94 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Run unit tests. This is invoked by:
+
+$ python -m psutil.tests
+"""
+
+import contextlib
+import optparse
+import os
+import ssl
+import sys
+import tempfile
+try:
+    from urllib.request import urlopen  # py3
+except ImportError:
+    from urllib2 import urlopen
+
+from psutil.tests import PYTHON_EXE
+from psutil.tests import run_suite
+
+
+HERE = os.path.abspath(os.path.dirname(__file__))
+GET_PIP_URL = "https://bootstrap.pypa.io/get-pip.py"
+TEST_DEPS = []
+if sys.version_info[:2] == (2, 6):
+    TEST_DEPS.extend(["ipaddress", "unittest2", "argparse", "mock==1.0.1"])
+elif sys.version_info[:2] == (2, 7) or sys.version_info[:2] <= (3, 2):
+    TEST_DEPS.extend(["ipaddress", "mock"])
+
+
+def install_pip():
+    try:
+        import pip  # NOQA
+    except ImportError:
+        f = tempfile.NamedTemporaryFile(suffix='.py')
+        with contextlib.closing(f):
+            print("downloading %s to %s" % (GET_PIP_URL, f.name))
+            if hasattr(ssl, '_create_unverified_context'):
+                ctx = ssl._create_unverified_context()
+            else:
+                ctx = None
+            kwargs = dict(context=ctx) if ctx else {}
+            req = urlopen(GET_PIP_URL, **kwargs)
+            data = req.read()
+            f.write(data)
+            f.flush()
+
+            print("installing pip")
+            code = os.system('%s %s --user' % (PYTHON_EXE, f.name))
+            return code
+
+
+def install_test_deps(deps=None):
+    """Install test dependencies via pip."""
+    if deps is None:
+        deps = TEST_DEPS
+    deps = set(deps)
+    if deps:
+        is_venv = hasattr(sys, 'real_prefix')
+        opts = "--user" if not is_venv else ""
+        install_pip()
+        code = os.system('%s -m pip install %s --upgrade %s' % (
+            PYTHON_EXE, opts, " ".join(deps)))
+        return code
+
+
+def main():
+    usage = "%s -m psutil.tests [opts]" % PYTHON_EXE
+    parser = optparse.OptionParser(usage=usage, description="run unit tests")
+    parser.add_option("-i", "--install-deps",
+                      action="store_true", default=False,
+                      help="don't print status messages to stdout")
+
+    opts, args = parser.parse_args()
+    if opts.install_deps:
+        install_pip()
+        install_test_deps()
+    else:
+        for dep in TEST_DEPS:
+            try:
+                __import__(dep.split("==")[0])
+            except ImportError:
+                sys.exit("%r lib is not installed; run %s -m psutil.tests "
+                         "--install-deps" % (dep, PYTHON_EXE))
+        run_suite()
+
+
+main()
diff --git a/psutil/tests/test_aix.py b/psutil/tests/test_aix.py
new file mode 100755
index 00000000..7a8a4c33
--- /dev/null
+++ b/psutil/tests/test_aix.py
@@ -0,0 +1,121 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'
+# Copyright (c) 2017, Arnon Yaari
+# All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""AIX specific tests."""
+
+import re
+
+from psutil import AIX
+from psutil.tests import run_test_module_by_name
+from psutil.tests import sh
+from psutil.tests import unittest
+import psutil
+
+
+@unittest.skipIf(not AIX, "AIX only")
+class AIXSpecificTestCase(unittest.TestCase):
+
+    def test_virtual_memory(self):
+        out = sh('/usr/bin/svmon -O unit=KB')
+        re_pattern = "memory\s*"
+        for field in ("size inuse free pin virtual available mmode").split():
+            re_pattern += "(?P<%s>\S+)\s+" % (field,)
+        matchobj = re.search(re_pattern, out)
+
+        self.assertIsNotNone(
+            matchobj, "svmon command returned unexpected output")
+
+        KB = 1024
+        total = int(matchobj.group("size")) * KB
+        available = int(matchobj.group("available")) * KB
+        used = int(matchobj.group("inuse")) * KB
+        free = int(matchobj.group("free")) * KB
+
+        psutil_result = psutil.virtual_memory()
+
+        # MEMORY_TOLERANCE from psutil.tests is not enough. For some reason
+        # we're seeing differences of ~1.2 MB. 2 MB is still a good tolerance
+        # when compared to GBs.
+        MEMORY_TOLERANCE = 2 * KB * KB   # 2 MB
+        self.assertEqual(psutil_result.total, total)
+        self.assertAlmostEqual(
+            psutil_result.used, used, delta=MEMORY_TOLERANCE)
+        self.assertAlmostEqual(
+            psutil_result.available, available, delta=MEMORY_TOLERANCE)
+        self.assertAlmostEqual(
+            psutil_result.free, free, delta=MEMORY_TOLERANCE)
+
+    def test_swap_memory(self):
+        out = sh('/usr/sbin/lsps -a')
+        # From the man page, "The size is given in megabytes" so we assume
+        # we'll always have 'MB' in the result
+        # TODO maybe try to use "swap -l" to check "used" too, but its units
+        # are not guaranteed to be "MB" so parsing may not be consistent
+        matchobj = re.search("(?P<space>\S+)\s+"
+                             "(?P<vol>\S+)\s+"
+                             "(?P<vg>\S+)\s+"
+                             "(?P<size>\d+)MB", out)
+
+        self.assertIsNotNone(
+            matchobj, "lsps command returned unexpected output")
+
+        total_mb = int(matchobj.group("size"))
+        MB = 1024 ** 2
+        psutil_result = psutil.swap_memory()
+        # we divide our result by MB instead of multiplying the lsps value by
+        # MB because lsps may round down, so we round down too
+        self.assertEqual(int(psutil_result.total / MB), total_mb)
+
+    def test_cpu_stats(self):
+        out = sh('/usr/bin/mpstat -a')
+
+        re_pattern = "ALL\s*"
+        for field in ("min maj mpcs mpcr dev soft dec ph cs ics bound rq "
+                      "push S3pull S3grd S0rd S1rd S2rd S3rd S4rd S5rd "
+                      "sysc").split():
+            re_pattern += "(?P<%s>\S+)\s+" % (field,)
+        matchobj = re.search(re_pattern, out)
+
+        self.assertIsNotNone(
+            matchobj, "mpstat command returned unexpected output")
+
+        # numbers are usually in the millions so 1000 is ok for tolerance
+        CPU_STATS_TOLERANCE = 1000
+        psutil_result = psutil.cpu_stats()
+        self.assertAlmostEqual(
+            psutil_result.ctx_switches,
+            int(matchobj.group("cs")),
+            delta=CPU_STATS_TOLERANCE)
+        self.assertAlmostEqual(
+            psutil_result.syscalls,
+            int(matchobj.group("sysc")),
+            delta=CPU_STATS_TOLERANCE)
+        self.assertAlmostEqual(
+            psutil_result.interrupts,
+            int(matchobj.group("dev")),
+            delta=CPU_STATS_TOLERANCE)
+        self.assertAlmostEqual(
+            psutil_result.soft_interrupts,
+            int(matchobj.group("soft")),
+            delta=CPU_STATS_TOLERANCE)
+
+    def test_cpu_count_logical(self):
+        out = sh('/usr/bin/mpstat -a')
+        mpstat_lcpu = int(re.search("lcpu=(\d+)", out).group(1))
+        psutil_lcpu = psutil.cpu_count(logical=True)
+        self.assertEqual(mpstat_lcpu, psutil_lcpu)
+
+    def test_net_if_addrs_names(self):
+        out = sh('/etc/ifconfig -l')
+        ifconfig_names = set(out.split())
+        psutil_names = set(psutil.net_if_addrs().keys())
+        self.assertSetEqual(ifconfig_names, psutil_names)
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_bsd.py b/psutil/tests/test_bsd.py
new file mode 100755
index 00000000..d3868ada
--- /dev/null
+++ b/psutil/tests/test_bsd.py
@@ -0,0 +1,489 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# TODO: (FreeBSD) add test for comparing connections with 'sockstat' cmd.
+
+
+"""Tests specific to all BSD platforms."""
+
+
+import datetime
+import os
+import re
+import time
+
+import psutil
+from psutil import BSD
+from psutil import FREEBSD
+from psutil import NETBSD
+from psutil import OPENBSD
+from psutil.tests import get_test_subprocess
+from psutil.tests import HAS_BATTERY
+from psutil.tests import MEMORY_TOLERANCE
+from psutil.tests import reap_children
+from psutil.tests import retry_before_failing
+from psutil.tests import run_test_module_by_name
+from psutil.tests import sh
+from psutil.tests import unittest
+from psutil.tests import which
+
+
+if BSD:
+    PAGESIZE = os.sysconf("SC_PAGE_SIZE")
+    if os.getuid() == 0:  # muse requires root privileges
+        MUSE_AVAILABLE = which('muse')
+    else:
+        MUSE_AVAILABLE = False
+else:
+    MUSE_AVAILABLE = False
+
+
+def sysctl(cmdline):
+    """Expects a sysctl command with an argument and parse the result
+    returning only the value of interest.
+    """
+    result = sh("sysctl " + cmdline)
+    if FREEBSD:
+        result = result[result.find(": ") + 2:]
+    elif OPENBSD or NETBSD:
+        result = result[result.find("=") + 1:]
+    try:
+        return int(result)
+    except ValueError:
+        return result
+
+
+def muse(field):
+    """Thin wrapper around 'muse' cmdline utility."""
+    out = sh('muse')
+    for line in out.split('\n'):
+        if line.startswith(field):
+            break
+    else:
+        raise ValueError("line not found")
+    return int(line.split()[1])
+
+
+# =====================================================================
+# --- All BSD*
+# =====================================================================
+
+
+@unittest.skipIf(not BSD, "BSD only")
+class BSDSpecificTestCase(unittest.TestCase):
+    """Generic tests common to all BSD variants."""
+
+    @classmethod
+    def setUpClass(cls):
+        cls.pid = get_test_subprocess().pid
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children()
+
+    @unittest.skipIf(NETBSD, "-o lstart doesn't work on NETBSD")
+    def test_process_create_time(self):
+        output = sh("ps -o lstart -p %s" % self.pid)
+        start_ps = output.replace('STARTED', '').strip()
+        start_psutil = psutil.Process(self.pid).create_time()
+        start_psutil = time.strftime("%a %b %e %H:%M:%S %Y",
+                                     time.localtime(start_psutil))
+        self.assertEqual(start_ps, start_psutil)
+
+    def test_disks(self):
+        # test psutil.disk_usage() and psutil.disk_partitions()
+        # against "df -a"
+        def df(path):
+            out = sh('df -k "%s"' % path).strip()
+            lines = out.split('\n')
+            lines.pop(0)
+            line = lines.pop(0)
+            dev, total, used, free = line.split()[:4]
+            if dev == 'none':
+                dev = ''
+            total = int(total) * 1024
+            used = int(used) * 1024
+            free = int(free) * 1024
+            return dev, total, used, free
+
+        for part in psutil.disk_partitions(all=False):
+            usage = psutil.disk_usage(part.mountpoint)
+            dev, total, used, free = df(part.mountpoint)
+            self.assertEqual(part.device, dev)
+            self.assertEqual(usage.total, total)
+            # 10 MB tollerance
+            if abs(usage.free - free) > 10 * 1024 * 1024:
+                self.fail("psutil=%s, df=%s" % (usage.free, free))
+            if abs(usage.used - used) > 10 * 1024 * 1024:
+                self.fail("psutil=%s, df=%s" % (usage.used, used))
+
+    @unittest.skipIf(not which('sysctl'), "sysctl cmd not available")
+    def test_cpu_count_logical(self):
+        syst = sysctl("hw.ncpu")
+        self.assertEqual(psutil.cpu_count(logical=True), syst)
+
+    @unittest.skipIf(not which('sysctl'), "sysctl cmd not available")
+    def test_virtual_memory_total(self):
+        num = sysctl('hw.physmem')
+        self.assertEqual(num, psutil.virtual_memory().total)
+
+    def test_net_if_stats(self):
+        for name, stats in psutil.net_if_stats().items():
+            try:
+                out = sh("ifconfig %s" % name)
+            except RuntimeError:
+                pass
+            else:
+                self.assertEqual(stats.isup, 'RUNNING' in out, msg=out)
+                if "mtu" in out:
+                    self.assertEqual(stats.mtu,
+                                     int(re.findall(r'mtu (\d+)', out)[0]))
+
+
+# =====================================================================
+# --- FreeBSD
+# =====================================================================
+
+
+@unittest.skipIf(not FREEBSD, "FREEBSD only")
+class FreeBSDSpecificTestCase(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        cls.pid = get_test_subprocess().pid
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children()
+
+    @retry_before_failing()
+    def test_proc_memory_maps(self):
+        out = sh('procstat -v %s' % self.pid)
+        maps = psutil.Process(self.pid).memory_maps(grouped=False)
+        lines = out.split('\n')[1:]
+        while lines:
+            line = lines.pop()
+            fields = line.split()
+            _, start, stop, perms, res = fields[:5]
+            map = maps.pop()
+            self.assertEqual("%s-%s" % (start, stop), map.addr)
+            self.assertEqual(int(res), map.rss)
+            if not map.path.startswith('['):
+                self.assertEqual(fields[10], map.path)
+
+    def test_proc_exe(self):
+        out = sh('procstat -b %s' % self.pid)
+        self.assertEqual(psutil.Process(self.pid).exe(),
+                         out.split('\n')[1].split()[-1])
+
+    def test_proc_cmdline(self):
+        out = sh('procstat -c %s' % self.pid)
+        self.assertEqual(' '.join(psutil.Process(self.pid).cmdline()),
+                         ' '.join(out.split('\n')[1].split()[2:]))
+
+    def test_proc_uids_gids(self):
+        out = sh('procstat -s %s' % self.pid)
+        euid, ruid, suid, egid, rgid, sgid = out.split('\n')[1].split()[2:8]
+        p = psutil.Process(self.pid)
+        uids = p.uids()
+        gids = p.gids()
+        self.assertEqual(uids.real, int(ruid))
+        self.assertEqual(uids.effective, int(euid))
+        self.assertEqual(uids.saved, int(suid))
+        self.assertEqual(gids.real, int(rgid))
+        self.assertEqual(gids.effective, int(egid))
+        self.assertEqual(gids.saved, int(sgid))
+
+    @retry_before_failing()
+    def test_proc_ctx_switches(self):
+        tested = []
+        out = sh('procstat -r %s' % self.pid)
+        p = psutil.Process(self.pid)
+        for line in out.split('\n'):
+            line = line.lower().strip()
+            if ' voluntary context' in line:
+                pstat_value = int(line.split()[-1])
+                psutil_value = p.num_ctx_switches().voluntary
+                self.assertEqual(pstat_value, psutil_value)
+                tested.append(None)
+            elif ' involuntary context' in line:
+                pstat_value = int(line.split()[-1])
+                psutil_value = p.num_ctx_switches().involuntary
+                self.assertEqual(pstat_value, psutil_value)
+                tested.append(None)
+        if len(tested) != 2:
+            raise RuntimeError("couldn't find lines match in procstat out")
+
+    @retry_before_failing()
+    def test_proc_cpu_times(self):
+        tested = []
+        out = sh('procstat -r %s' % self.pid)
+        p = psutil.Process(self.pid)
+        for line in out.split('\n'):
+            line = line.lower().strip()
+            if 'user time' in line:
+                pstat_value = float('0.' + line.split()[-1].split('.')[-1])
+                psutil_value = p.cpu_times().user
+                self.assertEqual(pstat_value, psutil_value)
+                tested.append(None)
+            elif 'system time' in line:
+                pstat_value = float('0.' + line.split()[-1].split('.')[-1])
+                psutil_value = p.cpu_times().system
+                self.assertEqual(pstat_value, psutil_value)
+                tested.append(None)
+        if len(tested) != 2:
+            raise RuntimeError("couldn't find lines match in procstat out")
+
+    # --- virtual_memory(); tests against sysctl
+
+    @retry_before_failing()
+    def test_vmem_active(self):
+        syst = sysctl("vm.stats.vm.v_active_count") * PAGESIZE
+        self.assertAlmostEqual(psutil.virtual_memory().active, syst,
+                               delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_vmem_inactive(self):
+        syst = sysctl("vm.stats.vm.v_inactive_count") * PAGESIZE
+        self.assertAlmostEqual(psutil.virtual_memory().inactive, syst,
+                               delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_vmem_wired(self):
+        syst = sysctl("vm.stats.vm.v_wire_count") * PAGESIZE
+        self.assertAlmostEqual(psutil.virtual_memory().wired, syst,
+                               delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_vmem_cached(self):
+        syst = sysctl("vm.stats.vm.v_cache_count") * PAGESIZE
+        self.assertAlmostEqual(psutil.virtual_memory().cached, syst,
+                               delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_vmem_free(self):
+        syst = sysctl("vm.stats.vm.v_free_count") * PAGESIZE
+        self.assertAlmostEqual(psutil.virtual_memory().free, syst,
+                               delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_vmem_buffers(self):
+        syst = sysctl("vfs.bufspace")
+        self.assertAlmostEqual(psutil.virtual_memory().buffers, syst,
+                               delta=MEMORY_TOLERANCE)
+
+    # --- virtual_memory(); tests against muse
+
+    @unittest.skipIf(not MUSE_AVAILABLE, "muse not installed")
+    def test_muse_vmem_total(self):
+        num = muse('Total')
+        self.assertEqual(psutil.virtual_memory().total, num)
+
+    @unittest.skipIf(not MUSE_AVAILABLE, "muse not installed")
+    @retry_before_failing()
+    def test_muse_vmem_active(self):
+        num = muse('Active')
+        self.assertAlmostEqual(psutil.virtual_memory().active, num,
+                               delta=MEMORY_TOLERANCE)
+
+    @unittest.skipIf(not MUSE_AVAILABLE, "muse not installed")
+    @retry_before_failing()
+    def test_muse_vmem_inactive(self):
+        num = muse('Inactive')
+        self.assertAlmostEqual(psutil.virtual_memory().inactive, num,
+                               delta=MEMORY_TOLERANCE)
+
+    @unittest.skipIf(not MUSE_AVAILABLE, "muse not installed")
+    @retry_before_failing()
+    def test_muse_vmem_wired(self):
+        num = muse('Wired')
+        self.assertAlmostEqual(psutil.virtual_memory().wired, num,
+                               delta=MEMORY_TOLERANCE)
+
+    @unittest.skipIf(not MUSE_AVAILABLE, "muse not installed")
+    @retry_before_failing()
+    def test_muse_vmem_cached(self):
+        num = muse('Cache')
+        self.assertAlmostEqual(psutil.virtual_memory().cached, num,
+                               delta=MEMORY_TOLERANCE)
+
+    @unittest.skipIf(not MUSE_AVAILABLE, "muse not installed")
+    @retry_before_failing()
+    def test_muse_vmem_free(self):
+        num = muse('Free')
+        self.assertAlmostEqual(psutil.virtual_memory().free, num,
+                               delta=MEMORY_TOLERANCE)
+
+    @unittest.skipIf(not MUSE_AVAILABLE, "muse not installed")
+    @retry_before_failing()
+    def test_muse_vmem_buffers(self):
+        num = muse('Buffer')
+        self.assertAlmostEqual(psutil.virtual_memory().buffers, num,
+                               delta=MEMORY_TOLERANCE)
+
+    def test_cpu_stats_ctx_switches(self):
+        self.assertAlmostEqual(psutil.cpu_stats().ctx_switches,
+                               sysctl('vm.stats.sys.v_swtch'), delta=1000)
+
+    def test_cpu_stats_interrupts(self):
+        self.assertAlmostEqual(psutil.cpu_stats().interrupts,
+                               sysctl('vm.stats.sys.v_intr'), delta=1000)
+
+    def test_cpu_stats_soft_interrupts(self):
+        self.assertAlmostEqual(psutil.cpu_stats().soft_interrupts,
+                               sysctl('vm.stats.sys.v_soft'), delta=1000)
+
+    def test_cpu_stats_syscalls(self):
+        self.assertAlmostEqual(psutil.cpu_stats().syscalls,
+                               sysctl('vm.stats.sys.v_syscall'), delta=1000)
+
+    # def test_cpu_stats_traps(self):
+    #    self.assertAlmostEqual(psutil.cpu_stats().traps,
+    #                           sysctl('vm.stats.sys.v_trap'), delta=1000)
+
+    # --- others
+
+    def test_boot_time(self):
+        s = sysctl('sysctl kern.boottime')
+        s = s[s.find(" sec = ") + 7:]
+        s = s[:s.find(',')]
+        btime = int(s)
+        self.assertEqual(btime, psutil.boot_time())
+
+    # --- sensors_battery
+
+    @unittest.skipIf(not HAS_BATTERY, "no battery")
+    def test_sensors_battery(self):
+        def secs2hours(secs):
+            m, s = divmod(secs, 60)
+            h, m = divmod(m, 60)
+            return "%d:%02d" % (h, m)
+
+        out = sh("acpiconf -i 0")
+        fields = dict([(x.split('\t')[0], x.split('\t')[-1])
+                       for x in out.split("\n")])
+        metrics = psutil.sensors_battery()
+        percent = int(fields['Remaining capacity:'].replace('%', ''))
+        remaining_time = fields['Remaining time:']
+        self.assertEqual(metrics.percent, percent)
+        if remaining_time == 'unknown':
+            self.assertEqual(metrics.secsleft, psutil.POWER_TIME_UNLIMITED)
+        else:
+            self.assertEqual(secs2hours(metrics.secsleft), remaining_time)
+
+    @unittest.skipIf(not HAS_BATTERY, "no battery")
+    def test_sensors_battery_against_sysctl(self):
+        self.assertEqual(psutil.sensors_battery().percent,
+                         sysctl("hw.acpi.battery.life"))
+        self.assertEqual(psutil.sensors_battery().power_plugged,
+                         sysctl("hw.acpi.acline") == 1)
+        secsleft = psutil.sensors_battery().secsleft
+        if secsleft < 0:
+            self.assertEqual(sysctl("hw.acpi.battery.time"), -1)
+        else:
+            self.assertEqual(secsleft, sysctl("hw.acpi.battery.time") * 60)
+
+    @unittest.skipIf(HAS_BATTERY, "has battery")
+    def test_sensors_battery_no_battery(self):
+        # If no battery is present one of these calls is supposed
+        # to fail, see:
+        # https://github.com/giampaolo/psutil/issues/1074
+        with self.assertRaises(RuntimeError):
+            sysctl("hw.acpi.battery.life")
+            sysctl("hw.acpi.battery.time")
+            sysctl("hw.acpi.acline")
+        self.assertIsNone(psutil.sensors_battery())
+
+
+# =====================================================================
+# --- OpenBSD
+# =====================================================================
+
+
+@unittest.skipIf(not OPENBSD, "OPENBSD only")
+class OpenBSDSpecificTestCase(unittest.TestCase):
+
+    def test_boot_time(self):
+        s = sysctl('kern.boottime')
+        sys_bt = datetime.datetime.strptime(s, "%a %b %d %H:%M:%S %Y")
+        psutil_bt = datetime.datetime.fromtimestamp(psutil.boot_time())
+        self.assertEqual(sys_bt, psutil_bt)
+
+
+# =====================================================================
+# --- NetBSD
+# =====================================================================
+
+
+@unittest.skipIf(not NETBSD, "NETBSD only")
+class NetBSDSpecificTestCase(unittest.TestCase):
+
+    @staticmethod
+    def parse_meminfo(look_for):
+        with open('/proc/meminfo', 'rb') as f:
+            for line in f:
+                if line.startswith(look_for):
+                    return int(line.split()[1]) * 1024
+        raise ValueError("can't find %s" % look_for)
+
+    def test_vmem_total(self):
+        self.assertEqual(
+            psutil.virtual_memory().total, self.parse_meminfo("MemTotal:"))
+
+    def test_vmem_free(self):
+        self.assertAlmostEqual(
+            psutil.virtual_memory().free, self.parse_meminfo("MemFree:"),
+            delta=MEMORY_TOLERANCE)
+
+    def test_vmem_buffers(self):
+        self.assertAlmostEqual(
+            psutil.virtual_memory().buffers, self.parse_meminfo("Buffers:"),
+            delta=MEMORY_TOLERANCE)
+
+    def test_vmem_shared(self):
+        self.assertAlmostEqual(
+            psutil.virtual_memory().shared, self.parse_meminfo("MemShared:"),
+            delta=MEMORY_TOLERANCE)
+
+    def test_swapmem_total(self):
+        self.assertAlmostEqual(
+            psutil.swap_memory().total, self.parse_meminfo("SwapTotal:"),
+            delta=MEMORY_TOLERANCE)
+
+    def test_swapmem_free(self):
+        self.assertAlmostEqual(
+            psutil.swap_memory().free, self.parse_meminfo("SwapFree:"),
+            delta=MEMORY_TOLERANCE)
+
+    def test_swapmem_used(self):
+        smem = psutil.swap_memory()
+        self.assertEqual(smem.used, smem.total - smem.free)
+
+    def test_cpu_stats_interrupts(self):
+        with open('/proc/stat', 'rb') as f:
+            for line in f:
+                if line.startswith(b'intr'):
+                    interrupts = int(line.split()[1])
+                    break
+            else:
+                raise ValueError("couldn't find line")
+        self.assertAlmostEqual(
+            psutil.cpu_stats().interrupts, interrupts, delta=1000)
+
+    def test_cpu_stats_ctx_switches(self):
+        with open('/proc/stat', 'rb') as f:
+            for line in f:
+                if line.startswith(b'ctxt'):
+                    ctx_switches = int(line.split()[1])
+                    break
+            else:
+                raise ValueError("couldn't find line")
+        self.assertAlmostEqual(
+            psutil.cpu_stats().ctx_switches, ctx_switches, delta=1000)
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_connections.py b/psutil/tests/test_connections.py
new file mode 100755
index 00000000..176e2664
--- /dev/null
+++ b/psutil/tests/test_connections.py
@@ -0,0 +1,525 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Tests for net_connections() and Process.connections() APIs."""
+
+import os
+import socket
+import textwrap
+from contextlib import closing
+from socket import AF_INET
+from socket import AF_INET6
+from socket import SOCK_DGRAM
+from socket import SOCK_STREAM
+
+import psutil
+from psutil import FREEBSD
+from psutil import LINUX
+from psutil import NETBSD
+from psutil import OPENBSD
+from psutil import OSX
+from psutil import POSIX
+from psutil import SUNOS
+from psutil import WINDOWS
+from psutil._common import supports_ipv6
+from psutil._compat import PY3
+from psutil.tests import AF_UNIX
+from psutil.tests import bind_socket
+from psutil.tests import bind_unix_socket
+from psutil.tests import check_connection_ntuple
+from psutil.tests import create_sockets
+from psutil.tests import get_free_port
+from psutil.tests import HAS_CONNECTIONS_UNIX
+from psutil.tests import pyrun
+from psutil.tests import reap_children
+from psutil.tests import run_test_module_by_name
+from psutil.tests import safe_rmpath
+from psutil.tests import skip_on_access_denied
+from psutil.tests import tcp_socketpair
+from psutil.tests import TESTFN
+from psutil.tests import TRAVIS
+from psutil.tests import unittest
+from psutil.tests import unix_socket_path
+from psutil.tests import unix_socketpair
+from psutil.tests import wait_for_file
+
+
+thisproc = psutil.Process()
+
+
+class Base(object):
+
+    def setUp(self):
+        if not NETBSD:
+            # NetBSD opens a UNIX socket to /var/log/run.
+            cons = thisproc.connections(kind='all')
+            assert not cons, cons
+
+    def tearDown(self):
+        safe_rmpath(TESTFN)
+        reap_children()
+        if not NETBSD:
+            # Make sure we closed all resources.
+            # NetBSD opens a UNIX socket to /var/log/run.
+            cons = thisproc.connections(kind='all')
+            assert not cons, cons
+
+    def get_conn_from_sock(self, sock):
+        cons = thisproc.connections(kind='all')
+        smap = dict([(c.fd, c) for c in cons])
+        if NETBSD:
+            # NetBSD opens a UNIX socket to /var/log/run
+            # so there may be more connections.
+            return smap[sock.fileno()]
+        else:
+            self.assertEqual(len(cons), 1)
+            if cons[0].fd != -1:
+                self.assertEqual(smap[sock.fileno()].fd, sock.fileno())
+            return cons[0]
+
+    def check_socket(self, sock, conn=None):
+        """Given a socket, makes sure it matches the one obtained
+        via psutil. It assumes this process created one connection
+        only (the one supposed to be checked).
+        """
+        if conn is None:
+            conn = self.get_conn_from_sock(sock)
+        check_connection_ntuple(conn)
+
+        # fd, family, type
+        if conn.fd != -1:
+            self.assertEqual(conn.fd, sock.fileno())
+        self.assertEqual(conn.family, sock.family)
+        # see: http://bugs.python.org/issue30204
+        self.assertEqual(
+            conn.type, sock.getsockopt(socket.SOL_SOCKET, socket.SO_TYPE))
+
+        # local address
+        laddr = sock.getsockname()
+        if not laddr and PY3 and isinstance(laddr, bytes):
+            # See: http://bugs.python.org/issue30205
+            laddr = laddr.decode()
+        if sock.family == AF_INET6:
+            laddr = laddr[:2]
+        if sock.family == AF_UNIX and OPENBSD:
+            # No addresses are set for UNIX sockets on OpenBSD.
+            pass
+        else:
+            self.assertEqual(conn.laddr, laddr)
+
+        # XXX Solaris can't retrieve system-wide UNIX sockets
+        if sock.family == AF_UNIX and HAS_CONNECTIONS_UNIX:
+            cons = thisproc.connections(kind='all')
+            self.compare_procsys_connections(os.getpid(), cons)
+        return conn
+
+    def compare_procsys_connections(self, pid, proc_cons, kind='all'):
+        """Given a process PID and its list of connections compare
+        those against system-wide connections retrieved via
+        psutil.net_connections.
+        """
+        try:
+            sys_cons = psutil.net_connections(kind=kind)
+        except psutil.AccessDenied:
+            # On OSX, system-wide connections are retrieved by iterating
+            # over all processes
+            if OSX:
+                return
+            else:
+                raise
+        # Filter for this proc PID and exlucde PIDs from the tuple.
+        sys_cons = [c[:-1] for c in sys_cons if c.pid == pid]
+        sys_cons.sort()
+        proc_cons.sort()
+        self.assertEqual(proc_cons, sys_cons)
+
+
+# =====================================================================
+# --- Test unconnected sockets
+# =====================================================================
+
+
+class TestUnconnectedSockets(Base, unittest.TestCase):
+    """Tests sockets which are open but not connected to anything."""
+
+    def test_tcp_v4(self):
+        addr = ("127.0.0.1", get_free_port())
+        with closing(bind_socket(AF_INET, SOCK_STREAM, addr=addr)) as sock:
+            conn = self.check_socket(sock)
+            assert not conn.raddr
+            self.assertEqual(conn.status, psutil.CONN_LISTEN)
+
+    @unittest.skipIf(not supports_ipv6(), "IPv6 not supported")
+    def test_tcp_v6(self):
+        addr = ("::1", get_free_port())
+        with closing(bind_socket(AF_INET6, SOCK_STREAM, addr=addr)) as sock:
+            conn = self.check_socket(sock)
+            assert not conn.raddr
+            self.assertEqual(conn.status, psutil.CONN_LISTEN)
+
+    def test_udp_v4(self):
+        addr = ("127.0.0.1", get_free_port())
+        with closing(bind_socket(AF_INET, SOCK_DGRAM, addr=addr)) as sock:
+            conn = self.check_socket(sock)
+            assert not conn.raddr
+            self.assertEqual(conn.status, psutil.CONN_NONE)
+
+    @unittest.skipIf(not supports_ipv6(), "IPv6 not supported")
+    def test_udp_v6(self):
+        addr = ("::1", get_free_port())
+        with closing(bind_socket(AF_INET6, SOCK_DGRAM, addr=addr)) as sock:
+            conn = self.check_socket(sock)
+            assert not conn.raddr
+            self.assertEqual(conn.status, psutil.CONN_NONE)
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_unix_tcp(self):
+        with unix_socket_path() as name:
+            with closing(bind_unix_socket(name, type=SOCK_STREAM)) as sock:
+                conn = self.check_socket(sock)
+                assert not conn.raddr
+                self.assertEqual(conn.status, psutil.CONN_NONE)
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_unix_udp(self):
+        with unix_socket_path() as name:
+            with closing(bind_unix_socket(name, type=SOCK_STREAM)) as sock:
+                conn = self.check_socket(sock)
+                assert not conn.raddr
+                self.assertEqual(conn.status, psutil.CONN_NONE)
+
+
+# =====================================================================
+# --- Test connected sockets
+# =====================================================================
+
+
+class TestConnectedSocketPairs(Base, unittest.TestCase):
+    """Test socket pairs which are are actually connected to
+    each other.
+    """
+
+    # On SunOS, even after we close() it, the server socket stays around
+    # in TIME_WAIT state.
+    @unittest.skipIf(SUNOS, "unreliable on SUONS")
+    def test_tcp(self):
+        addr = ("127.0.0.1", get_free_port())
+        assert not thisproc.connections(kind='tcp4')
+        server, client = tcp_socketpair(AF_INET, addr=addr)
+        try:
+            cons = thisproc.connections(kind='tcp4')
+            self.assertEqual(len(cons), 2)
+            self.assertEqual(cons[0].status, psutil.CONN_ESTABLISHED)
+            self.assertEqual(cons[1].status, psutil.CONN_ESTABLISHED)
+            # May not be fast enough to change state so it stays
+            # commenteed.
+            # client.close()
+            # cons = thisproc.connections(kind='all')
+            # self.assertEqual(len(cons), 1)
+            # self.assertEqual(cons[0].status, psutil.CONN_CLOSE_WAIT)
+        finally:
+            server.close()
+            client.close()
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_unix(self):
+        with unix_socket_path() as name:
+            server, client = unix_socketpair(name)
+            try:
+                cons = thisproc.connections(kind='unix')
+                assert not (cons[0].laddr and cons[0].raddr)
+                assert not (cons[1].laddr and cons[1].raddr)
+                if NETBSD:
+                    # On NetBSD creating a UNIX socket will cause
+                    # a UNIX connection to  /var/run/log.
+                    cons = [c for c in cons if c.raddr != '/var/run/log']
+                self.assertEqual(len(cons), 2)
+                if LINUX or FREEBSD or SUNOS:
+                    # remote path is never set
+                    self.assertEqual(cons[0].raddr, "")
+                    self.assertEqual(cons[1].raddr, "")
+                    # one local address should though
+                    self.assertEqual(name, cons[0].laddr or cons[1].laddr)
+                elif OPENBSD:
+                    # No addresses whatsoever here.
+                    for addr in (cons[0].laddr, cons[0].raddr,
+                                 cons[1].laddr, cons[1].raddr):
+                        self.assertEqual(addr, "")
+                else:
+                    # On other systems either the laddr or raddr
+                    # of both peers are set.
+                    self.assertEqual(cons[0].laddr or cons[1].laddr, name)
+                    self.assertEqual(cons[0].raddr or cons[1].raddr, name)
+            finally:
+                server.close()
+                client.close()
+
+    @skip_on_access_denied(only_if=OSX)
+    def test_combos(self):
+        def check_conn(proc, conn, family, type, laddr, raddr, status, kinds):
+            all_kinds = ("all", "inet", "inet4", "inet6", "tcp", "tcp4",
+                         "tcp6", "udp", "udp4", "udp6")
+            check_connection_ntuple(conn)
+            self.assertEqual(conn.family, family)
+            self.assertEqual(conn.type, type)
+            self.assertEqual(conn.laddr, laddr)
+            self.assertEqual(conn.raddr, raddr)
+            self.assertEqual(conn.status, status)
+            for kind in all_kinds:
+                cons = proc.connections(kind=kind)
+                if kind in kinds:
+                    assert cons
+                else:
+                    assert not cons, cons
+            # compare against system-wide connections
+            # XXX Solaris can't retrieve system-wide UNIX
+            # sockets.
+            if HAS_CONNECTIONS_UNIX:
+                self.compare_procsys_connections(proc.pid, [conn])
+
+        tcp_template = textwrap.dedent("""
+            import socket, time
+            s = socket.socket($family, socket.SOCK_STREAM)
+            s.bind(('$addr', 0))
+            s.listen(1)
+            with open('$testfn', 'w') as f:
+                f.write(str(s.getsockname()[:2]))
+            time.sleep(60)
+        """)
+
+        udp_template = textwrap.dedent("""
+            import socket, time
+            s = socket.socket($family, socket.SOCK_DGRAM)
+            s.bind(('$addr', 0))
+            with open('$testfn', 'w') as f:
+                f.write(str(s.getsockname()[:2]))
+            time.sleep(60)
+        """)
+
+        from string import Template
+        testfile = os.path.basename(TESTFN)
+        tcp4_template = Template(tcp_template).substitute(
+            family=int(AF_INET), addr="127.0.0.1", testfn=testfile)
+        udp4_template = Template(udp_template).substitute(
+            family=int(AF_INET), addr="127.0.0.1", testfn=testfile)
+        tcp6_template = Template(tcp_template).substitute(
+            family=int(AF_INET6), addr="::1", testfn=testfile)
+        udp6_template = Template(udp_template).substitute(
+            family=int(AF_INET6), addr="::1", testfn=testfile)
+
+        # launch various subprocess instantiating a socket of various
+        # families and types to enrich psutil results
+        tcp4_proc = pyrun(tcp4_template)
+        tcp4_addr = eval(wait_for_file(testfile))
+        udp4_proc = pyrun(udp4_template)
+        udp4_addr = eval(wait_for_file(testfile))
+        if supports_ipv6():
+            tcp6_proc = pyrun(tcp6_template)
+            tcp6_addr = eval(wait_for_file(testfile))
+            udp6_proc = pyrun(udp6_template)
+            udp6_addr = eval(wait_for_file(testfile))
+        else:
+            tcp6_proc = None
+            udp6_proc = None
+            tcp6_addr = None
+            udp6_addr = None
+
+        for p in thisproc.children():
+            cons = p.connections()
+            self.assertEqual(len(cons), 1)
+            for conn in cons:
+                # TCP v4
+                if p.pid == tcp4_proc.pid:
+                    check_conn(p, conn, AF_INET, SOCK_STREAM, tcp4_addr, (),
+                               psutil.CONN_LISTEN,
+                               ("all", "inet", "inet4", "tcp", "tcp4"))
+                # UDP v4
+                elif p.pid == udp4_proc.pid:
+                    check_conn(p, conn, AF_INET, SOCK_DGRAM, udp4_addr, (),
+                               psutil.CONN_NONE,
+                               ("all", "inet", "inet4", "udp", "udp4"))
+                # TCP v6
+                elif p.pid == getattr(tcp6_proc, "pid", None):
+                    check_conn(p, conn, AF_INET6, SOCK_STREAM, tcp6_addr, (),
+                               psutil.CONN_LISTEN,
+                               ("all", "inet", "inet6", "tcp", "tcp6"))
+                # UDP v6
+                elif p.pid == getattr(udp6_proc, "pid", None):
+                    check_conn(p, conn, AF_INET6, SOCK_DGRAM, udp6_addr, (),
+                               psutil.CONN_NONE,
+                               ("all", "inet", "inet6", "udp", "udp6"))
+
+        # err
+        self.assertRaises(ValueError, p.connections, kind='???')
+
+    def test_multi_sockets_filtering(self):
+        with create_sockets() as socks:
+            cons = thisproc.connections(kind='all')
+            self.assertEqual(len(cons), len(socks))
+            # tcp
+            cons = thisproc.connections(kind='tcp')
+            self.assertEqual(len(cons), 2 if supports_ipv6() else 1)
+            for conn in cons:
+                self.assertIn(conn.family, (AF_INET, AF_INET6))
+                self.assertEqual(conn.type, SOCK_STREAM)
+            # tcp4
+            cons = thisproc.connections(kind='tcp4')
+            self.assertEqual(len(cons), 1)
+            self.assertEqual(cons[0].family, AF_INET)
+            self.assertEqual(cons[0].type, SOCK_STREAM)
+            # tcp6
+            if supports_ipv6():
+                cons = thisproc.connections(kind='tcp6')
+                self.assertEqual(len(cons), 1)
+                self.assertEqual(cons[0].family, AF_INET6)
+                self.assertEqual(cons[0].type, SOCK_STREAM)
+            # udp
+            cons = thisproc.connections(kind='udp')
+            self.assertEqual(len(cons), 2 if supports_ipv6() else 1)
+            for conn in cons:
+                self.assertIn(conn.family, (AF_INET, AF_INET6))
+                self.assertEqual(conn.type, SOCK_DGRAM)
+            # udp4
+            cons = thisproc.connections(kind='udp4')
+            self.assertEqual(len(cons), 1)
+            self.assertEqual(cons[0].family, AF_INET)
+            self.assertEqual(cons[0].type, SOCK_DGRAM)
+            # udp6
+            if supports_ipv6():
+                cons = thisproc.connections(kind='udp6')
+                self.assertEqual(len(cons), 1)
+                self.assertEqual(cons[0].family, AF_INET6)
+                self.assertEqual(cons[0].type, SOCK_DGRAM)
+            # inet
+            cons = thisproc.connections(kind='inet')
+            self.assertEqual(len(cons), 4 if supports_ipv6() else 2)
+            for conn in cons:
+                self.assertIn(conn.family, (AF_INET, AF_INET6))
+                self.assertIn(conn.type, (SOCK_STREAM, SOCK_DGRAM))
+            # inet6
+            if supports_ipv6():
+                cons = thisproc.connections(kind='inet6')
+                self.assertEqual(len(cons), 2)
+                for conn in cons:
+                    self.assertEqual(conn.family, AF_INET6)
+                    self.assertIn(conn.type, (SOCK_STREAM, SOCK_DGRAM))
+            # unix
+            if HAS_CONNECTIONS_UNIX:
+                cons = thisproc.connections(kind='unix')
+                self.assertEqual(len(cons), 3)
+                for conn in cons:
+                    self.assertEqual(conn.family, AF_UNIX)
+                    self.assertIn(conn.type, (SOCK_STREAM, SOCK_DGRAM))
+
+
+# =====================================================================
+# --- Miscellaneous tests
+# =====================================================================
+
+
+class TestSystemWideConnections(Base, unittest.TestCase):
+    """Tests for net_connections()."""
+
+    @skip_on_access_denied()
+    def test_it(self):
+        def check(cons, families, types_):
+            AF_UNIX = getattr(socket, 'AF_UNIX', object())
+            for conn in cons:
+                self.assertIn(conn.family, families, msg=conn)
+                if conn.family != AF_UNIX:
+                    self.assertIn(conn.type, types_, msg=conn)
+                check_connection_ntuple(conn)
+
+        with create_sockets():
+            from psutil._common import conn_tmap
+            for kind, groups in conn_tmap.items():
+                # XXX: SunOS does not retrieve UNIX sockets.
+                if kind == 'unix' and not HAS_CONNECTIONS_UNIX:
+                    continue
+                families, types_ = groups
+                cons = psutil.net_connections(kind)
+                self.assertEqual(len(cons), len(set(cons)))
+                check(cons, families, types_)
+
+            self.assertRaises(ValueError, psutil.net_connections, kind='???')
+
+    @skip_on_access_denied()
+    def test_multi_socks(self):
+        with create_sockets() as socks:
+            cons = [x for x in psutil.net_connections(kind='all')
+                    if x.pid == os.getpid()]
+            self.assertEqual(len(cons), len(socks))
+
+    @skip_on_access_denied()
+    # See: https://travis-ci.org/giampaolo/psutil/jobs/237566297
+    @unittest.skipIf(OSX and TRAVIS, "unreliable on OSX + TRAVIS")
+    def test_multi_sockets_procs(self):
+        # Creates multiple sub processes, each creating different
+        # sockets. For each process check that proc.connections()
+        # and net_connections() return the same results.
+        # This is done mainly to check whether net_connections()'s
+        # pid is properly set, see:
+        # https://github.com/giampaolo/psutil/issues/1013
+        with create_sockets() as socks:
+            expected = len(socks)
+        pids = []
+        times = 10
+        for i in range(times):
+            fname = os.path.realpath(TESTFN) + str(i)
+            src = textwrap.dedent("""\
+                import time, os
+                from psutil.tests import create_sockets
+                with create_sockets():
+                    with open('%s', 'w') as f:
+                        f.write(str(os.getpid()))
+                    time.sleep(60)
+                """ % fname)
+            sproc = pyrun(src)
+            pids.append(sproc.pid)
+            self.addCleanup(safe_rmpath, fname)
+
+        # sync
+        for i in range(times):
+            fname = TESTFN + str(i)
+            wait_for_file(fname)
+
+        syscons = [x for x in psutil.net_connections(kind='all') if x.pid
+                   in pids]
+        for pid in pids:
+            self.assertEqual(len([x for x in syscons if x.pid == pid]),
+                             expected)
+            p = psutil.Process(pid)
+            self.assertEqual(len(p.connections('all')), expected)
+
+
+# =====================================================================
+# --- Miscellaneous tests
+# =====================================================================
+
+
+class TestMisc(unittest.TestCase):
+
+    def test_connection_constants(self):
+        ints = []
+        strs = []
+        for name in dir(psutil):
+            if name.startswith('CONN_'):
+                num = getattr(psutil, name)
+                str_ = str(num)
+                assert str_.isupper(), str_
+                self.assertNotIn(str, strs)
+                self.assertNotIn(num, ints)
+                ints.append(num)
+                strs.append(str_)
+        if SUNOS:
+            psutil.CONN_IDLE
+            psutil.CONN_BOUND
+        if WINDOWS:
+            psutil.CONN_DELETE_TCB
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_contracts.py b/psutil/tests/test_contracts.py
new file mode 100755
index 00000000..0dfb3e2a
--- /dev/null
+++ b/psutil/tests/test_contracts.py
@@ -0,0 +1,650 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Contracts tests. These tests mainly check API sanity in terms of
+returned types and APIs availability.
+Some of these are duplicates of tests test_system.py and test_process.py
+"""
+
+import errno
+import os
+import stat
+import time
+import traceback
+import warnings
+from contextlib import closing
+
+from psutil import AIX
+from psutil import BSD
+from psutil import FREEBSD
+from psutil import LINUX
+from psutil import NETBSD
+from psutil import OPENBSD
+from psutil import OSX
+from psutil import POSIX
+from psutil import SUNOS
+from psutil import WINDOWS
+from psutil._compat import long
+from psutil.tests import bind_unix_socket
+from psutil.tests import check_connection_ntuple
+from psutil.tests import get_kernel_version
+from psutil.tests import HAS_CONNECTIONS_UNIX
+from psutil.tests import HAS_RLIMIT
+from psutil.tests import HAS_SENSORS_FANS
+from psutil.tests import HAS_SENSORS_TEMPERATURES
+from psutil.tests import is_namedtuple
+from psutil.tests import run_test_module_by_name
+from psutil.tests import safe_rmpath
+from psutil.tests import skip_on_access_denied
+from psutil.tests import TESTFN
+from psutil.tests import unittest
+from psutil.tests import unix_socket_path
+from psutil.tests import VALID_PROC_STATUSES
+from psutil.tests import warn
+import psutil
+
+
+# ===================================================================
+# --- APIs availability
+# ===================================================================
+
+
+class TestAvailability(unittest.TestCase):
+    """Make sure code reflects what doc promises in terms of APIs
+    availability.
+    """
+
+    def test_cpu_affinity(self):
+        hasit = LINUX or WINDOWS or FREEBSD
+        self.assertEqual(hasattr(psutil.Process, "cpu_affinity"), hasit)
+
+    def test_win_service(self):
+        self.assertEqual(hasattr(psutil, "win_service_iter"), WINDOWS)
+        self.assertEqual(hasattr(psutil, "win_service_get"), WINDOWS)
+
+    def test_PROCFS_PATH(self):
+        self.assertEqual(hasattr(psutil, "PROCFS_PATH"),
+                         LINUX or SUNOS or AIX)
+
+    def test_win_priority(self):
+        ae = self.assertEqual
+        ae(hasattr(psutil, "ABOVE_NORMAL_PRIORITY_CLASS"), WINDOWS)
+        ae(hasattr(psutil, "BELOW_NORMAL_PRIORITY_CLASS"), WINDOWS)
+        ae(hasattr(psutil, "HIGH_PRIORITY_CLASS"), WINDOWS)
+        ae(hasattr(psutil, "IDLE_PRIORITY_CLASS"), WINDOWS)
+        ae(hasattr(psutil, "NORMAL_PRIORITY_CLASS"), WINDOWS)
+        ae(hasattr(psutil, "REALTIME_PRIORITY_CLASS"), WINDOWS)
+
+    def test_linux_ioprio(self):
+        ae = self.assertEqual
+        ae(hasattr(psutil, "IOPRIO_CLASS_NONE"), LINUX)
+        ae(hasattr(psutil, "IOPRIO_CLASS_RT"), LINUX)
+        ae(hasattr(psutil, "IOPRIO_CLASS_BE"), LINUX)
+        ae(hasattr(psutil, "IOPRIO_CLASS_IDLE"), LINUX)
+
+    def test_linux_rlimit(self):
+        ae = self.assertEqual
+        hasit = LINUX and get_kernel_version() >= (2, 6, 36)
+        ae(hasattr(psutil.Process, "rlimit"), hasit)
+        ae(hasattr(psutil, "RLIM_INFINITY"), hasit)
+        ae(hasattr(psutil, "RLIMIT_AS"), hasit)
+        ae(hasattr(psutil, "RLIMIT_CORE"), hasit)
+        ae(hasattr(psutil, "RLIMIT_CPU"), hasit)
+        ae(hasattr(psutil, "RLIMIT_DATA"), hasit)
+        ae(hasattr(psutil, "RLIMIT_FSIZE"), hasit)
+        ae(hasattr(psutil, "RLIMIT_LOCKS"), hasit)
+        ae(hasattr(psutil, "RLIMIT_MEMLOCK"), hasit)
+        ae(hasattr(psutil, "RLIMIT_NOFILE"), hasit)
+        ae(hasattr(psutil, "RLIMIT_NPROC"), hasit)
+        ae(hasattr(psutil, "RLIMIT_RSS"), hasit)
+        ae(hasattr(psutil, "RLIMIT_STACK"), hasit)
+
+        hasit = LINUX and get_kernel_version() >= (3, 0)
+        ae(hasattr(psutil, "RLIMIT_MSGQUEUE"), hasit)
+        ae(hasattr(psutil, "RLIMIT_NICE"), hasit)
+        ae(hasattr(psutil, "RLIMIT_RTPRIO"), hasit)
+        ae(hasattr(psutil, "RLIMIT_RTTIME"), hasit)
+        ae(hasattr(psutil, "RLIMIT_SIGPENDING"), hasit)
+
+    def test_cpu_freq(self):
+        linux = (LINUX and
+                 (os.path.exists("/sys/devices/system/cpu/cpufreq") or
+                  os.path.exists("/sys/devices/system/cpu/cpu0/cpufreq")))
+        self.assertEqual(hasattr(psutil, "cpu_freq"), linux or OSX or WINDOWS)
+
+    def test_sensors_temperatures(self):
+        self.assertEqual(hasattr(psutil, "sensors_temperatures"), LINUX)
+
+    def test_sensors_fans(self):
+        self.assertEqual(hasattr(psutil, "sensors_fans"), LINUX)
+
+    def test_battery(self):
+        self.assertEqual(hasattr(psutil, "sensors_battery"),
+                         LINUX or WINDOWS or FREEBSD or OSX)
+
+    def test_proc_environ(self):
+        self.assertEqual(hasattr(psutil.Process, "environ"),
+                         LINUX or OSX or WINDOWS)
+
+    def test_proc_uids(self):
+        self.assertEqual(hasattr(psutil.Process, "uids"), POSIX)
+
+    def test_proc_gids(self):
+        self.assertEqual(hasattr(psutil.Process, "uids"), POSIX)
+
+    def test_proc_terminal(self):
+        self.assertEqual(hasattr(psutil.Process, "terminal"), POSIX)
+
+    def test_proc_ionice(self):
+        self.assertEqual(hasattr(psutil.Process, "ionice"), LINUX or WINDOWS)
+
+    def test_proc_rlimit(self):
+        self.assertEqual(hasattr(psutil.Process, "rlimit"), LINUX)
+
+    def test_proc_io_counters(self):
+        hasit = hasattr(psutil.Process, "io_counters")
+        self.assertEqual(hasit, False if OSX or SUNOS else True)
+
+    def test_proc_num_fds(self):
+        self.assertEqual(hasattr(psutil.Process, "num_fds"), POSIX)
+
+    def test_proc_num_handles(self):
+        self.assertEqual(hasattr(psutil.Process, "num_handles"), WINDOWS)
+
+    def test_proc_cpu_affinity(self):
+        self.assertEqual(hasattr(psutil.Process, "cpu_affinity"),
+                         LINUX or WINDOWS or FREEBSD)
+
+    def test_proc_cpu_num(self):
+        self.assertEqual(hasattr(psutil.Process, "cpu_num"),
+                         LINUX or FREEBSD or SUNOS)
+
+    def test_proc_memory_maps(self):
+        hasit = hasattr(psutil.Process, "memory_maps")
+        self.assertEqual(hasit, False if OPENBSD or NETBSD or AIX else True)
+
+
+# ===================================================================
+# --- Test deprecations
+# ===================================================================
+
+
+class TestDeprecations(unittest.TestCase):
+
+    def test_memory_info_ex(self):
+        with warnings.catch_warnings(record=True) as ws:
+            psutil.Process().memory_info_ex()
+        w = ws[0]
+        self.assertIsInstance(w.category(), FutureWarning)
+        self.assertIn("memory_info_ex() is deprecated", str(w.message))
+        self.assertIn("use memory_info() instead", str(w.message))
+
+
+# ===================================================================
+# --- System API types
+# ===================================================================
+
+
+class TestSystem(unittest.TestCase):
+    """Check the return types of system related APIs.
+    Mainly we want to test we never return unicode on Python 2, see:
+    https://github.com/giampaolo/psutil/issues/1039
+    """
+
+    @classmethod
+    def setUpClass(cls):
+        cls.proc = psutil.Process()
+
+    def tearDown(self):
+        safe_rmpath(TESTFN)
+
+    def test_cpu_times(self):
+        # Duplicate of test_system.py. Keep it anyway.
+        ret = psutil.cpu_times()
+        assert is_namedtuple(ret)
+        for n in ret:
+            self.assertIsInstance(n, float)
+            self.assertGreaterEqual(n, 0)
+
+    def test_io_counters(self):
+        # Duplicate of test_system.py. Keep it anyway.
+        for k in psutil.disk_io_counters(perdisk=True):
+            self.assertIsInstance(k, str)
+
+    def test_disk_partitions(self):
+        # Duplicate of test_system.py. Keep it anyway.
+        for disk in psutil.disk_partitions():
+            self.assertIsInstance(disk.device, str)
+            self.assertIsInstance(disk.mountpoint, str)
+            self.assertIsInstance(disk.fstype, str)
+            self.assertIsInstance(disk.opts, str)
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    @unittest.skipIf(not HAS_CONNECTIONS_UNIX, "can't list UNIX sockets")
+    @skip_on_access_denied(only_if=OSX)
+    def test_net_connections(self):
+        with unix_socket_path() as name:
+            with closing(bind_unix_socket(name)):
+                cons = psutil.net_connections(kind='unix')
+                assert cons
+                for conn in cons:
+                    self.assertIsInstance(conn.laddr, str)
+
+    def test_net_if_addrs(self):
+        # Duplicate of test_system.py. Keep it anyway.
+        for ifname, addrs in psutil.net_if_addrs().items():
+            self.assertIsInstance(ifname, str)
+            for addr in addrs:
+                self.assertIsInstance(addr.address, str)
+                self.assertIsInstance(addr.netmask, (str, type(None)))
+                self.assertIsInstance(addr.broadcast, (str, type(None)))
+
+    def test_net_if_stats(self):
+        # Duplicate of test_system.py. Keep it anyway.
+        for ifname, _ in psutil.net_if_stats().items():
+            self.assertIsInstance(ifname, str)
+
+    def test_net_io_counters(self):
+        # Duplicate of test_system.py. Keep it anyway.
+        for ifname, _ in psutil.net_io_counters(pernic=True).items():
+            self.assertIsInstance(ifname, str)
+
+    @unittest.skipIf(not HAS_SENSORS_FANS, "not supported")
+    def test_sensors_fans(self):
+        # Duplicate of test_system.py. Keep it anyway.
+        for name, units in psutil.sensors_fans().items():
+            self.assertIsInstance(name, str)
+            for unit in units:
+                self.assertIsInstance(unit.label, str)
+
+    @unittest.skipIf(not HAS_SENSORS_TEMPERATURES, "not supported")
+    def test_sensors_temperatures(self):
+        # Duplicate of test_system.py. Keep it anyway.
+        for name, units in psutil.sensors_temperatures().items():
+            self.assertIsInstance(name, str)
+            for unit in units:
+                self.assertIsInstance(unit.label, str)
+
+    def test_users(self):
+        # Duplicate of test_system.py. Keep it anyway.
+        for user in psutil.users():
+            self.assertIsInstance(user.name, str)
+            self.assertIsInstance(user.terminal, (str, type(None)))
+            self.assertIsInstance(user.host, (str, type(None)))
+            self.assertIsInstance(user.pid, (int, type(None)))
+
+
+# ===================================================================
+# --- Featch all processes test
+# ===================================================================
+
+
+class TestFetchAllProcesses(unittest.TestCase):
+    """Test which iterates over all running processes and performs
+    some sanity checks against Process API's returned values.
+    """
+
+    def setUp(self):
+        if POSIX:
+            import pwd
+            import grp
+            users = pwd.getpwall()
+            groups = grp.getgrall()
+            self.all_uids = set([x.pw_uid for x in users])
+            self.all_usernames = set([x.pw_name for x in users])
+            self.all_gids = set([x.gr_gid for x in groups])
+
+    def test_fetch_all(self):
+        valid_procs = 0
+        excluded_names = set([
+            'send_signal', 'suspend', 'resume', 'terminate', 'kill', 'wait',
+            'as_dict', 'parent', 'children', 'memory_info_ex', 'oneshot',
+        ])
+        if LINUX and not HAS_RLIMIT:
+            excluded_names.add('rlimit')
+        attrs = []
+        for name in dir(psutil.Process):
+            if name.startswith("_"):
+                continue
+            if name in excluded_names:
+                continue
+            attrs.append(name)
+
+        default = object()
+        failures = []
+        for p in psutil.process_iter():
+            with p.oneshot():
+                for name in attrs:
+                    ret = default
+                    try:
+                        args = ()
+                        kwargs = {}
+                        attr = getattr(p, name, None)
+                        if attr is not None and callable(attr):
+                            if name == 'rlimit':
+                                args = (psutil.RLIMIT_NOFILE,)
+                            elif name == 'memory_maps':
+                                kwargs = {'grouped': False}
+                            ret = attr(*args, **kwargs)
+                        else:
+                            ret = attr
+                        valid_procs += 1
+                    except NotImplementedError:
+                        msg = "%r was skipped because not implemented" % (
+                            self.__class__.__name__ + '.test_' + name)
+                        warn(msg)
+                    except (psutil.NoSuchProcess, psutil.AccessDenied) as err:
+                        self.assertEqual(err.pid, p.pid)
+                        if err.name:
+                            # make sure exception's name attr is set
+                            # with the actual process name
+                            self.assertEqual(err.name, p.name())
+                        assert str(err)
+                        assert err.msg
+                    except Exception as err:
+                        s = '\n' + '=' * 70 + '\n'
+                        s += "FAIL: test_%s (proc=%s" % (name, p)
+                        if ret != default:
+                            s += ", ret=%s)" % repr(ret)
+                        s += ')\n'
+                        s += '-' * 70
+                        s += "\n%s" % traceback.format_exc()
+                        s = "\n".join((" " * 4) + i for i in s.splitlines())
+                        s += '\n'
+                        failures.append(s)
+                        break
+                    else:
+                        if ret not in (0, 0.0, [], None, '', {}):
+                            assert ret, ret
+                        meth = getattr(self, name)
+                        meth(ret, p)
+
+        if failures:
+            self.fail(''.join(failures))
+
+        # we should always have a non-empty list, not including PID 0 etc.
+        # special cases.
+        assert valid_procs
+
+    def cmdline(self, ret, proc):
+        self.assertIsInstance(ret, list)
+        for part in ret:
+            self.assertIsInstance(part, str)
+
+    def exe(self, ret, proc):
+        self.assertIsInstance(ret, (str, type(None)))
+        if not ret:
+            self.assertEqual(ret, '')
+        else:
+            assert os.path.isabs(ret), ret
+            # Note: os.stat() may return False even if the file is there
+            # hence we skip the test, see:
+            # http://stackoverflow.com/questions/3112546/os-path-exists-lies
+            if POSIX and os.path.isfile(ret):
+                if hasattr(os, 'access') and hasattr(os, "X_OK"):
+                    # XXX may fail on OSX
+                    assert os.access(ret, os.X_OK)
+
+    def pid(self, ret, proc):
+        self.assertIsInstance(ret, int)
+        self.assertGreaterEqual(ret, 0)
+
+    def ppid(self, ret, proc):
+        self.assertIsInstance(ret, (int, long))
+        self.assertGreaterEqual(ret, 0)
+
+    def name(self, ret, proc):
+        self.assertIsInstance(ret, str)
+        # on AIX, "<exiting>" processes don't have names
+        if not AIX:
+            assert ret
+
+    def create_time(self, ret, proc):
+        self.assertIsInstance(ret, float)
+        try:
+            self.assertGreaterEqual(ret, 0)
+        except AssertionError:
+            # XXX
+            if OPENBSD and proc.status() == psutil.STATUS_ZOMBIE:
+                pass
+            else:
+                raise
+        # this can't be taken for granted on all platforms
+        # self.assertGreaterEqual(ret, psutil.boot_time())
+        # make sure returned value can be pretty printed
+        # with strftime
+        time.strftime("%Y %m %d %H:%M:%S", time.localtime(ret))
+
+    def uids(self, ret, proc):
+        assert is_namedtuple(ret)
+        for uid in ret:
+            self.assertIsInstance(uid, int)
+            self.assertGreaterEqual(uid, 0)
+            self.assertIn(uid, self.all_uids)
+
+    def gids(self, ret, proc):
+        assert is_namedtuple(ret)
+        # note: testing all gids as above seems not to be reliable for
+        # gid == 30 (nodoby); not sure why.
+        for gid in ret:
+            self.assertIsInstance(gid, int)
+            if not OSX and not NETBSD:
+                self.assertGreaterEqual(gid, 0)
+                self.assertIn(gid, self.all_gids)
+
+    def username(self, ret, proc):
+        self.assertIsInstance(ret, str)
+        assert ret
+        if POSIX:
+            self.assertIn(ret, self.all_usernames)
+
+    def status(self, ret, proc):
+        self.assertIsInstance(ret, str)
+        assert ret
+        self.assertNotEqual(ret, '?')  # XXX
+        self.assertIn(ret, VALID_PROC_STATUSES)
+
+    def io_counters(self, ret, proc):
+        assert is_namedtuple(ret)
+        for field in ret:
+            self.assertIsInstance(field, (int, long))
+            if field != -1:
+                self.assertGreaterEqual(field, 0)
+
+    def ionice(self, ret, proc):
+        if POSIX:
+            assert is_namedtuple(ret)
+            for field in ret:
+                self.assertIsInstance(field, int)
+        if LINUX:
+            self.assertGreaterEqual(ret.ioclass, 0)
+            self.assertGreaterEqual(ret.value, 0)
+        else:
+            self.assertGreaterEqual(ret, 0)
+            self.assertIn(ret, (0, 1, 2))
+
+    def num_threads(self, ret, proc):
+        self.assertIsInstance(ret, int)
+        self.assertGreaterEqual(ret, 1)
+
+    def threads(self, ret, proc):
+        self.assertIsInstance(ret, list)
+        for t in ret:
+            assert is_namedtuple(t)
+            self.assertGreaterEqual(t.id, 0)
+            self.assertGreaterEqual(t.user_time, 0)
+            self.assertGreaterEqual(t.system_time, 0)
+            for field in t:
+                self.assertIsInstance(field, (int, float))
+
+    def cpu_times(self, ret, proc):
+        assert is_namedtuple(ret)
+        for n in ret:
+            self.assertIsInstance(n, float)
+            self.assertGreaterEqual(n, 0)
+        # TODO: check ntuple fields
+
+    def cpu_percent(self, ret, proc):
+        self.assertIsInstance(ret, float)
+        assert 0.0 <= ret <= 100.0, ret
+
+    def cpu_num(self, ret, proc):
+        self.assertIsInstance(ret, int)
+        if FREEBSD and ret == -1:
+            return
+        self.assertGreaterEqual(ret, 0)
+        if psutil.cpu_count() == 1:
+            self.assertEqual(ret, 0)
+        self.assertIn(ret, list(range(psutil.cpu_count())))
+
+    def memory_info(self, ret, proc):
+        assert is_namedtuple(ret)
+        for value in ret:
+            self.assertIsInstance(value, (int, long))
+            self.assertGreaterEqual(value, 0)
+        if POSIX and not AIX and ret.vms != 0:
+            # VMS is always supposed to be the highest
+            for name in ret._fields:
+                if name != 'vms':
+                    value = getattr(ret, name)
+                    self.assertGreater(ret.vms, value, msg=ret)
+        elif WINDOWS:
+            self.assertGreaterEqual(ret.peak_wset, ret.wset)
+            self.assertGreaterEqual(ret.peak_paged_pool, ret.paged_pool)
+            self.assertGreaterEqual(ret.peak_nonpaged_pool, ret.nonpaged_pool)
+            self.assertGreaterEqual(ret.peak_pagefile, ret.pagefile)
+
+    def memory_full_info(self, ret, proc):
+        assert is_namedtuple(ret)
+        total = psutil.virtual_memory().total
+        for name in ret._fields:
+            value = getattr(ret, name)
+            self.assertIsInstance(value, (int, long))
+            self.assertGreaterEqual(value, 0, msg=(name, value))
+            self.assertLessEqual(value, total, msg=(name, value, total))
+
+        if LINUX:
+            self.assertGreaterEqual(ret.pss, ret.uss)
+
+    def open_files(self, ret, proc):
+        self.assertIsInstance(ret, list)
+        for f in ret:
+            self.assertIsInstance(f.fd, int)
+            self.assertIsInstance(f.path, str)
+            if WINDOWS:
+                self.assertEqual(f.fd, -1)
+            elif LINUX:
+                self.assertIsInstance(f.position, int)
+                self.assertIsInstance(f.mode, str)
+                self.assertIsInstance(f.flags, int)
+                self.assertGreaterEqual(f.position, 0)
+                self.assertIn(f.mode, ('r', 'w', 'a', 'r+', 'a+'))
+                self.assertGreater(f.flags, 0)
+            elif BSD and not f.path:
+                # XXX see: https://github.com/giampaolo/psutil/issues/595
+                continue
+            assert os.path.isabs(f.path), f
+            assert os.path.isfile(f.path), f
+
+    def num_fds(self, ret, proc):
+        self.assertIsInstance(ret, int)
+        self.assertGreaterEqual(ret, 0)
+
+    def connections(self, ret, proc):
+        self.assertEqual(len(ret), len(set(ret)))
+        for conn in ret:
+            check_connection_ntuple(conn)
+
+    def cwd(self, ret, proc):
+        if ret:     # 'ret' can be None or empty
+            self.assertIsInstance(ret, str)
+            assert os.path.isabs(ret), ret
+            try:
+                st = os.stat(ret)
+            except OSError as err:
+                if WINDOWS and err.errno in \
+                        psutil._psplatform.ACCESS_DENIED_SET:
+                    pass
+                # directory has been removed in mean time
+                elif err.errno != errno.ENOENT:
+                    raise
+            else:
+                assert stat.S_ISDIR(st.st_mode)
+
+    def memory_percent(self, ret, proc):
+        self.assertIsInstance(ret, float)
+        assert 0 <= ret <= 100, ret
+
+    def is_running(self, ret, proc):
+        self.assertIsInstance(ret, bool)
+
+    def cpu_affinity(self, ret, proc):
+        self.assertIsInstance(ret, list)
+        assert ret != [], ret
+        cpus = range(psutil.cpu_count())
+        for n in ret:
+            self.assertIsInstance(n, int)
+            self.assertIn(n, cpus)
+
+    def terminal(self, ret, proc):
+        self.assertIsInstance(ret, (str, type(None)))
+        if ret is not None:
+            assert os.path.isabs(ret), ret
+            assert os.path.exists(ret), ret
+
+    def memory_maps(self, ret, proc):
+        for nt in ret:
+            self.assertIsInstance(nt.addr, str)
+            self.assertIsInstance(nt.perms, str)
+            self.assertIsInstance(nt.path, str)
+            for fname in nt._fields:
+                value = getattr(nt, fname)
+                if fname == 'path':
+                    if not value.startswith('['):
+                        assert os.path.isabs(nt.path), nt.path
+                        # commented as on Linux we might get
+                        # '/foo/bar (deleted)'
+                        # assert os.path.exists(nt.path), nt.path
+                elif fname in ('addr', 'perms'):
+                    assert value
+                else:
+                    self.assertIsInstance(value, (int, long))
+                    self.assertGreaterEqual(value, 0)
+
+    def num_handles(self, ret, proc):
+        self.assertIsInstance(ret, int)
+        self.assertGreaterEqual(ret, 0)
+
+    def nice(self, ret, proc):
+        self.assertIsInstance(ret, int)
+        if POSIX:
+            assert -20 <= ret <= 20, ret
+        else:
+            priorities = [getattr(psutil, x) for x in dir(psutil)
+                          if x.endswith('_PRIORITY_CLASS')]
+            self.assertIn(ret, priorities)
+
+    def num_ctx_switches(self, ret, proc):
+        assert is_namedtuple(ret)
+        for value in ret:
+            self.assertIsInstance(value, (int, long))
+            self.assertGreaterEqual(value, 0)
+
+    def rlimit(self, ret, proc):
+        self.assertIsInstance(ret, tuple)
+        self.assertEqual(len(ret), 2)
+        self.assertGreaterEqual(ret[0], -1)
+        self.assertGreaterEqual(ret[1], -1)
+
+    def environ(self, ret, proc):
+        self.assertIsInstance(ret, dict)
+        for k, v in ret.items():
+            self.assertIsInstance(k, str)
+            self.assertIsInstance(v, str)
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_linux.py b/psutil/tests/test_linux.py
new file mode 100755
index 00000000..6ba17b25
--- /dev/null
+++ b/psutil/tests/test_linux.py
@@ -0,0 +1,1910 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Linux specific tests."""
+
+from __future__ import division
+import collections
+import contextlib
+import errno
+import glob
+import io
+import os
+import pprint
+import re
+import shutil
+import socket
+import struct
+import tempfile
+import textwrap
+import time
+import warnings
+
+import psutil
+from psutil import LINUX
+from psutil._compat import PY3
+from psutil._compat import u
+from psutil.tests import call_until
+from psutil.tests import HAS_BATTERY
+from psutil.tests import HAS_CPU_FREQ
+from psutil.tests import HAS_RLIMIT
+from psutil.tests import MEMORY_TOLERANCE
+from psutil.tests import mock
+from psutil.tests import PYPY
+from psutil.tests import pyrun
+from psutil.tests import reap_children
+from psutil.tests import reload_module
+from psutil.tests import retry_before_failing
+from psutil.tests import run_test_module_by_name
+from psutil.tests import safe_rmpath
+from psutil.tests import sh
+from psutil.tests import skip_on_not_implemented
+from psutil.tests import TESTFN
+from psutil.tests import ThreadTask
+from psutil.tests import TRAVIS
+from psutil.tests import unittest
+from psutil.tests import which
+
+
+HERE = os.path.abspath(os.path.dirname(__file__))
+SIOCGIFADDR = 0x8915
+SIOCGIFCONF = 0x8912
+SIOCGIFHWADDR = 0x8927
+if LINUX:
+    SECTOR_SIZE = 512
+
+
+# =====================================================================
+# --- utils
+# =====================================================================
+
+
+def get_ipv4_address(ifname):
+    import fcntl
+    ifname = ifname[:15]
+    if PY3:
+        ifname = bytes(ifname, 'ascii')
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    with contextlib.closing(s):
+        return socket.inet_ntoa(
+            fcntl.ioctl(s.fileno(),
+                        SIOCGIFADDR,
+                        struct.pack('256s', ifname))[20:24])
+
+
+def get_mac_address(ifname):
+    import fcntl
+    ifname = ifname[:15]
+    if PY3:
+        ifname = bytes(ifname, 'ascii')
+    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    with contextlib.closing(s):
+        info = fcntl.ioctl(
+            s.fileno(), SIOCGIFHWADDR, struct.pack('256s', ifname))
+        if PY3:
+            def ord(x):
+                return x
+        else:
+            import __builtin__
+            ord = __builtin__.ord
+        return ''.join(['%02x:' % ord(char) for char in info[18:24]])[:-1]
+
+
+def free_swap():
+    """Parse 'free' cmd and return swap memory's s total, used and free
+    values.
+    """
+    out = sh('free -b')
+    lines = out.split('\n')
+    for line in lines:
+        if line.startswith('Swap'):
+            _, total, used, free = line.split()
+            nt = collections.namedtuple('free', 'total used free')
+            return nt(int(total), int(used), int(free))
+    raise ValueError(
+        "can't find 'Swap' in 'free' output:\n%s" % '\n'.join(lines))
+
+
+def free_physmem():
+    """Parse 'free' cmd and return physical memory's total, used
+    and free values.
+    """
+    # Note: free can have 2 different formats, invalidating 'shared'
+    # and 'cached' memory which may have different positions so we
+    # do not return them.
+    # https://github.com/giampaolo/psutil/issues/538#issuecomment-57059946
+    out = sh('free -b')
+    lines = out.split('\n')
+    for line in lines:
+        if line.startswith('Mem'):
+            total, used, free, shared = \
+                [int(x) for x in line.split()[1:5]]
+            nt = collections.namedtuple(
+                'free', 'total used free shared output')
+            return nt(total, used, free, shared, out)
+    raise ValueError(
+        "can't find 'Mem' in 'free' output:\n%s" % '\n'.join(lines))
+
+
+def vmstat(stat):
+    out = sh("vmstat -s")
+    for line in out.split("\n"):
+        line = line.strip()
+        if stat in line:
+            return int(line.split(' ')[0])
+    raise ValueError("can't find %r in 'vmstat' output" % stat)
+
+
+def get_free_version_info():
+    out = sh("free -V").strip()
+    return tuple(map(int, out.split()[-1].split('.')))
+
+
+# =====================================================================
+# --- system virtual memory
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestSystemVirtualMemory(unittest.TestCase):
+
+    def test_total(self):
+        # free_value = free_physmem().total
+        # psutil_value = psutil.virtual_memory().total
+        # self.assertEqual(free_value, psutil_value)
+        vmstat_value = vmstat('total memory') * 1024
+        psutil_value = psutil.virtual_memory().total
+        self.assertAlmostEqual(vmstat_value, psutil_value)
+
+    # Older versions of procps used slab memory to calculate used memory.
+    # This got changed in:
+    # https://gitlab.com/procps-ng/procps/commit/
+    #     05d751c4f076a2f0118b914c5e51cfbb4762ad8e
+    @unittest.skipIf(LINUX and get_free_version_info() < (3, 3, 12),
+                     "old free version")
+    @retry_before_failing()
+    def test_used(self):
+        free = free_physmem()
+        free_value = free.used
+        psutil_value = psutil.virtual_memory().used
+        self.assertAlmostEqual(
+            free_value, psutil_value, delta=MEMORY_TOLERANCE,
+            msg='%s %s \n%s' % (free_value, psutil_value, free.output))
+
+    @unittest.skipIf(TRAVIS, "unreliable on TRAVIS")
+    @retry_before_failing()
+    def test_free(self):
+        # _, _, free_value, _ = free_physmem()
+        # psutil_value = psutil.virtual_memory().free
+        # self.assertAlmostEqual(
+        #     free_value, psutil_value, delta=MEMORY_TOLERANCE)
+        vmstat_value = vmstat('free memory') * 1024
+        psutil_value = psutil.virtual_memory().free
+        self.assertAlmostEqual(
+            vmstat_value, psutil_value, delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_buffers(self):
+        vmstat_value = vmstat('buffer memory') * 1024
+        psutil_value = psutil.virtual_memory().buffers
+        self.assertAlmostEqual(
+            vmstat_value, psutil_value, delta=MEMORY_TOLERANCE)
+
+    # https://travis-ci.org/giampaolo/psutil/jobs/226719664
+    @unittest.skipIf(TRAVIS, "unreliable on TRAVIS")
+    @retry_before_failing()
+    def test_active(self):
+        vmstat_value = vmstat('active memory') * 1024
+        psutil_value = psutil.virtual_memory().active
+        self.assertAlmostEqual(
+            vmstat_value, psutil_value, delta=MEMORY_TOLERANCE)
+
+    # https://travis-ci.org/giampaolo/psutil/jobs/227242952
+    @unittest.skipIf(TRAVIS, "unreliable on TRAVIS")
+    @retry_before_failing()
+    def test_inactive(self):
+        vmstat_value = vmstat('inactive memory') * 1024
+        psutil_value = psutil.virtual_memory().inactive
+        self.assertAlmostEqual(
+            vmstat_value, psutil_value, delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_shared(self):
+        free = free_physmem()
+        free_value = free.shared
+        if free_value == 0:
+            raise unittest.SkipTest("free does not support 'shared' column")
+        psutil_value = psutil.virtual_memory().shared
+        self.assertAlmostEqual(
+            free_value, psutil_value, delta=MEMORY_TOLERANCE,
+            msg='%s %s \n%s' % (free_value, psutil_value, free.output))
+
+    @retry_before_failing()
+    def test_available(self):
+        # "free" output format has changed at some point:
+        # https://github.com/giampaolo/psutil/issues/538#issuecomment-147192098
+        out = sh("free -b")
+        lines = out.split('\n')
+        if 'available' not in lines[0]:
+            raise unittest.SkipTest("free does not support 'available' column")
+        else:
+            free_value = int(lines[1].split()[-1])
+            psutil_value = psutil.virtual_memory().available
+            self.assertAlmostEqual(
+                free_value, psutil_value, delta=MEMORY_TOLERANCE,
+                msg='%s %s \n%s' % (free_value, psutil_value, out))
+
+    def test_warnings_on_misses(self):
+        # Emulate a case where /proc/meminfo provides few info.
+        # psutil is supposed to set the missing fields to 0 and
+        # raise a warning.
+        def open_mock(name, *args, **kwargs):
+            if name == '/proc/meminfo':
+                return io.BytesIO(textwrap.dedent("""\
+                    Active(anon):    6145416 kB
+                    Active(file):    2950064 kB
+                    Inactive(anon):   574764 kB
+                    Inactive(file):  1567648 kB
+                    MemAvailable:         -1 kB
+                    MemFree:         2057400 kB
+                    MemTotal:       16325648 kB
+                    SReclaimable:     346648 kB
+                    """).encode())
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, create=True, side_effect=open_mock) as m:
+            with warnings.catch_warnings(record=True) as ws:
+                warnings.simplefilter("always")
+                ret = psutil.virtual_memory()
+                assert m.called
+                self.assertEqual(len(ws), 1)
+                w = ws[0]
+                assert w.filename.endswith('psutil/_pslinux.py')
+                self.assertIn(
+                    "memory stats couldn't be determined", str(w.message))
+                self.assertIn("cached", str(w.message))
+                self.assertIn("shared", str(w.message))
+                self.assertIn("active", str(w.message))
+                self.assertIn("inactive", str(w.message))
+                self.assertIn("buffers", str(w.message))
+                self.assertIn("available", str(w.message))
+                self.assertEqual(ret.cached, 0)
+                self.assertEqual(ret.active, 0)
+                self.assertEqual(ret.inactive, 0)
+                self.assertEqual(ret.shared, 0)
+                self.assertEqual(ret.buffers, 0)
+                self.assertEqual(ret.available, 0)
+
+    def test_avail_old_percent(self):
+        # Make sure that our calculation of avail mem for old kernels
+        # is off by max 10%.
+        from psutil._pslinux import calculate_avail_vmem
+        from psutil._pslinux import open_binary
+
+        mems = {}
+        with open_binary('/proc/meminfo') as f:
+            for line in f:
+                fields = line.split()
+                mems[fields[0]] = int(fields[1]) * 1024
+
+        a = calculate_avail_vmem(mems)
+        if b'MemAvailable:' in mems:
+            b = mems[b'MemAvailable:']
+            diff_percent = abs(a - b) / a * 100
+            self.assertLess(diff_percent, 10)
+
+    def test_avail_old_comes_from_kernel(self):
+        # Make sure "MemAvailable:" coluimn is used instead of relying
+        # on our internal algorithm to calculate avail mem.
+        def open_mock(name, *args, **kwargs):
+            if name == "/proc/meminfo":
+                return io.BytesIO(textwrap.dedent("""\
+                    Active:          9444728 kB
+                    Active(anon):    6145416 kB
+                    Active(file):    2950064 kB
+                    Buffers:          287952 kB
+                    Cached:          4818144 kB
+                    Inactive(file):  1578132 kB
+                    Inactive(anon):   574764 kB
+                    Inactive(file):  1567648 kB
+                    MemAvailable:    6574984 kB
+                    MemFree:         2057400 kB
+                    MemTotal:       16325648 kB
+                    Shmem:            577588 kB
+                    SReclaimable:     346648 kB
+                    """).encode())
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, create=True, side_effect=open_mock) as m:
+            with warnings.catch_warnings(record=True) as ws:
+                ret = psutil.virtual_memory()
+            assert m.called
+            self.assertEqual(ret.available, 6574984 * 1024)
+            w = ws[0]
+            self.assertIn(
+                "inactive memory stats couldn't be determined", str(w.message))
+
+    def test_avail_old_missing_fields(self):
+        # Remove Active(file), Inactive(file) and SReclaimable
+        # from /proc/meminfo and make sure the fallback is used
+        # (free + cached),
+        def open_mock(name, *args, **kwargs):
+            if name == "/proc/meminfo":
+                return io.BytesIO(textwrap.dedent("""\
+                    Active:          9444728 kB
+                    Active(anon):    6145416 kB
+                    Buffers:          287952 kB
+                    Cached:          4818144 kB
+                    Inactive(file):  1578132 kB
+                    Inactive(anon):   574764 kB
+                    MemFree:         2057400 kB
+                    MemTotal:       16325648 kB
+                    Shmem:            577588 kB
+                    """).encode())
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, create=True, side_effect=open_mock) as m:
+            with warnings.catch_warnings(record=True) as ws:
+                ret = psutil.virtual_memory()
+            assert m.called
+            self.assertEqual(ret.available, 2057400 * 1024 + 4818144 * 1024)
+            w = ws[0]
+            self.assertIn(
+                "inactive memory stats couldn't be determined", str(w.message))
+
+    def test_avail_old_missing_zoneinfo(self):
+        # Remove /proc/zoneinfo file. Make sure fallback is used
+        # (free + cached).
+        def open_mock(name, *args, **kwargs):
+            if name == "/proc/meminfo":
+                return io.BytesIO(textwrap.dedent("""\
+                    Active:          9444728 kB
+                    Active(anon):    6145416 kB
+                    Active(file):    2950064 kB
+                    Buffers:          287952 kB
+                    Cached:          4818144 kB
+                    Inactive(file):  1578132 kB
+                    Inactive(anon):   574764 kB
+                    Inactive(file):  1567648 kB
+                    MemFree:         2057400 kB
+                    MemTotal:       16325648 kB
+                    Shmem:            577588 kB
+                    SReclaimable:     346648 kB
+                    """).encode())
+            elif name == "/proc/zoneinfo":
+                raise IOError(errno.ENOENT, 'no such file or directory')
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, create=True, side_effect=open_mock) as m:
+            with warnings.catch_warnings(record=True) as ws:
+                ret = psutil.virtual_memory()
+            assert m.called
+            self.assertEqual(ret.available, 2057400 * 1024 + 4818144 * 1024)
+            w = ws[0]
+            self.assertIn(
+                "inactive memory stats couldn't be determined", str(w.message))
+
+
+# =====================================================================
+# --- system swap memory
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestSystemSwapMemory(unittest.TestCase):
+
+    @staticmethod
+    def meminfo_has_swap_info():
+        """Return True if /proc/meminfo provides swap metrics."""
+        with open("/proc/meminfo") as f:
+            data = f.read()
+        return 'SwapTotal:' in data and 'SwapFree:' in data
+
+    def test_total(self):
+        free_value = free_swap().total
+        psutil_value = psutil.swap_memory().total
+        return self.assertAlmostEqual(
+            free_value, psutil_value, delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_used(self):
+        free_value = free_swap().used
+        psutil_value = psutil.swap_memory().used
+        return self.assertAlmostEqual(
+            free_value, psutil_value, delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_free(self):
+        free_value = free_swap().free
+        psutil_value = psutil.swap_memory().free
+        return self.assertAlmostEqual(
+            free_value, psutil_value, delta=MEMORY_TOLERANCE)
+
+    def test_missing_sin_sout(self):
+        with mock.patch('psutil._pslinux.open', create=True) as m:
+            with warnings.catch_warnings(record=True) as ws:
+                warnings.simplefilter("always")
+                ret = psutil.swap_memory()
+                assert m.called
+                self.assertEqual(len(ws), 1)
+                w = ws[0]
+                assert w.filename.endswith('psutil/_pslinux.py')
+                self.assertIn(
+                    "'sin' and 'sout' swap memory stats couldn't "
+                    "be determined", str(w.message))
+                self.assertEqual(ret.sin, 0)
+                self.assertEqual(ret.sout, 0)
+
+    def test_no_vmstat_mocked(self):
+        # see https://github.com/giampaolo/psutil/issues/722
+        def open_mock(name, *args, **kwargs):
+            if name == "/proc/vmstat":
+                raise IOError(errno.ENOENT, 'no such file or directory')
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, create=True, side_effect=open_mock) as m:
+            with warnings.catch_warnings(record=True) as ws:
+                warnings.simplefilter("always")
+                ret = psutil.swap_memory()
+                assert m.called
+                self.assertEqual(len(ws), 1)
+                w = ws[0]
+                assert w.filename.endswith('psutil/_pslinux.py')
+                self.assertIn(
+                    "'sin' and 'sout' swap memory stats couldn't "
+                    "be determined and were set to 0",
+                    str(w.message))
+                self.assertEqual(ret.sin, 0)
+                self.assertEqual(ret.sout, 0)
+
+    def test_meminfo_against_sysinfo(self):
+        # Make sure the content of /proc/meminfo about swap memory
+        # matches sysinfo() syscall, see:
+        # https://github.com/giampaolo/psutil/issues/1015
+        if not self.meminfo_has_swap_info():
+            return unittest.skip("/proc/meminfo has no swap metrics")
+        with mock.patch('psutil._pslinux.cext.linux_sysinfo') as m:
+            swap = psutil.swap_memory()
+        assert not m.called
+        import psutil._psutil_linux as cext
+        _, _, _, _, total, free, unit_multiplier = cext.linux_sysinfo()
+        total *= unit_multiplier
+        free *= unit_multiplier
+        self.assertEqual(swap.total, total)
+        self.assertEqual(swap.free, free)
+
+    def test_emulate_meminfo_has_no_metrics(self):
+        # Emulate a case where /proc/meminfo provides no swap metrics
+        # in which case sysinfo() syscall is supposed to be used
+        # as a fallback.
+        def open_mock(name, *args, **kwargs):
+            if name == "/proc/meminfo":
+                return io.BytesIO(b"")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, create=True, side_effect=open_mock) as m:
+            psutil.swap_memory()
+            assert m.called
+
+
+# =====================================================================
+# --- system CPU
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestSystemCPU(unittest.TestCase):
+
+    @unittest.skipIf(TRAVIS, "unknown failure on travis")
+    def test_cpu_times(self):
+        fields = psutil.cpu_times()._fields
+        kernel_ver = re.findall(r'\d+\.\d+\.\d+', os.uname()[2])[0]
+        kernel_ver_info = tuple(map(int, kernel_ver.split('.')))
+        if kernel_ver_info >= (2, 6, 11):
+            self.assertIn('steal', fields)
+        else:
+            self.assertNotIn('steal', fields)
+        if kernel_ver_info >= (2, 6, 24):
+            self.assertIn('guest', fields)
+        else:
+            self.assertNotIn('guest', fields)
+        if kernel_ver_info >= (3, 2, 0):
+            self.assertIn('guest_nice', fields)
+        else:
+            self.assertNotIn('guest_nice', fields)
+
+    @unittest.skipIf(not os.path.exists("/sys/devices/system/cpu/online"),
+                     "/sys/devices/system/cpu/online does not exist")
+    def test_cpu_count_logical_w_sysdev_cpu_online(self):
+        with open("/sys/devices/system/cpu/online") as f:
+            value = f.read().strip()
+        if "-" in str(value):
+            value = int(value.split('-')[1]) + 1
+            self.assertEqual(psutil.cpu_count(), value)
+
+    @unittest.skipIf(not os.path.exists("/sys/devices/system/cpu"),
+                     "/sys/devices/system/cpu does not exist")
+    def test_cpu_count_logical_w_sysdev_cpu_num(self):
+        ls = os.listdir("/sys/devices/system/cpu")
+        count = len([x for x in ls if re.search(r"cpu\d+$", x) is not None])
+        self.assertEqual(psutil.cpu_count(), count)
+
+    @unittest.skipIf(not which("nproc"), "nproc utility not available")
+    def test_cpu_count_logical_w_nproc(self):
+        num = int(sh("nproc --all"))
+        self.assertEqual(psutil.cpu_count(logical=True), num)
+
+    @unittest.skipIf(not which("lscpu"), "lscpu utility not available")
+    def test_cpu_count_logical_w_lscpu(self):
+        out = sh("lscpu -p")
+        num = len([x for x in out.split('\n') if not x.startswith('#')])
+        self.assertEqual(psutil.cpu_count(logical=True), num)
+
+    def test_cpu_count_logical_mocked(self):
+        import psutil._pslinux
+        original = psutil._pslinux.cpu_count_logical()
+        # Here we want to mock os.sysconf("SC_NPROCESSORS_ONLN") in
+        # order to cause the parsing of /proc/cpuinfo and /proc/stat.
+        with mock.patch(
+                'psutil._pslinux.os.sysconf', side_effect=ValueError) as m:
+            self.assertEqual(psutil._pslinux.cpu_count_logical(), original)
+            assert m.called
+
+            # Let's have open() return emtpy data and make sure None is
+            # returned ('cause we mimick os.cpu_count()).
+            with mock.patch('psutil._pslinux.open', create=True) as m:
+                self.assertIsNone(psutil._pslinux.cpu_count_logical())
+                self.assertEqual(m.call_count, 2)
+                # /proc/stat should be the last one
+                self.assertEqual(m.call_args[0][0], '/proc/stat')
+
+            # Let's push this a bit further and make sure /proc/cpuinfo
+            # parsing works as expected.
+            with open('/proc/cpuinfo', 'rb') as f:
+                cpuinfo_data = f.read()
+            fake_file = io.BytesIO(cpuinfo_data)
+            with mock.patch('psutil._pslinux.open',
+                            return_value=fake_file, create=True) as m:
+                self.assertEqual(psutil._pslinux.cpu_count_logical(), original)
+
+            # Finally, let's make /proc/cpuinfo return meaningless data;
+            # this way we'll fall back on relying on /proc/stat
+            def open_mock(name, *args, **kwargs):
+                if name.startswith('/proc/cpuinfo'):
+                    return io.BytesIO(b"")
+                else:
+                    return orig_open(name, *args, **kwargs)
+
+            orig_open = open
+            patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+            with mock.patch(patch_point, side_effect=open_mock, create=True):
+                self.assertEqual(psutil._pslinux.cpu_count_logical(), original)
+
+    def test_cpu_count_physical_mocked(self):
+        # Have open() return emtpy data and make sure None is returned
+        # ('cause we want to mimick os.cpu_count())
+        with mock.patch('psutil._pslinux.open', create=True) as m:
+            self.assertIsNone(psutil._pslinux.cpu_count_physical())
+            assert m.called
+
+    @unittest.skipIf(not HAS_CPU_FREQ, "not supported")
+    def test_cpu_freq_no_result(self):
+        with mock.patch("psutil._pslinux.glob.glob", return_value=[]):
+            self.assertIsNone(psutil.cpu_freq())
+
+    @unittest.skipIf(TRAVIS, "fails on Travis")
+    @unittest.skipIf(not HAS_CPU_FREQ, "not supported")
+    def test_cpu_freq_use_second_file(self):
+        # https://github.com/giampaolo/psutil/issues/981
+        def glob_mock(pattern):
+            if pattern.startswith("/sys/devices/system/cpu/cpufreq/policy"):
+                flags.append(None)
+                return []
+            else:
+                flags.append(None)
+                return orig_glob(pattern)
+
+        flags = []
+        orig_glob = glob.glob
+        with mock.patch("psutil._pslinux.glob.glob", side_effect=glob_mock,
+                        create=True):
+            assert psutil.cpu_freq()
+            self.assertEqual(len(flags), 2)
+
+    @unittest.skipIf(not HAS_CPU_FREQ, "not supported")
+    def test_cpu_freq_emulate_data(self):
+        def open_mock(name, *args, **kwargs):
+            if name.endswith('/scaling_cur_freq'):
+                return io.BytesIO(b"500000")
+            elif name.endswith('/scaling_min_freq'):
+                return io.BytesIO(b"600000")
+            elif name.endswith('/scaling_max_freq'):
+                return io.BytesIO(b"700000")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock):
+            with mock.patch(
+                    'glob.glob',
+                    return_value=['/sys/devices/system/cpu/cpufreq/policy0']):
+                freq = psutil.cpu_freq()
+                self.assertEqual(freq.current, 500.0)
+                self.assertEqual(freq.min, 600.0)
+                self.assertEqual(freq.max, 700.0)
+
+    @unittest.skipIf(not HAS_CPU_FREQ, "not supported")
+    def test_cpu_freq_emulate_multi_cpu(self):
+        def open_mock(name, *args, **kwargs):
+            if name.endswith('/scaling_cur_freq'):
+                return io.BytesIO(b"100000")
+            elif name.endswith('/scaling_min_freq'):
+                return io.BytesIO(b"200000")
+            elif name.endswith('/scaling_max_freq'):
+                return io.BytesIO(b"300000")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        policies = ['/sys/devices/system/cpu/cpufreq/policy0',
+                    '/sys/devices/system/cpu/cpufreq/policy1',
+                    '/sys/devices/system/cpu/cpufreq/policy2']
+        with mock.patch(patch_point, side_effect=open_mock):
+            with mock.patch('glob.glob', return_value=policies):
+                freq = psutil.cpu_freq()
+                self.assertEqual(freq.current, 100.0)
+                self.assertEqual(freq.min, 200.0)
+                self.assertEqual(freq.max, 300.0)
+
+    @unittest.skipIf(TRAVIS, "fails on Travis")
+    @unittest.skipIf(not HAS_CPU_FREQ, "not supported")
+    def test_cpu_freq_no_scaling_cur_freq_file(self):
+        # See: https://github.com/giampaolo/psutil/issues/1071
+        def open_mock(name, *args, **kwargs):
+            if name.endswith('/scaling_cur_freq'):
+                raise IOError(errno.ENOENT, "")
+            elif name.endswith('/cpuinfo_cur_freq'):
+                return io.BytesIO(b"200000")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        policies = ['/sys/devices/system/cpu/cpufreq/policy0',
+                    '/sys/devices/system/cpu/cpufreq/policy1',
+                    '/sys/devices/system/cpu/cpufreq/policy2']
+
+        with mock.patch(patch_point, side_effect=open_mock):
+            with mock.patch('glob.glob', return_value=policies):
+                freq = psutil.cpu_freq()
+                self.assertEqual(freq.current, 200)
+
+        # Also test that NotImplementedError is raised in case no
+        # current freq file is present.
+
+        def open_mock(name, *args, **kwargs):
+            if name.endswith('/scaling_cur_freq'):
+                raise IOError(errno.ENOENT, "")
+            elif name.endswith('/cpuinfo_cur_freq'):
+                raise IOError(errno.ENOENT, "")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock):
+            with mock.patch('glob.glob', return_value=policies):
+                self.assertRaises(NotImplementedError, psutil.cpu_freq)
+
+
+# =====================================================================
+# --- system CPU stats
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestSystemCPUStats(unittest.TestCase):
+
+    @unittest.skipIf(TRAVIS, "fails on Travis")
+    def test_ctx_switches(self):
+        vmstat_value = vmstat("context switches")
+        psutil_value = psutil.cpu_stats().ctx_switches
+        self.assertAlmostEqual(vmstat_value, psutil_value, delta=500)
+
+    @unittest.skipIf(TRAVIS, "fails on Travis")
+    def test_interrupts(self):
+        vmstat_value = vmstat("interrupts")
+        psutil_value = psutil.cpu_stats().interrupts
+        self.assertAlmostEqual(vmstat_value, psutil_value, delta=500)
+
+
+# =====================================================================
+# --- system network
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestSystemNetwork(unittest.TestCase):
+
+    def test_net_if_addrs_ips(self):
+        for name, addrs in psutil.net_if_addrs().items():
+            for addr in addrs:
+                if addr.family == psutil.AF_LINK:
+                    self.assertEqual(addr.address, get_mac_address(name))
+                elif addr.family == socket.AF_INET:
+                    self.assertEqual(addr.address, get_ipv4_address(name))
+                # TODO: test for AF_INET6 family
+
+    def test_net_if_stats(self):
+        for name, stats in psutil.net_if_stats().items():
+            try:
+                out = sh("ifconfig %s" % name)
+            except RuntimeError:
+                pass
+            else:
+                # Not always reliable.
+                # self.assertEqual(stats.isup, 'RUNNING' in out, msg=out)
+                self.assertEqual(stats.mtu,
+                                 int(re.findall(r'(?i)MTU[: ](\d+)', out)[0]))
+
+    @retry_before_failing()
+    def test_net_io_counters(self):
+        def ifconfig(nic):
+            ret = {}
+            out = sh("ifconfig %s" % name)
+            ret['packets_recv'] = int(
+                re.findall(r'RX packets[: ](\d+)', out)[0])
+            ret['packets_sent'] = int(
+                re.findall(r'TX packets[: ](\d+)', out)[0])
+            ret['errin'] = int(re.findall(r'errors[: ](\d+)', out)[0])
+            ret['errout'] = int(re.findall(r'errors[: ](\d+)', out)[1])
+            ret['dropin'] = int(re.findall(r'dropped[: ](\d+)', out)[0])
+            ret['dropout'] = int(re.findall(r'dropped[: ](\d+)', out)[1])
+            ret['bytes_recv'] = int(
+                re.findall(r'RX (?:packets \d+ +)?bytes[: ](\d+)', out)[0])
+            ret['bytes_sent'] = int(
+                re.findall(r'TX (?:packets \d+ +)?bytes[: ](\d+)', out)[0])
+            return ret
+
+        nio = psutil.net_io_counters(pernic=True, nowrap=False)
+        for name, stats in nio.items():
+            try:
+                ifconfig_ret = ifconfig(name)
+            except RuntimeError:
+                continue
+            self.assertAlmostEqual(
+                stats.bytes_recv, ifconfig_ret['bytes_recv'], delta=1024 * 5)
+            self.assertAlmostEqual(
+                stats.bytes_sent, ifconfig_ret['bytes_sent'], delta=1024 * 5)
+            self.assertAlmostEqual(
+                stats.packets_recv, ifconfig_ret['packets_recv'], delta=1024)
+            self.assertAlmostEqual(
+                stats.packets_sent, ifconfig_ret['packets_sent'], delta=1024)
+            self.assertAlmostEqual(
+                stats.errin, ifconfig_ret['errin'], delta=10)
+            self.assertAlmostEqual(
+                stats.errout, ifconfig_ret['errout'], delta=10)
+            self.assertAlmostEqual(
+                stats.dropin, ifconfig_ret['dropin'], delta=10)
+            self.assertAlmostEqual(
+                stats.dropout, ifconfig_ret['dropout'], delta=10)
+
+    @unittest.skipIf(not which('ip'), "'ip' utility not available")
+    @unittest.skipIf(TRAVIS, "skipped on Travis")
+    def test_net_if_names(self):
+        out = sh("ip addr").strip()
+        nics = [x for x in psutil.net_if_addrs().keys() if ':' not in x]
+        found = 0
+        for line in out.split('\n'):
+            line = line.strip()
+            if re.search(r"^\d+:", line):
+                found += 1
+                name = line.split(':')[1].strip()
+                self.assertIn(name, nics)
+        self.assertEqual(len(nics), found, msg="%s\n---\n%s" % (
+            pprint.pformat(nics), out))
+
+    @mock.patch('psutil._pslinux.socket.inet_ntop', side_effect=ValueError)
+    @mock.patch('psutil._pslinux.supports_ipv6', return_value=False)
+    def test_net_connections_ipv6_unsupported(self, supports_ipv6, inet_ntop):
+        # see: https://github.com/giampaolo/psutil/issues/623
+        try:
+            s = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
+            self.addCleanup(s.close)
+            s.bind(("::1", 0))
+        except socket.error:
+            pass
+        psutil.net_connections(kind='inet6')
+
+    def test_net_connections_mocked(self):
+        def open_mock(name, *args, **kwargs):
+            if name == '/proc/net/unix':
+                return io.StringIO(textwrap.dedent(u"""\
+                    0: 00000003 000 000 0001 03 462170 @/tmp/dbus-Qw2hMPIU3n
+                    0: 00000003 000 000 0001 03 35010 @/tmp/dbus-tB2X8h69BQ
+                    0: 00000003 000 000 0001 03 34424 @/tmp/dbus-cHy80Y8O
+                    000000000000000000000000000000000000000000000000000000
+                    """))
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            psutil.net_connections(kind='unix')
+            assert m.called
+
+
+# =====================================================================
+# --- system disk
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestSystemDisks(unittest.TestCase):
+
+    @unittest.skipIf(not hasattr(os, 'statvfs'), "os.statvfs() not available")
+    @skip_on_not_implemented()
+    def test_disk_partitions_and_usage(self):
+        # test psutil.disk_usage() and psutil.disk_partitions()
+        # against "df -a"
+        def df(path):
+            out = sh('df -P -B 1 "%s"' % path).strip()
+            lines = out.split('\n')
+            lines.pop(0)
+            line = lines.pop(0)
+            dev, total, used, free = line.split()[:4]
+            if dev == 'none':
+                dev = ''
+            total, used, free = int(total), int(used), int(free)
+            return dev, total, used, free
+
+        for part in psutil.disk_partitions(all=False):
+            usage = psutil.disk_usage(part.mountpoint)
+            dev, total, used, free = df(part.mountpoint)
+            self.assertEqual(usage.total, total)
+            # 10 MB tollerance
+            if abs(usage.free - free) > 10 * 1024 * 1024:
+                self.fail("psutil=%s, df=%s" % (usage.free, free))
+            if abs(usage.used - used) > 10 * 1024 * 1024:
+                self.fail("psutil=%s, df=%s" % (usage.used, used))
+
+    def test_disk_partitions_mocked(self):
+        # Test that ZFS partitions are returned.
+        with open("/proc/filesystems", "r") as f:
+            data = f.read()
+        if 'zfs' in data:
+            for part in psutil.disk_partitions():
+                if part.fstype == 'zfs':
+                    break
+            else:
+                self.fail("couldn't find any ZFS partition")
+        else:
+            # No ZFS partitions on this system. Let's fake one.
+            fake_file = io.StringIO(u("nodev\tzfs\n"))
+            with mock.patch('psutil._pslinux.open',
+                            return_value=fake_file, create=True) as m1:
+                with mock.patch(
+                        'psutil._pslinux.cext.disk_partitions',
+                        return_value=[('/dev/sdb3', '/', 'zfs', 'rw')]) as m2:
+                    ret = psutil.disk_partitions()
+                    assert m1.called
+                    assert m2.called
+                    assert ret
+                    self.assertEqual(ret[0].fstype, 'zfs')
+
+    def test_disk_io_counters_kernel_2_4_mocked(self):
+        # Tests /proc/diskstats parsing format for 2.4 kernels, see:
+        # https://github.com/giampaolo/psutil/issues/767
+        def open_mock(name, *args, **kwargs):
+            if name == '/proc/partitions':
+                return io.StringIO(textwrap.dedent(u"""\
+                    major minor  #blocks  name
+
+                       8        0  488386584 hda
+                    """))
+            elif name == '/proc/diskstats':
+                return io.StringIO(
+                    u("   3     0   1 hda 2 3 4 5 6 7 8 9 10 11 12"))
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            ret = psutil.disk_io_counters(nowrap=False)
+            assert m.called
+            self.assertEqual(ret.read_count, 1)
+            self.assertEqual(ret.read_merged_count, 2)
+            self.assertEqual(ret.read_bytes, 3 * SECTOR_SIZE)
+            self.assertEqual(ret.read_time, 4)
+            self.assertEqual(ret.write_count, 5)
+            self.assertEqual(ret.write_merged_count, 6)
+            self.assertEqual(ret.write_bytes, 7 * SECTOR_SIZE)
+            self.assertEqual(ret.write_time, 8)
+            self.assertEqual(ret.busy_time, 10)
+
+    def test_disk_io_counters_kernel_2_6_full_mocked(self):
+        # Tests /proc/diskstats parsing format for 2.6 kernels,
+        # lines reporting all metrics:
+        # https://github.com/giampaolo/psutil/issues/767
+        def open_mock(name, *args, **kwargs):
+            if name == '/proc/partitions':
+                return io.StringIO(textwrap.dedent(u"""\
+                    major minor  #blocks  name
+
+                       8        0  488386584 hda
+                    """))
+            elif name == '/proc/diskstats':
+                return io.StringIO(
+                    u("   3    0   hda 1 2 3 4 5 6 7 8 9 10 11"))
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            ret = psutil.disk_io_counters(nowrap=False)
+            assert m.called
+            self.assertEqual(ret.read_count, 1)
+            self.assertEqual(ret.read_merged_count, 2)
+            self.assertEqual(ret.read_bytes, 3 * SECTOR_SIZE)
+            self.assertEqual(ret.read_time, 4)
+            self.assertEqual(ret.write_count, 5)
+            self.assertEqual(ret.write_merged_count, 6)
+            self.assertEqual(ret.write_bytes, 7 * SECTOR_SIZE)
+            self.assertEqual(ret.write_time, 8)
+            self.assertEqual(ret.busy_time, 10)
+
+    def test_disk_io_counters_kernel_2_6_limited_mocked(self):
+        # Tests /proc/diskstats parsing format for 2.6 kernels,
+        # where one line of /proc/partitions return a limited
+        # amount of metrics when it bumps into a partition
+        # (instead of a disk). See:
+        # https://github.com/giampaolo/psutil/issues/767
+        def open_mock(name, *args, **kwargs):
+            if name == '/proc/partitions':
+                return io.StringIO(textwrap.dedent(u"""\
+                    major minor  #blocks  name
+
+                       8        0  488386584 hda
+                    """))
+            elif name == '/proc/diskstats':
+                return io.StringIO(
+                    u("   3    1   hda 1 2 3 4"))
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            ret = psutil.disk_io_counters(nowrap=False)
+            assert m.called
+            self.assertEqual(ret.read_count, 1)
+            self.assertEqual(ret.read_bytes, 2 * SECTOR_SIZE)
+            self.assertEqual(ret.write_count, 3)
+            self.assertEqual(ret.write_bytes, 4 * SECTOR_SIZE)
+
+            self.assertEqual(ret.read_merged_count, 0)
+            self.assertEqual(ret.read_time, 0)
+            self.assertEqual(ret.write_merged_count, 0)
+            self.assertEqual(ret.write_time, 0)
+            self.assertEqual(ret.busy_time, 0)
+
+
+# =====================================================================
+# --- misc
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestMisc(unittest.TestCase):
+
+    def test_boot_time(self):
+        vmstat_value = vmstat('boot time')
+        psutil_value = psutil.boot_time()
+        self.assertEqual(int(vmstat_value), int(psutil_value))
+
+    @mock.patch('psutil.traceback.print_exc')
+    def test_no_procfs_on_import(self, tb):
+        my_procfs = tempfile.mkdtemp()
+
+        with open(os.path.join(my_procfs, 'stat'), 'w') as f:
+            f.write('cpu   0 0 0 0 0 0 0 0 0 0\n')
+            f.write('cpu0  0 0 0 0 0 0 0 0 0 0\n')
+            f.write('cpu1  0 0 0 0 0 0 0 0 0 0\n')
+
+        try:
+            orig_open = open
+
+            def open_mock(name, *args, **kwargs):
+                if name.startswith('/proc'):
+                    raise IOError(errno.ENOENT, 'rejecting access for test')
+                return orig_open(name, *args, **kwargs)
+
+            patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+            with mock.patch(patch_point, side_effect=open_mock):
+                reload_module(psutil)
+                assert tb.called
+
+                self.assertRaises(IOError, psutil.cpu_times)
+                self.assertRaises(IOError, psutil.cpu_times, percpu=True)
+                self.assertRaises(IOError, psutil.cpu_percent)
+                self.assertRaises(IOError, psutil.cpu_percent, percpu=True)
+                self.assertRaises(IOError, psutil.cpu_times_percent)
+                self.assertRaises(
+                    IOError, psutil.cpu_times_percent, percpu=True)
+
+                psutil.PROCFS_PATH = my_procfs
+
+                self.assertEqual(psutil.cpu_percent(), 0)
+                self.assertEqual(sum(psutil.cpu_times_percent()), 0)
+
+                # since we don't know the number of CPUs at import time,
+                # we awkwardly say there are none until the second call
+                per_cpu_percent = psutil.cpu_percent(percpu=True)
+                self.assertEqual(sum(per_cpu_percent), 0)
+
+                # ditto awkward length
+                per_cpu_times_percent = psutil.cpu_times_percent(percpu=True)
+                self.assertEqual(sum(map(sum, per_cpu_times_percent)), 0)
+
+                # much user, very busy
+                with open(os.path.join(my_procfs, 'stat'), 'w') as f:
+                    f.write('cpu   1 0 0 0 0 0 0 0 0 0\n')
+                    f.write('cpu0  1 0 0 0 0 0 0 0 0 0\n')
+                    f.write('cpu1  1 0 0 0 0 0 0 0 0 0\n')
+
+                self.assertNotEqual(psutil.cpu_percent(), 0)
+                self.assertNotEqual(
+                    sum(psutil.cpu_percent(percpu=True)), 0)
+                self.assertNotEqual(sum(psutil.cpu_times_percent()), 0)
+                self.assertNotEqual(
+                    sum(map(sum, psutil.cpu_times_percent(percpu=True))), 0)
+        finally:
+            shutil.rmtree(my_procfs)
+            reload_module(psutil)
+
+        self.assertEqual(psutil.PROCFS_PATH, '/proc')
+
+    def test_boot_time_mocked(self):
+        with mock.patch('psutil._pslinux.open', create=True) as m:
+            self.assertRaises(
+                RuntimeError,
+                psutil._pslinux.boot_time)
+            assert m.called
+
+    def test_users_mocked(self):
+        # Make sure ':0' and ':0.0' (returned by C ext) are converted
+        # to 'localhost'.
+        with mock.patch('psutil._pslinux.cext.users',
+                        return_value=[('giampaolo', 'pts/2', ':0',
+                                       1436573184.0, True, 2)]) as m:
+            self.assertEqual(psutil.users()[0].host, 'localhost')
+            assert m.called
+        with mock.patch('psutil._pslinux.cext.users',
+                        return_value=[('giampaolo', 'pts/2', ':0.0',
+                                       1436573184.0, True, 2)]) as m:
+            self.assertEqual(psutil.users()[0].host, 'localhost')
+            assert m.called
+        # ...otherwise it should be returned as-is
+        with mock.patch('psutil._pslinux.cext.users',
+                        return_value=[('giampaolo', 'pts/2', 'foo',
+                                       1436573184.0, True, 2)]) as m:
+            self.assertEqual(psutil.users()[0].host, 'foo')
+            assert m.called
+
+    def test_procfs_path(self):
+        tdir = tempfile.mkdtemp()
+        try:
+            psutil.PROCFS_PATH = tdir
+            self.assertRaises(IOError, psutil.virtual_memory)
+            self.assertRaises(IOError, psutil.cpu_times)
+            self.assertRaises(IOError, psutil.cpu_times, percpu=True)
+            self.assertRaises(IOError, psutil.boot_time)
+            # self.assertRaises(IOError, psutil.pids)
+            self.assertRaises(IOError, psutil.net_connections)
+            self.assertRaises(IOError, psutil.net_io_counters)
+            self.assertRaises(IOError, psutil.net_if_stats)
+            self.assertRaises(IOError, psutil.disk_io_counters)
+            self.assertRaises(IOError, psutil.disk_partitions)
+            self.assertRaises(psutil.NoSuchProcess, psutil.Process)
+        finally:
+            psutil.PROCFS_PATH = "/proc"
+            os.rmdir(tdir)
+
+    def test_sector_size_mock(self):
+        # Test SECTOR_SIZE fallback in case 'hw_sector_size' file
+        # does not exist.
+        def open_mock(name, *args, **kwargs):
+            if PY3 and isinstance(name, bytes):
+                name = name.decode()
+            if "hw_sector_size" in name:
+                flag.append(None)
+                raise IOError(errno.ENOENT, '')
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        flag = []
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock):
+            psutil.disk_io_counters()
+            assert flag
+
+    def test_issue_687(self):
+        # In case of thread ID:
+        # - pid_exists() is supposed to return False
+        # - Process(tid) is supposed to work
+        # - pids() should not return the TID
+        # See: https://github.com/giampaolo/psutil/issues/687
+        t = ThreadTask()
+        t.start()
+        try:
+            p = psutil.Process()
+            tid = p.threads()[1].id
+            assert not psutil.pid_exists(tid), tid
+            pt = psutil.Process(tid)
+            pt.as_dict()
+            self.assertNotIn(tid, psutil.pids())
+        finally:
+            t.stop()
+
+    def test_pid_exists_no_proc_status(self):
+        # Internally pid_exists relies on /proc/{pid}/status.
+        # Emulate a case where this file is empty in which case
+        # psutil is supposed to fall back on using pids().
+        def open_mock(name, *args, **kwargs):
+            if name == "/proc/%s/status" % os.getpid():
+                return io.StringIO(u(""))
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock):
+            assert psutil.pid_exists(os.getpid())
+
+
+# =====================================================================
+# --- sensors
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+@unittest.skipIf(not HAS_BATTERY, "no battery")
+class TestSensorsBattery(unittest.TestCase):
+
+    @unittest.skipIf(not which("acpi"), "acpi utility not available")
+    def test_percent(self):
+        out = sh("acpi -b")
+        acpi_value = int(out.split(",")[1].strip().replace('%', ''))
+        psutil_value = psutil.sensors_battery().percent
+        self.assertAlmostEqual(acpi_value, psutil_value, delta=1)
+
+    @unittest.skipIf(not which("acpi"), "acpi utility not available")
+    def test_power_plugged(self):
+        out = sh("acpi -b")
+        if 'unknown' in out.lower():
+            return unittest.skip("acpi output not reliable")
+        if 'discharging at zero rate' in out:
+            plugged = True
+        else:
+            plugged = "Charging" in out.split('\n')[0]
+        self.assertEqual(psutil.sensors_battery().power_plugged, plugged)
+
+    def test_emulate_power_plugged(self):
+        # Pretend the AC power cable is connected.
+        def open_mock(name, *args, **kwargs):
+            if name.endswith("AC0/online") or name.endswith("AC/online"):
+                return io.BytesIO(b"1")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            self.assertEqual(psutil.sensors_battery().power_plugged, True)
+            self.assertEqual(
+                psutil.sensors_battery().secsleft, psutil.POWER_TIME_UNLIMITED)
+            assert m.called
+
+    def test_emulate_power_plugged_2(self):
+        # Same as above but pretend /AC0/online does not exist in which
+        # case code relies on /status file.
+        def open_mock(name, *args, **kwargs):
+            if name.endswith("AC0/online") or name.endswith("AC/online"):
+                raise IOError(errno.ENOENT, "")
+            elif name.endswith("/status"):
+                return io.StringIO(u("charging"))
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            self.assertEqual(psutil.sensors_battery().power_plugged, True)
+            assert m.called
+
+    def test_emulate_power_not_plugged(self):
+        # Pretend the AC power cable is not connected.
+        def open_mock(name, *args, **kwargs):
+            if name.endswith("AC0/online") or name.endswith("AC/online"):
+                return io.BytesIO(b"0")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            self.assertEqual(psutil.sensors_battery().power_plugged, False)
+            assert m.called
+
+    def test_emulate_power_not_plugged_2(self):
+        # Same as above but pretend /AC0/online does not exist in which
+        # case code relies on /status file.
+        def open_mock(name, *args, **kwargs):
+            if name.endswith("AC0/online") or name.endswith("AC/online"):
+                raise IOError(errno.ENOENT, "")
+            elif name.endswith("/status"):
+                return io.StringIO(u("discharging"))
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            self.assertEqual(psutil.sensors_battery().power_plugged, False)
+            assert m.called
+
+    def test_emulate_power_undetermined(self):
+        # Pretend we can't know whether the AC power cable not
+        # connected (assert fallback to False).
+        def open_mock(name, *args, **kwargs):
+            if name.startswith("/sys/class/power_supply/AC0/online") or \
+                    name.startswith("/sys/class/power_supply/AC/online"):
+                raise IOError(errno.ENOENT, "")
+            elif name.startswith("/sys/class/power_supply/BAT0/status"):
+                return io.BytesIO(b"???")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            self.assertIsNone(psutil.sensors_battery().power_plugged)
+            assert m.called
+
+    def test_emulate_no_base_files(self):
+        # Emulate a case where base metrics files are not present,
+        # in which case we're supposed to get None.
+        def open_mock(name, *args, **kwargs):
+            if name.startswith("/sys/class/power_supply/BAT0/energy_now") or \
+                    name.startswith("/sys/class/power_supply/BAT0/charge_now"):
+                raise IOError(errno.ENOENT, "")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            self.assertIsNone(psutil.sensors_battery())
+            assert m.called
+
+    def test_emulate_energy_full_0(self):
+        # Emulate a case where energy_full files returns 0.
+        def open_mock(name, *args, **kwargs):
+            if name.startswith("/sys/class/power_supply/BAT0/energy_full"):
+                return io.BytesIO(b"0")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            self.assertEqual(psutil.sensors_battery().percent, 0)
+            assert m.called
+
+    def test_emulate_energy_full_not_avail(self):
+        # Emulate a case where energy_full file does not exist.
+        # Expected fallback on /capacity.
+        def open_mock(name, *args, **kwargs):
+            energy_full = "/sys/class/power_supply/BAT0/energy_full"
+            charge_full = "/sys/class/power_supply/BAT0/charge_full"
+            if name.startswith(energy_full) or name.startswith(charge_full):
+                raise IOError(errno.ENOENT, "")
+            elif name.startswith("/sys/class/power_supply/BAT0/capacity"):
+                return io.BytesIO(b"88")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            self.assertEqual(psutil.sensors_battery().percent, 88)
+            assert m.called
+
+    def test_emulate_no_ac0_online(self):
+        # Emulate a case where /AC0/online file does not exist.
+        def path_exists_mock(name):
+            if name.startswith("/sys/class/power_supply/AC0/online"):
+                return False
+            else:
+                return orig_path_exists(name)
+
+        orig_path_exists = os.path.exists
+        with mock.patch("psutil._pslinux.os.path.exists",
+                        side_effect=path_exists_mock) as m:
+            psutil.sensors_battery()
+            assert m.called
+
+    def test_emulate_no_power(self):
+        # Emulate a case where /AC0/online file nor /BAT0/status exist.
+        def open_mock(name, *args, **kwargs):
+            if name.startswith("/sys/class/power_supply/AC/online") or \
+                    name.startswith("/sys/class/power_supply/AC0/online") or \
+                    name.startswith("/sys/class/power_supply/BAT0/status"):
+                raise IOError(errno.ENOENT, "")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            self.assertIsNone(psutil.sensors_battery().power_plugged)
+            assert m.called
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestSensorsTemperatures(unittest.TestCase):
+
+    @unittest.skipIf(TRAVIS, "unreliable on TRAVIS")
+    def test_emulate_eio_error(self):
+        def open_mock(name, *args, **kwargs):
+            if name.endswith("_input"):
+                raise OSError(errno.EIO, "")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            with warnings.catch_warnings(record=True) as ws:
+                self.assertEqual(psutil.sensors_temperatures(), {})
+                assert m.called
+                self.assertIn("ignoring", str(ws[0].message))
+
+    def test_emulate_data(self):
+        def open_mock(name, *args, **kwargs):
+            if name.endswith('/name'):
+                return io.StringIO(u("name"))
+            elif name.endswith('/temp1_label'):
+                return io.StringIO(u("label"))
+            elif name.endswith('/temp1_input'):
+                return io.BytesIO(b"30000")
+            elif name.endswith('/temp1_max'):
+                return io.BytesIO(b"40000")
+            elif name.endswith('/temp1_crit'):
+                return io.BytesIO(b"50000")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock):
+            with mock.patch('glob.glob',
+                            return_value=['/sys/class/hwmon/hwmon0/temp1']):
+                temp = psutil.sensors_temperatures()['name'][0]
+                self.assertEqual(temp.label, 'label')
+                self.assertEqual(temp.current, 30.0)
+                self.assertEqual(temp.high, 40.0)
+                self.assertEqual(temp.critical, 50.0)
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestSensorsFans(unittest.TestCase):
+
+    def test_emulate_data(self):
+        def open_mock(name, *args, **kwargs):
+            if name.endswith('/name'):
+                return io.StringIO(u("name"))
+            elif name.endswith('/fan1_label'):
+                return io.StringIO(u("label"))
+            elif name.endswith('/fan1_input'):
+                return io.StringIO(u("2000"))
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock):
+            with mock.patch('glob.glob',
+                            return_value=['/sys/class/hwmon/hwmon2/fan1']):
+                fan = psutil.sensors_fans()['name'][0]
+                self.assertEqual(fan.label, 'label')
+                self.assertEqual(fan.current, 2000)
+
+
+# =====================================================================
+# --- test process
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestProcess(unittest.TestCase):
+
+    def setUp(self):
+        safe_rmpath(TESTFN)
+
+    tearDown = setUp
+
+    def test_memory_full_info(self):
+        src = textwrap.dedent("""
+            import time
+            with open("%s", "w") as f:
+                time.sleep(10)
+            """ % TESTFN)
+        sproc = pyrun(src)
+        self.addCleanup(reap_children)
+        call_until(lambda: os.listdir('.'), "'%s' not in ret" % TESTFN)
+        p = psutil.Process(sproc.pid)
+        time.sleep(.1)
+        mem = p.memory_full_info()
+        maps = p.memory_maps(grouped=False)
+        self.assertAlmostEqual(
+            mem.uss, sum([x.private_dirty + x.private_clean for x in maps]),
+            delta=4096)
+        self.assertAlmostEqual(
+            mem.pss, sum([x.pss for x in maps]), delta=4096)
+        self.assertAlmostEqual(
+            mem.swap, sum([x.swap for x in maps]), delta=4096)
+
+    # On PYPY file descriptors are not closed fast enough.
+    @unittest.skipIf(PYPY, "unreliable on PYPY")
+    def test_open_files_mode(self):
+        def get_test_file():
+            p = psutil.Process()
+            giveup_at = time.time() + 2
+            while True:
+                for file in p.open_files():
+                    if file.path == os.path.abspath(TESTFN):
+                        return file
+                    elif time.time() > giveup_at:
+                        break
+            raise RuntimeError("timeout looking for test file")
+
+        #
+        with open(TESTFN, "w"):
+            self.assertEqual(get_test_file().mode, "w")
+        with open(TESTFN, "r"):
+            self.assertEqual(get_test_file().mode, "r")
+        with open(TESTFN, "a"):
+            self.assertEqual(get_test_file().mode, "a")
+        #
+        with open(TESTFN, "r+"):
+            self.assertEqual(get_test_file().mode, "r+")
+        with open(TESTFN, "w+"):
+            self.assertEqual(get_test_file().mode, "r+")
+        with open(TESTFN, "a+"):
+            self.assertEqual(get_test_file().mode, "a+")
+        # note: "x" bit is not supported
+        if PY3:
+            safe_rmpath(TESTFN)
+            with open(TESTFN, "x"):
+                self.assertEqual(get_test_file().mode, "w")
+            safe_rmpath(TESTFN)
+            with open(TESTFN, "x+"):
+                self.assertEqual(get_test_file().mode, "r+")
+
+    def test_open_files_file_gone(self):
+        # simulates a file which gets deleted during open_files()
+        # execution
+        p = psutil.Process()
+        files = p.open_files()
+        with tempfile.NamedTemporaryFile():
+            # give the kernel some time to see the new file
+            call_until(p.open_files, "len(ret) != %i" % len(files))
+            with mock.patch('psutil._pslinux.os.readlink',
+                            side_effect=OSError(errno.ENOENT, "")) as m:
+                files = p.open_files()
+                assert not files
+                assert m.called
+            # also simulate the case where os.readlink() returns EINVAL
+            # in which case psutil is supposed to 'continue'
+            with mock.patch('psutil._pslinux.os.readlink',
+                            side_effect=OSError(errno.EINVAL, "")) as m:
+                self.assertEqual(p.open_files(), [])
+                assert m.called
+
+    def test_open_files_fd_gone(self):
+        # Simulate a case where /proc/{pid}/fdinfo/{fd} disappears
+        # while iterating through fds.
+        # https://travis-ci.org/giampaolo/psutil/jobs/225694530
+        p = psutil.Process()
+        files = p.open_files()
+        with tempfile.NamedTemporaryFile():
+            # give the kernel some time to see the new file
+            call_until(p.open_files, "len(ret) != %i" % len(files))
+            patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+            with mock.patch(patch_point,
+                            side_effect=IOError(errno.ENOENT, "")) as m:
+                files = p.open_files()
+                assert not files
+                assert m.called
+
+    # --- mocked tests
+
+    def test_terminal_mocked(self):
+        with mock.patch('psutil._pslinux._psposix.get_terminal_map',
+                        return_value={}) as m:
+            self.assertIsNone(psutil._pslinux.Process(os.getpid()).terminal())
+            assert m.called
+
+    # TODO: re-enable this test.
+    # def test_num_ctx_switches_mocked(self):
+    #     with mock.patch('psutil._pslinux.open', create=True) as m:
+    #         self.assertRaises(
+    #             NotImplementedError,
+    #             psutil._pslinux.Process(os.getpid()).num_ctx_switches)
+    #         assert m.called
+
+    def test_cmdline_mocked(self):
+        # see: https://github.com/giampaolo/psutil/issues/639
+        p = psutil.Process()
+        fake_file = io.StringIO(u('foo\x00bar\x00'))
+        with mock.patch('psutil._pslinux.open',
+                        return_value=fake_file, create=True) as m:
+            self.assertEqual(p.cmdline(), ['foo', 'bar'])
+            assert m.called
+        fake_file = io.StringIO(u('foo\x00bar\x00\x00'))
+        with mock.patch('psutil._pslinux.open',
+                        return_value=fake_file, create=True) as m:
+            self.assertEqual(p.cmdline(), ['foo', 'bar', ''])
+            assert m.called
+
+    def test_cmdline_spaces_mocked(self):
+        # see: https://github.com/giampaolo/psutil/issues/1179
+        p = psutil.Process()
+        fake_file = io.StringIO(u('foo bar '))
+        with mock.patch('psutil._pslinux.open',
+                        return_value=fake_file, create=True) as m:
+            self.assertEqual(p.cmdline(), ['foo', 'bar'])
+            assert m.called
+        fake_file = io.StringIO(u('foo bar  '))
+        with mock.patch('psutil._pslinux.open',
+                        return_value=fake_file, create=True) as m:
+            self.assertEqual(p.cmdline(), ['foo', 'bar', ''])
+            assert m.called
+
+    def test_readlink_path_deleted_mocked(self):
+        with mock.patch('psutil._pslinux.os.readlink',
+                        return_value='/home/foo (deleted)'):
+            self.assertEqual(psutil.Process().exe(), "/home/foo")
+            self.assertEqual(psutil.Process().cwd(), "/home/foo")
+
+    def test_threads_mocked(self):
+        # Test the case where os.listdir() returns a file (thread)
+        # which no longer exists by the time we open() it (race
+        # condition). threads() is supposed to ignore that instead
+        # of raising NSP.
+        def open_mock(name, *args, **kwargs):
+            if name.startswith('/proc/%s/task' % os.getpid()):
+                raise IOError(errno.ENOENT, "")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            ret = psutil.Process().threads()
+            assert m.called
+            self.assertEqual(ret, [])
+
+        # ...but if it bumps into something != ENOENT we want an
+        # exception.
+        def open_mock(name, *args, **kwargs):
+            if name.startswith('/proc/%s/task' % os.getpid()):
+                raise IOError(errno.EPERM, "")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        with mock.patch(patch_point, side_effect=open_mock):
+            self.assertRaises(psutil.AccessDenied, psutil.Process().threads)
+
+    def test_exe_mocked(self):
+        with mock.patch('psutil._pslinux.readlink',
+                        side_effect=OSError(errno.ENOENT, "")) as m1:
+            with mock.patch('psutil.Process.cmdline',
+                            side_effect=psutil.AccessDenied(0, "")) as m2:
+                # No such file error; might be raised also if /proc/pid/exe
+                # path actually exists for system processes with low pids
+                # (about 0-20). In this case psutil is supposed to return
+                # an empty string.
+                ret = psutil.Process().exe()
+                assert m1.called
+                assert m2.called
+                self.assertEqual(ret, "")
+
+                # ...but if /proc/pid no longer exist we're supposed to treat
+                # it as an alias for zombie process
+                with mock.patch('psutil._pslinux.os.path.lexists',
+                                return_value=False):
+                    self.assertRaises(
+                        psutil.ZombieProcess, psutil.Process().exe)
+
+    def test_issue_1014(self):
+        # Emulates a case where smaps file does not exist. In this case
+        # wrap_exception decorator should not raise NoSuchProcess.
+        def open_mock(name, *args, **kwargs):
+            if name.startswith('/proc/%s/smaps' % os.getpid()):
+                raise IOError(errno.ENOENT, "")
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock) as m:
+            p = psutil.Process()
+            with self.assertRaises(IOError) as err:
+                p.memory_maps()
+            self.assertEqual(err.exception.errno, errno.ENOENT)
+            assert m.called
+
+    @unittest.skipIf(not HAS_RLIMIT, "not supported")
+    def test_rlimit_zombie(self):
+        # Emulate a case where rlimit() raises ENOSYS, which may
+        # happen in case of zombie process:
+        # https://travis-ci.org/giampaolo/psutil/jobs/51368273
+        with mock.patch("psutil._pslinux.cext.linux_prlimit",
+                        side_effect=OSError(errno.ENOSYS, "")) as m:
+            p = psutil.Process()
+            p.name()
+            with self.assertRaises(psutil.ZombieProcess) as exc:
+                p.rlimit(psutil.RLIMIT_NOFILE)
+            assert m.called
+        self.assertEqual(exc.exception.pid, p.pid)
+        self.assertEqual(exc.exception.name, p.name())
+
+    def test_cwd_zombie(self):
+        with mock.patch("psutil._pslinux.os.readlink",
+                        side_effect=OSError(errno.ENOENT, "")) as m:
+            p = psutil.Process()
+            p.name()
+            with self.assertRaises(psutil.ZombieProcess) as exc:
+                p.cwd()
+            assert m.called
+        self.assertEqual(exc.exception.pid, p.pid)
+        self.assertEqual(exc.exception.name, p.name())
+
+    def test_stat_file_parsing(self):
+        from psutil._pslinux import CLOCK_TICKS
+
+        def open_mock(name, *args, **kwargs):
+            if name.startswith('/proc/%s/stat' % os.getpid()):
+                args = [
+                    "0",      # pid
+                    "(cat)",  # name
+                    "Z",      # status
+                    "1",      # ppid
+                    "0",      # pgrp
+                    "0",      # session
+                    "0",      # tty
+                    "0",      # tpgid
+                    "0",      # flags
+                    "0",      # minflt
+                    "0",      # cminflt
+                    "0",      # majflt
+                    "0",      # cmajflt
+                    "2",      # utime
+                    "3",      # stime
+                    "4",      # cutime
+                    "5",      # cstime
+                    "0",      # priority
+                    "0",      # nice
+                    "0",      # num_threads
+                    "0",      # itrealvalue
+                    "6",      # starttime
+                    "0",      # vsize
+                    "0",      # rss
+                    "0",      # rsslim
+                    "0",      # startcode
+                    "0",      # endcode
+                    "0",      # startstack
+                    "0",      # kstkesp
+                    "0",      # kstkeip
+                    "0",      # signal
+                    "0",      # blocked
+                    "0",      # sigignore
+                    "0",      # sigcatch
+                    "0",      # wchan
+                    "0",      # nswap
+                    "0",      # cnswap
+                    "0",      # exit_signal
+                    "6",      # processor
+                ]
+                return io.BytesIO(" ".join(args).encode())
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock):
+            p = psutil.Process()
+            self.assertEqual(p.name(), 'cat')
+            self.assertEqual(p.status(), psutil.STATUS_ZOMBIE)
+            self.assertEqual(p.ppid(), 1)
+            self.assertEqual(
+                p.create_time(), 6 / CLOCK_TICKS + psutil.boot_time())
+            cpu = p.cpu_times()
+            self.assertEqual(cpu.user, 2 / CLOCK_TICKS)
+            self.assertEqual(cpu.system, 3 / CLOCK_TICKS)
+            self.assertEqual(cpu.children_user, 4 / CLOCK_TICKS)
+            self.assertEqual(cpu.children_system, 5 / CLOCK_TICKS)
+            self.assertEqual(p.cpu_num(), 6)
+
+    def test_status_file_parsing(self):
+        def open_mock(name, *args, **kwargs):
+            if name.startswith('/proc/%s/status' % os.getpid()):
+                return io.BytesIO(textwrap.dedent("""\
+                    Uid:\t1000\t1001\t1002\t1003
+                    Gid:\t1004\t1005\t1006\t1007
+                    Threads:\t66
+                    Cpus_allowed:\tf
+                    Cpus_allowed_list:\t0-7
+                    voluntary_ctxt_switches:\t12
+                    nonvoluntary_ctxt_switches:\t13""").encode())
+            else:
+                return orig_open(name, *args, **kwargs)
+
+        orig_open = open
+        patch_point = 'builtins.open' if PY3 else '__builtin__.open'
+        with mock.patch(patch_point, side_effect=open_mock):
+            p = psutil.Process()
+            self.assertEqual(p.num_ctx_switches().voluntary, 12)
+            self.assertEqual(p.num_ctx_switches().involuntary, 13)
+            self.assertEqual(p.num_threads(), 66)
+            uids = p.uids()
+            self.assertEqual(uids.real, 1000)
+            self.assertEqual(uids.effective, 1001)
+            self.assertEqual(uids.saved, 1002)
+            gids = p.gids()
+            self.assertEqual(gids.real, 1004)
+            self.assertEqual(gids.effective, 1005)
+            self.assertEqual(gids.saved, 1006)
+            self.assertEqual(p._proc._get_eligible_cpus(), list(range(0, 8)))
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestProcessAgainstStatus(unittest.TestCase):
+    """/proc/pid/stat and /proc/pid/status have many values in common.
+    Whenever possible, psutil uses /proc/pid/stat (it's faster).
+    For all those cases we check that the value found in
+    /proc/pid/stat (by psutil) matches the one found in
+    /proc/pid/status.
+    """
+
+    @classmethod
+    def setUpClass(cls):
+        cls.proc = psutil.Process()
+
+    def read_status_file(self, linestart):
+        with psutil._psplatform.open_text(
+                '/proc/%s/status' % self.proc.pid) as f:
+            for line in f:
+                line = line.strip()
+                if line.startswith(linestart):
+                    value = line.partition('\t')[2]
+                    try:
+                        return int(value)
+                    except ValueError:
+                        return value
+            raise ValueError("can't find %r" % linestart)
+
+    def test_name(self):
+        value = self.read_status_file("Name:")
+        self.assertEqual(self.proc.name(), value)
+
+    def test_status(self):
+        value = self.read_status_file("State:")
+        value = value[value.find('(') + 1:value.rfind(')')]
+        value = value.replace(' ', '-')
+        self.assertEqual(self.proc.status(), value)
+
+    def test_ppid(self):
+        value = self.read_status_file("PPid:")
+        self.assertEqual(self.proc.ppid(), value)
+
+    def test_num_threads(self):
+        value = self.read_status_file("Threads:")
+        self.assertEqual(self.proc.num_threads(), value)
+
+    def test_uids(self):
+        value = self.read_status_file("Uid:")
+        value = tuple(map(int, value.split()[1:4]))
+        self.assertEqual(self.proc.uids(), value)
+
+    def test_gids(self):
+        value = self.read_status_file("Gid:")
+        value = tuple(map(int, value.split()[1:4]))
+        self.assertEqual(self.proc.gids(), value)
+
+    @retry_before_failing()
+    def test_num_ctx_switches(self):
+        value = self.read_status_file("voluntary_ctxt_switches:")
+        self.assertEqual(self.proc.num_ctx_switches().voluntary, value)
+        value = self.read_status_file("nonvoluntary_ctxt_switches:")
+        self.assertEqual(self.proc.num_ctx_switches().involuntary, value)
+
+    def test_cpu_affinity(self):
+        value = self.read_status_file("Cpus_allowed_list:")
+        if '-' in str(value):
+            min_, max_ = map(int, value.split('-'))
+            self.assertEqual(
+                self.proc.cpu_affinity(), list(range(min_, max_ + 1)))
+
+    def test_cpu_affinity_eligible_cpus(self):
+        value = self.read_status_file("Cpus_allowed_list:")
+        with mock.patch("psutil._pslinux.per_cpu_times") as m:
+            self.proc._proc._get_eligible_cpus()
+        if '-' in str(value):
+            assert not m.called
+        else:
+            assert m.called
+
+
+# =====================================================================
+# --- test utils
+# =====================================================================
+
+
+@unittest.skipIf(not LINUX, "LINUX only")
+class TestUtils(unittest.TestCase):
+
+    def test_open_text(self):
+        with psutil._psplatform.open_text(__file__) as f:
+            self.assertEqual(f.mode, 'rt')
+
+    def test_open_binary(self):
+        with psutil._psplatform.open_binary(__file__) as f:
+            self.assertEqual(f.mode, 'rb')
+
+    def test_readlink(self):
+        with mock.patch("os.readlink", return_value="foo (deleted)") as m:
+            self.assertEqual(psutil._psplatform.readlink("bar"), "foo")
+            assert m.called
+
+    def test_cat(self):
+        fname = os.path.abspath(TESTFN)
+        with open(fname, "wt") as f:
+            f.write("foo ")
+        self.assertEqual(psutil._psplatform.cat(TESTFN, binary=False), "foo")
+        self.assertEqual(psutil._psplatform.cat(TESTFN, binary=True), b"foo")
+        self.assertEqual(
+            psutil._psplatform.cat(TESTFN + '??', fallback="bar"), "bar")
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_memory_leaks.py b/psutil/tests/test_memory_leaks.py
new file mode 100755
index 00000000..680fe780
--- /dev/null
+++ b/psutil/tests/test_memory_leaks.py
@@ -0,0 +1,599 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Tests for detecting function memory leaks (typically the ones
+implemented in C). It does so by calling a function many times and
+checking whether process memory usage keeps increasing between
+calls or over time.
+Note that this may produce false positives (especially on Windows
+for some reason).
+"""
+
+from __future__ import print_function
+import errno
+import functools
+import gc
+import os
+import sys
+import threading
+import time
+
+import psutil
+import psutil._common
+from psutil import LINUX
+from psutil import OPENBSD
+from psutil import OSX
+from psutil import POSIX
+from psutil import SUNOS
+from psutil import WINDOWS
+from psutil._compat import xrange
+from psutil.tests import create_sockets
+from psutil.tests import get_test_subprocess
+from psutil.tests import HAS_CPU_AFFINITY
+from psutil.tests import HAS_CPU_FREQ
+from psutil.tests import HAS_ENVIRON
+from psutil.tests import HAS_IONICE
+from psutil.tests import HAS_MEMORY_MAPS
+from psutil.tests import HAS_PROC_CPU_NUM
+from psutil.tests import HAS_PROC_IO_COUNTERS
+from psutil.tests import HAS_RLIMIT
+from psutil.tests import HAS_SENSORS_BATTERY
+from psutil.tests import HAS_SENSORS_FANS
+from psutil.tests import HAS_SENSORS_TEMPERATURES
+from psutil.tests import reap_children
+from psutil.tests import run_test_module_by_name
+from psutil.tests import safe_rmpath
+from psutil.tests import skip_on_access_denied
+from psutil.tests import TESTFN
+from psutil.tests import TRAVIS
+from psutil.tests import unittest
+
+
+LOOPS = 1000
+MEMORY_TOLERANCE = 4096
+RETRY_FOR = 3
+
+SKIP_PYTHON_IMPL = True if TRAVIS else False
+cext = psutil._psplatform.cext
+thisproc = psutil.Process()
+SKIP_PYTHON_IMPL = True if TRAVIS else False
+
+
+# ===================================================================
+# utils
+# ===================================================================
+
+
+def skip_if_linux():
+    return unittest.skipIf(LINUX and SKIP_PYTHON_IMPL,
+                           "worthless on LINUX (pure python)")
+
+
+def bytes2human(n):
+    """
+    http://code.activestate.com/recipes/578019
+    >>> bytes2human(10000)
+    '9.8K'
+    >>> bytes2human(100001221)
+    '95.4M'
+    """
+    symbols = ('K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y')
+    prefix = {}
+    for i, s in enumerate(symbols):
+        prefix[s] = 1 << (i + 1) * 10
+    for s in reversed(symbols):
+        if n >= prefix[s]:
+            value = float(n) / prefix[s]
+            return '%.2f%s' % (value, s)
+    return "%sB" % n
+
+
+class TestMemLeak(unittest.TestCase):
+    """Base framework class which calls a function many times and
+    produces a failure if process memory usage keeps increasing
+    between calls or over time.
+    """
+    tolerance = MEMORY_TOLERANCE
+    loops = LOOPS
+    retry_for = RETRY_FOR
+
+    def setUp(self):
+        gc.collect()
+
+    def execute(self, fun, *args, **kwargs):
+        """Test a callable."""
+        def call_many_times():
+            for x in xrange(loops):
+                self._call(fun, *args, **kwargs)
+            del x
+            gc.collect()
+
+        tolerance = kwargs.pop('tolerance_', None) or self.tolerance
+        loops = kwargs.pop('loops_', None) or self.loops
+        retry_for = kwargs.pop('retry_for_', None) or self.retry_for
+
+        # warm up
+        for x in range(10):
+            self._call(fun, *args, **kwargs)
+        self.assertEqual(gc.garbage, [])
+        self.assertEqual(threading.active_count(), 1)
+        self.assertEqual(thisproc.children(), [])
+
+        # Get 2 distinct memory samples, before and after having
+        # called fun repeadetly.
+        # step 1
+        call_many_times()
+        mem1 = self._get_mem()
+        # step 2
+        call_many_times()
+        mem2 = self._get_mem()
+
+        diff1 = mem2 - mem1
+        if diff1 > tolerance:
+            # This doesn't necessarily mean we have a leak yet.
+            # At this point we assume that after having called the
+            # function so many times the memory usage is stabilized
+            # and if there are no leaks it should not increase
+            # anymore.
+            # Let's keep calling fun for 3 more seconds and fail if
+            # we notice any difference.
+            ncalls = 0
+            stop_at = time.time() + retry_for
+            while time.time() <= stop_at:
+                self._call(fun, *args, **kwargs)
+                ncalls += 1
+
+            del stop_at
+            gc.collect()
+            mem3 = self._get_mem()
+            diff2 = mem3 - mem2
+
+            if mem3 > mem2:
+                # failure
+                extra_proc_mem = bytes2human(diff1 + diff2)
+                print("exta proc mem: %s" % extra_proc_mem, file=sys.stderr)
+                msg = "+%s after %s calls, +%s after another %s calls, "
+                msg += "+%s extra proc mem"
+                msg = msg % (
+                    bytes2human(diff1), loops, bytes2human(diff2), ncalls,
+                    extra_proc_mem)
+                self.fail(msg)
+
+    def execute_w_exc(self, exc, fun, *args, **kwargs):
+        """Convenience function which tests a callable raising
+        an exception.
+        """
+        def call():
+            self.assertRaises(exc, fun, *args, **kwargs)
+
+        self.execute(call)
+
+    @staticmethod
+    def _get_mem():
+        # By using USS memory it seems it's less likely to bump
+        # into false positives.
+        if LINUX or WINDOWS or OSX:
+            return thisproc.memory_full_info().uss
+        else:
+            return thisproc.memory_info().rss
+
+    @staticmethod
+    def _call(fun, *args, **kwargs):
+        fun(*args, **kwargs)
+
+
+# ===================================================================
+# Process class
+# ===================================================================
+
+
+class TestProcessObjectLeaks(TestMemLeak):
+    """Test leaks of Process class methods."""
+
+    proc = thisproc
+
+    def test_coverage(self):
+        skip = set((
+            "pid", "as_dict", "children", "cpu_affinity", "cpu_percent",
+            "ionice", "is_running", "kill", "memory_info_ex", "memory_percent",
+            "nice", "oneshot", "parent", "rlimit", "send_signal", "suspend",
+            "terminate", "wait"))
+        for name in dir(psutil.Process):
+            if name.startswith('_'):
+                continue
+            if name in skip:
+                continue
+            self.assertTrue(hasattr(self, "test_" + name), msg=name)
+
+    @skip_if_linux()
+    def test_name(self):
+        self.execute(self.proc.name)
+
+    @skip_if_linux()
+    def test_cmdline(self):
+        self.execute(self.proc.cmdline)
+
+    @skip_if_linux()
+    def test_exe(self):
+        self.execute(self.proc.exe)
+
+    @skip_if_linux()
+    def test_ppid(self):
+        self.execute(self.proc.ppid)
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    @skip_if_linux()
+    def test_uids(self):
+        self.execute(self.proc.uids)
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    @skip_if_linux()
+    def test_gids(self):
+        self.execute(self.proc.gids)
+
+    @skip_if_linux()
+    def test_status(self):
+        self.execute(self.proc.status)
+
+    def test_nice_get(self):
+        self.execute(self.proc.nice)
+
+    def test_nice_set(self):
+        niceness = thisproc.nice()
+        self.execute(self.proc.nice, niceness)
+
+    @unittest.skipIf(not HAS_IONICE, "not supported")
+    def test_ionice_get(self):
+        self.execute(self.proc.ionice)
+
+    @unittest.skipIf(not HAS_IONICE, "not supported")
+    def test_ionice_set(self):
+        if WINDOWS:
+            value = thisproc.ionice()
+            self.execute(self.proc.ionice, value)
+        else:
+            self.execute(self.proc.ionice, psutil.IOPRIO_CLASS_NONE)
+            fun = functools.partial(cext.proc_ioprio_set, os.getpid(), -1, 0)
+            self.execute_w_exc(OSError, fun)
+
+    @unittest.skipIf(not HAS_PROC_IO_COUNTERS, "not supported")
+    @skip_if_linux()
+    def test_io_counters(self):
+        self.execute(self.proc.io_counters)
+
+    @unittest.skipIf(POSIX, "worthless on POSIX")
+    def test_username(self):
+        self.execute(self.proc.username)
+
+    @skip_if_linux()
+    def test_create_time(self):
+        self.execute(self.proc.create_time)
+
+    @skip_if_linux()
+    @skip_on_access_denied(only_if=OPENBSD)
+    def test_num_threads(self):
+        self.execute(self.proc.num_threads)
+
+    @unittest.skipIf(not WINDOWS, "WINDOWS only")
+    def test_num_handles(self):
+        self.execute(self.proc.num_handles)
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    @skip_if_linux()
+    def test_num_fds(self):
+        self.execute(self.proc.num_fds)
+
+    @skip_if_linux()
+    def test_num_ctx_switches(self):
+        self.execute(self.proc.num_ctx_switches)
+
+    @skip_if_linux()
+    @skip_on_access_denied(only_if=OPENBSD)
+    def test_threads(self):
+        self.execute(self.proc.threads)
+
+    @skip_if_linux()
+    def test_cpu_times(self):
+        self.execute(self.proc.cpu_times)
+
+    @skip_if_linux()
+    @unittest.skipIf(not HAS_PROC_CPU_NUM, "not supported")
+    def test_cpu_num(self):
+        self.execute(self.proc.cpu_num)
+
+    @skip_if_linux()
+    def test_memory_info(self):
+        self.execute(self.proc.memory_info)
+
+    @skip_if_linux()
+    def test_memory_full_info(self):
+        self.execute(self.proc.memory_full_info)
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    @skip_if_linux()
+    def test_terminal(self):
+        self.execute(self.proc.terminal)
+
+    @unittest.skipIf(POSIX and SKIP_PYTHON_IMPL,
+                     "worthless on POSIX (pure python)")
+    def test_resume(self):
+        self.execute(self.proc.resume)
+
+    @skip_if_linux()
+    def test_cwd(self):
+        self.execute(self.proc.cwd)
+
+    @unittest.skipIf(not HAS_CPU_AFFINITY, "not supported")
+    def test_cpu_affinity_get(self):
+        self.execute(self.proc.cpu_affinity)
+
+    @unittest.skipIf(not HAS_CPU_AFFINITY, "not supported")
+    def test_cpu_affinity_set(self):
+        affinity = thisproc.cpu_affinity()
+        self.execute(self.proc.cpu_affinity, affinity)
+        if not TRAVIS:
+            self.execute_w_exc(ValueError, self.proc.cpu_affinity, [-1])
+
+    @skip_if_linux()
+    def test_open_files(self):
+        safe_rmpath(TESTFN)  # needed after UNIX socket test has run
+        with open(TESTFN, 'w'):
+            self.execute(self.proc.open_files)
+
+    # OSX implementation is unbelievably slow
+    @unittest.skipIf(OSX, "too slow on OSX")
+    @unittest.skipIf(not HAS_MEMORY_MAPS, "not supported")
+    @skip_if_linux()
+    def test_memory_maps(self):
+        self.execute(self.proc.memory_maps)
+
+    @unittest.skipIf(not LINUX, "LINUX only")
+    @unittest.skipIf(not HAS_RLIMIT, "not supported")
+    def test_rlimit_get(self):
+        self.execute(self.proc.rlimit, psutil.RLIMIT_NOFILE)
+
+    @unittest.skipIf(not LINUX, "LINUX only")
+    @unittest.skipIf(not HAS_RLIMIT, "not supported")
+    def test_rlimit_set(self):
+        limit = thisproc.rlimit(psutil.RLIMIT_NOFILE)
+        self.execute(self.proc.rlimit, psutil.RLIMIT_NOFILE, limit)
+        self.execute_w_exc(OSError, self.proc.rlimit, -1)
+
+    @skip_if_linux()
+    # Windows implementation is based on a single system-wide
+    # function (tested later).
+    @unittest.skipIf(WINDOWS, "worthless on WINDOWS")
+    def test_connections(self):
+        # TODO: UNIX sockets are temporarily implemented by parsing
+        # 'pfiles' cmd  output; we don't want that part of the code to
+        # be executed.
+        with create_sockets():
+            kind = 'inet' if SUNOS else 'all'
+            self.execute(self.proc.connections, kind)
+
+    @unittest.skipIf(not HAS_ENVIRON, "not supported")
+    def test_environ(self):
+        self.execute(self.proc.environ)
+
+    @unittest.skipIf(not WINDOWS, "WINDOWS only")
+    def test_proc_info(self):
+        self.execute(cext.proc_info, os.getpid())
+
+
+class TestTerminatedProcessLeaks(TestProcessObjectLeaks):
+    """Repeat the tests above looking for leaks occurring when dealing
+    with terminated processes raising NoSuchProcess exception.
+    The C functions are still invoked but will follow different code
+    paths. We'll check those code paths.
+    """
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestTerminatedProcessLeaks, cls).setUpClass()
+        p = get_test_subprocess()
+        cls.proc = psutil.Process(p.pid)
+        cls.proc.kill()
+        cls.proc.wait()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestTerminatedProcessLeaks, cls).tearDownClass()
+        reap_children()
+
+    def _call(self, fun, *args, **kwargs):
+        try:
+            fun(*args, **kwargs)
+        except psutil.NoSuchProcess:
+            pass
+
+    if WINDOWS:
+
+        def test_kill(self):
+            self.execute(self.proc.kill)
+
+        def test_terminate(self):
+            self.execute(self.proc.terminate)
+
+        def test_suspend(self):
+            self.execute(self.proc.suspend)
+
+        def test_resume(self):
+            self.execute(self.proc.resume)
+
+        def test_wait(self):
+            self.execute(self.proc.wait)
+
+        def test_proc_info(self):
+            # test dual implementation
+            def call():
+                try:
+                    return cext.proc_info(self.proc.pid)
+                except OSError as err:
+                    if err.errno != errno.ESRCH:
+                        raise
+
+            self.execute(call)
+
+
+# ===================================================================
+# system APIs
+# ===================================================================
+
+
+class TestModuleFunctionsLeaks(TestMemLeak):
+    """Test leaks of psutil module functions."""
+
+    def test_coverage(self):
+        skip = set((
+            "version_info", "__version__", "process_iter", "wait_procs",
+            "cpu_percent", "cpu_times_percent", "cpu_count"))
+        for name in psutil.__all__:
+            if not name.islower():
+                continue
+            if name in skip:
+                continue
+            self.assertTrue(hasattr(self, "test_" + name), msg=name)
+
+    # --- cpu
+
+    @skip_if_linux()
+    def test_cpu_count_logical(self):
+        self.execute(psutil.cpu_count, logical=True)
+
+    @skip_if_linux()
+    def test_cpu_count_physical(self):
+        self.execute(psutil.cpu_count, logical=False)
+
+    @skip_if_linux()
+    def test_cpu_times(self):
+        self.execute(psutil.cpu_times)
+
+    @skip_if_linux()
+    def test_per_cpu_times(self):
+        self.execute(psutil.cpu_times, percpu=True)
+
+    def test_cpu_stats(self):
+        self.execute(psutil.cpu_stats)
+
+    @skip_if_linux()
+    @unittest.skipIf(not HAS_CPU_FREQ, "not supported")
+    def test_cpu_freq(self):
+        self.execute(psutil.cpu_freq)
+
+    # --- mem
+
+    def test_virtual_memory(self):
+        self.execute(psutil.virtual_memory)
+
+    # TODO: remove this skip when this gets fixed
+    @unittest.skipIf(SUNOS,
+                     "worthless on SUNOS (uses a subprocess)")
+    def test_swap_memory(self):
+        self.execute(psutil.swap_memory)
+
+    @unittest.skipIf(POSIX and SKIP_PYTHON_IMPL,
+                     "worthless on POSIX (pure python)")
+    def test_pid_exists(self):
+        self.execute(psutil.pid_exists, os.getpid())
+
+    # --- disk
+
+    @unittest.skipIf(POSIX and SKIP_PYTHON_IMPL,
+                     "worthless on POSIX (pure python)")
+    def test_disk_usage(self):
+        self.execute(psutil.disk_usage, '.')
+
+    def test_disk_partitions(self):
+        self.execute(psutil.disk_partitions)
+
+    @unittest.skipIf(LINUX and not os.path.exists('/proc/diskstats'),
+                     '/proc/diskstats not available on this Linux version')
+    @skip_if_linux()
+    def test_disk_io_counters(self):
+        self.execute(psutil.disk_io_counters, nowrap=False)
+
+    # --- proc
+
+    @skip_if_linux()
+    def test_pids(self):
+        self.execute(psutil.pids)
+
+    # --- net
+
+    @skip_if_linux()
+    def test_net_io_counters(self):
+        self.execute(psutil.net_io_counters, nowrap=False)
+
+    @unittest.skipIf(LINUX,
+                     "worthless on Linux (pure python)")
+    @unittest.skipIf(OSX and os.getuid() != 0, "need root access")
+    def test_net_connections(self):
+        with create_sockets():
+            self.execute(psutil.net_connections)
+
+    def test_net_if_addrs(self):
+        # Note: verified that on Windows this was a false positive.
+        self.execute(psutil.net_if_addrs,
+                     tolerance_=80 * 1024 if WINDOWS else None)
+
+    @unittest.skipIf(TRAVIS, "EPERM on travis")
+    def test_net_if_stats(self):
+        self.execute(psutil.net_if_stats)
+
+    # --- sensors
+
+    @skip_if_linux()
+    @unittest.skipIf(not HAS_SENSORS_BATTERY, "not supported")
+    def test_sensors_battery(self):
+        self.execute(psutil.sensors_battery)
+
+    @skip_if_linux()
+    @unittest.skipIf(not HAS_SENSORS_TEMPERATURES, "not supported")
+    def test_sensors_temperatures(self):
+        self.execute(psutil.sensors_temperatures)
+
+    @skip_if_linux()
+    @unittest.skipIf(not HAS_SENSORS_FANS, "not supported")
+    def test_sensors_fans(self):
+        self.execute(psutil.sensors_fans)
+
+    # --- others
+
+    @skip_if_linux()
+    def test_boot_time(self):
+        self.execute(psutil.boot_time)
+
+    # XXX - on Windows this produces a false positive
+    @unittest.skipIf(WINDOWS, "XXX produces a false positive on Windows")
+    def test_users(self):
+        self.execute(psutil.users)
+
+    if WINDOWS:
+
+        # --- win services
+
+        def test_win_service_iter(self):
+            self.execute(cext.winservice_enumerate)
+
+        def test_win_service_get(self):
+            pass
+
+        def test_win_service_get_config(self):
+            name = next(psutil.win_service_iter()).name()
+            self.execute(cext.winservice_query_config, name)
+
+        def test_win_service_get_status(self):
+            name = next(psutil.win_service_iter()).name()
+            self.execute(cext.winservice_query_status, name)
+
+        def test_win_service_get_description(self):
+            name = next(psutil.win_service_iter()).name()
+            self.execute(cext.winservice_query_descr, name)
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_misc.py b/psutil/tests/test_misc.py
new file mode 100755
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+++ b/psutil/tests/test_misc.py
@@ -0,0 +1,1046 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Miscellaneous tests.
+"""
+
+import ast
+import collections
+import contextlib
+import errno
+import json
+import os
+import pickle
+import socket
+import stat
+
+from psutil import LINUX
+from psutil import POSIX
+from psutil import WINDOWS
+from psutil._common import memoize
+from psutil._common import memoize_when_activated
+from psutil._common import supports_ipv6
+from psutil._common import wrap_numbers
+from psutil._compat import PY3
+from psutil.tests import APPVEYOR
+from psutil.tests import bind_socket
+from psutil.tests import bind_unix_socket
+from psutil.tests import call_until
+from psutil.tests import chdir
+from psutil.tests import create_proc_children_pair
+from psutil.tests import create_sockets
+from psutil.tests import create_zombie_proc
+from psutil.tests import DEVNULL
+from psutil.tests import get_free_port
+from psutil.tests import get_test_subprocess
+from psutil.tests import HAS_BATTERY
+from psutil.tests import HAS_CONNECTIONS_UNIX
+from psutil.tests import HAS_MEMORY_FULL_INFO
+from psutil.tests import HAS_MEMORY_MAPS
+from psutil.tests import HAS_SENSORS_BATTERY
+from psutil.tests import HAS_SENSORS_FANS
+from psutil.tests import HAS_SENSORS_TEMPERATURES
+from psutil.tests import import_module_by_path
+from psutil.tests import is_namedtuple
+from psutil.tests import mock
+from psutil.tests import PYTHON_EXE
+from psutil.tests import reap_children
+from psutil.tests import reload_module
+from psutil.tests import retry
+from psutil.tests import ROOT_DIR
+from psutil.tests import run_test_module_by_name
+from psutil.tests import safe_mkdir
+from psutil.tests import safe_rmpath
+from psutil.tests import SCRIPTS_DIR
+from psutil.tests import sh
+from psutil.tests import tcp_socketpair
+from psutil.tests import TESTFN
+from psutil.tests import TOX
+from psutil.tests import TRAVIS
+from psutil.tests import unittest
+from psutil.tests import unix_socket_path
+from psutil.tests import unix_socketpair
+from psutil.tests import wait_for_file
+from psutil.tests import wait_for_pid
+import psutil
+import psutil.tests
+
+
+# ===================================================================
+# --- Misc / generic tests.
+# ===================================================================
+
+
+class TestMisc(unittest.TestCase):
+
+    def test_process__repr__(self, func=repr):
+        p = psutil.Process()
+        r = func(p)
+        self.assertIn("psutil.Process", r)
+        self.assertIn("pid=%s" % p.pid, r)
+        self.assertIn("name=", r)
+        self.assertIn(p.name(), r)
+        with mock.patch.object(psutil.Process, "name",
+                               side_effect=psutil.ZombieProcess(os.getpid())):
+            p = psutil.Process()
+            r = func(p)
+            self.assertIn("pid=%s" % p.pid, r)
+            self.assertIn("zombie", r)
+            self.assertNotIn("name=", r)
+        with mock.patch.object(psutil.Process, "name",
+                               side_effect=psutil.NoSuchProcess(os.getpid())):
+            p = psutil.Process()
+            r = func(p)
+            self.assertIn("pid=%s" % p.pid, r)
+            self.assertIn("terminated", r)
+            self.assertNotIn("name=", r)
+        with mock.patch.object(psutil.Process, "name",
+                               side_effect=psutil.AccessDenied(os.getpid())):
+            p = psutil.Process()
+            r = func(p)
+            self.assertIn("pid=%s" % p.pid, r)
+            self.assertNotIn("name=", r)
+
+    def test_process__str__(self):
+        self.test_process__repr__(func=str)
+
+    def test_no_such_process__repr__(self, func=repr):
+        self.assertEqual(
+            repr(psutil.NoSuchProcess(321)),
+            "psutil.NoSuchProcess process no longer exists (pid=321)")
+        self.assertEqual(
+            repr(psutil.NoSuchProcess(321, name='foo')),
+            "psutil.NoSuchProcess process no longer exists (pid=321, "
+            "name='foo')")
+        self.assertEqual(
+            repr(psutil.NoSuchProcess(321, msg='foo')),
+            "psutil.NoSuchProcess foo")
+
+    def test_zombie_process__repr__(self, func=repr):
+        self.assertEqual(
+            repr(psutil.ZombieProcess(321)),
+            "psutil.ZombieProcess process still exists but it's a zombie "
+            "(pid=321)")
+        self.assertEqual(
+            repr(psutil.ZombieProcess(321, name='foo')),
+            "psutil.ZombieProcess process still exists but it's a zombie "
+            "(pid=321, name='foo')")
+        self.assertEqual(
+            repr(psutil.ZombieProcess(321, name='foo', ppid=1)),
+            "psutil.ZombieProcess process still exists but it's a zombie "
+            "(pid=321, name='foo', ppid=1)")
+        self.assertEqual(
+            repr(psutil.ZombieProcess(321, msg='foo')),
+            "psutil.ZombieProcess foo")
+
+    def test_access_denied__repr__(self, func=repr):
+        self.assertEqual(
+            repr(psutil.AccessDenied(321)),
+            "psutil.AccessDenied (pid=321)")
+        self.assertEqual(
+            repr(psutil.AccessDenied(321, name='foo')),
+            "psutil.AccessDenied (pid=321, name='foo')")
+        self.assertEqual(
+            repr(psutil.AccessDenied(321, msg='foo')),
+            "psutil.AccessDenied foo")
+
+    def test_timeout_expired__repr__(self, func=repr):
+        self.assertEqual(
+            repr(psutil.TimeoutExpired(321)),
+            "psutil.TimeoutExpired timeout after 321 seconds")
+        self.assertEqual(
+            repr(psutil.TimeoutExpired(321, pid=111)),
+            "psutil.TimeoutExpired timeout after 321 seconds (pid=111)")
+        self.assertEqual(
+            repr(psutil.TimeoutExpired(321, pid=111, name='foo')),
+            "psutil.TimeoutExpired timeout after 321 seconds "
+            "(pid=111, name='foo')")
+
+    def test_process__eq__(self):
+        p1 = psutil.Process()
+        p2 = psutil.Process()
+        self.assertEqual(p1, p2)
+        p2._ident = (0, 0)
+        self.assertNotEqual(p1, p2)
+        self.assertNotEqual(p1, 'foo')
+
+    def test_process__hash__(self):
+        s = set([psutil.Process(), psutil.Process()])
+        self.assertEqual(len(s), 1)
+
+    def test__all__(self):
+        dir_psutil = dir(psutil)
+        for name in dir_psutil:
+            if name in ('callable', 'error', 'namedtuple', 'tests',
+                        'long', 'test', 'NUM_CPUS', 'BOOT_TIME',
+                        'TOTAL_PHYMEM'):
+                continue
+            if not name.startswith('_'):
+                try:
+                    __import__(name)
+                except ImportError:
+                    if name not in psutil.__all__:
+                        fun = getattr(psutil, name)
+                        if fun is None:
+                            continue
+                        if (fun.__doc__ is not None and
+                                'deprecated' not in fun.__doc__.lower()):
+                            self.fail('%r not in psutil.__all__' % name)
+
+        # Import 'star' will break if __all__ is inconsistent, see:
+        # https://github.com/giampaolo/psutil/issues/656
+        # Can't do `from psutil import *` as it won't work on python 3
+        # so we simply iterate over __all__.
+        for name in psutil.__all__:
+            self.assertIn(name, dir_psutil)
+
+    def test_version(self):
+        self.assertEqual('.'.join([str(x) for x in psutil.version_info]),
+                         psutil.__version__)
+
+    def test_process_as_dict_no_new_names(self):
+        # See https://github.com/giampaolo/psutil/issues/813
+        p = psutil.Process()
+        p.foo = '1'
+        self.assertNotIn('foo', p.as_dict())
+
+    def test_memoize(self):
+        @memoize
+        def foo(*args, **kwargs):
+            "foo docstring"
+            calls.append(None)
+            return (args, kwargs)
+
+        calls = []
+        # no args
+        for x in range(2):
+            ret = foo()
+            expected = ((), {})
+            self.assertEqual(ret, expected)
+            self.assertEqual(len(calls), 1)
+        # with args
+        for x in range(2):
+            ret = foo(1)
+            expected = ((1, ), {})
+            self.assertEqual(ret, expected)
+            self.assertEqual(len(calls), 2)
+        # with args + kwargs
+        for x in range(2):
+            ret = foo(1, bar=2)
+            expected = ((1, ), {'bar': 2})
+            self.assertEqual(ret, expected)
+            self.assertEqual(len(calls), 3)
+        # clear cache
+        foo.cache_clear()
+        ret = foo()
+        expected = ((), {})
+        self.assertEqual(ret, expected)
+        self.assertEqual(len(calls), 4)
+        # docstring
+        self.assertEqual(foo.__doc__, "foo docstring")
+
+    def test_memoize_when_activated(self):
+        class Foo:
+
+            @memoize_when_activated
+            def foo(self):
+                calls.append(None)
+
+        f = Foo()
+        calls = []
+        f.foo()
+        f.foo()
+        self.assertEqual(len(calls), 2)
+
+        # activate
+        calls = []
+        f.foo.cache_activate()
+        f.foo()
+        f.foo()
+        self.assertEqual(len(calls), 1)
+
+        # deactivate
+        calls = []
+        f.foo.cache_deactivate()
+        f.foo()
+        f.foo()
+        self.assertEqual(len(calls), 2)
+
+    def test_parse_environ_block(self):
+        from psutil._common import parse_environ_block
+
+        def k(s):
+            return s.upper() if WINDOWS else s
+
+        self.assertEqual(parse_environ_block("a=1\0"),
+                         {k("a"): "1"})
+        self.assertEqual(parse_environ_block("a=1\0b=2\0\0"),
+                         {k("a"): "1", k("b"): "2"})
+        self.assertEqual(parse_environ_block("a=1\0b=\0\0"),
+                         {k("a"): "1", k("b"): ""})
+        # ignore everything after \0\0
+        self.assertEqual(parse_environ_block("a=1\0b=2\0\0c=3\0"),
+                         {k("a"): "1", k("b"): "2"})
+        # ignore everything that is not an assignment
+        self.assertEqual(parse_environ_block("xxx\0a=1\0"), {k("a"): "1"})
+        self.assertEqual(parse_environ_block("a=1\0=b=2\0"), {k("a"): "1"})
+        # do not fail if the block is incomplete
+        self.assertEqual(parse_environ_block("a=1\0b=2"), {k("a"): "1"})
+
+    def test_supports_ipv6(self):
+        self.addCleanup(supports_ipv6.cache_clear)
+        if supports_ipv6():
+            with mock.patch('psutil._common.socket') as s:
+                s.has_ipv6 = False
+                supports_ipv6.cache_clear()
+                assert not supports_ipv6()
+
+            supports_ipv6.cache_clear()
+            with mock.patch('psutil._common.socket.socket',
+                            side_effect=socket.error) as s:
+                assert not supports_ipv6()
+                assert s.called
+
+            supports_ipv6.cache_clear()
+            with mock.patch('psutil._common.socket.socket',
+                            side_effect=socket.gaierror) as s:
+                assert not supports_ipv6()
+                supports_ipv6.cache_clear()
+                assert s.called
+
+            supports_ipv6.cache_clear()
+            with mock.patch('psutil._common.socket.socket.bind',
+                            side_effect=socket.gaierror) as s:
+                assert not supports_ipv6()
+                supports_ipv6.cache_clear()
+                assert s.called
+        else:
+            with self.assertRaises(Exception):
+                sock = socket.socket(socket.AF_INET6, socket.SOCK_STREAM)
+                sock.bind(("::1", 0))
+
+    def test_isfile_strict(self):
+        from psutil._common import isfile_strict
+        this_file = os.path.abspath(__file__)
+        assert isfile_strict(this_file)
+        assert not isfile_strict(os.path.dirname(this_file))
+        with mock.patch('psutil._common.os.stat',
+                        side_effect=OSError(errno.EPERM, "foo")):
+            self.assertRaises(OSError, isfile_strict, this_file)
+        with mock.patch('psutil._common.os.stat',
+                        side_effect=OSError(errno.EACCES, "foo")):
+            self.assertRaises(OSError, isfile_strict, this_file)
+        with mock.patch('psutil._common.os.stat',
+                        side_effect=OSError(errno.EINVAL, "foo")):
+            assert not isfile_strict(this_file)
+        with mock.patch('psutil._common.stat.S_ISREG', return_value=False):
+            assert not isfile_strict(this_file)
+
+    def test_serialization(self):
+        def check(ret):
+            if json is not None:
+                json.loads(json.dumps(ret))
+            a = pickle.dumps(ret)
+            b = pickle.loads(a)
+            self.assertEqual(ret, b)
+
+        check(psutil.Process().as_dict())
+        check(psutil.virtual_memory())
+        check(psutil.swap_memory())
+        check(psutil.cpu_times())
+        check(psutil.cpu_times_percent(interval=0))
+        check(psutil.net_io_counters())
+        if LINUX and not os.path.exists('/proc/diskstats'):
+            pass
+        else:
+            if not APPVEYOR:
+                check(psutil.disk_io_counters())
+        check(psutil.disk_partitions())
+        check(psutil.disk_usage(os.getcwd()))
+        check(psutil.users())
+
+    def test_setup_script(self):
+        setup_py = os.path.join(ROOT_DIR, 'setup.py')
+        if TRAVIS and not os.path.exists(setup_py):
+            return self.skipTest("can't find setup.py")
+        module = import_module_by_path(setup_py)
+        self.assertRaises(SystemExit, module.setup)
+        self.assertEqual(module.get_version(), psutil.__version__)
+
+    def test_ad_on_process_creation(self):
+        # We are supposed to be able to instantiate Process also in case
+        # of zombie processes or access denied.
+        with mock.patch.object(psutil.Process, 'create_time',
+                               side_effect=psutil.AccessDenied) as meth:
+            psutil.Process()
+            assert meth.called
+        with mock.patch.object(psutil.Process, 'create_time',
+                               side_effect=psutil.ZombieProcess(1)) as meth:
+            psutil.Process()
+            assert meth.called
+        with mock.patch.object(psutil.Process, 'create_time',
+                               side_effect=ValueError) as meth:
+            with self.assertRaises(ValueError):
+                psutil.Process()
+            assert meth.called
+
+    def test_sanity_version_check(self):
+        # see: https://github.com/giampaolo/psutil/issues/564
+        with mock.patch(
+                "psutil._psplatform.cext.version", return_value="0.0.0"):
+            with self.assertRaises(ImportError) as cm:
+                reload_module(psutil)
+            self.assertIn("version conflict", str(cm.exception).lower())
+
+
+# ===================================================================
+# --- Tests for wrap_numbers() function.
+# ===================================================================
+
+
+nt = collections.namedtuple('foo', 'a b c')
+
+
+class TestWrapNumbers(unittest.TestCase):
+
+    def setUp(self):
+        wrap_numbers.cache_clear()
+
+    tearDown = setUp
+
+    def test_first_call(self):
+        input = {'disk1': nt(5, 5, 5)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+
+    def test_input_hasnt_changed(self):
+        input = {'disk1': nt(5, 5, 5)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+
+    def test_increase_but_no_wrap(self):
+        input = {'disk1': nt(5, 5, 5)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        input = {'disk1': nt(10, 15, 20)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        input = {'disk1': nt(20, 25, 30)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        input = {'disk1': nt(20, 25, 30)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+
+    def test_wrap(self):
+        # let's say 100 is the threshold
+        input = {'disk1': nt(100, 100, 100)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        # first wrap restarts from 10
+        input = {'disk1': nt(100, 100, 10)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(100, 100, 110)})
+        # then it remains the same
+        input = {'disk1': nt(100, 100, 10)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(100, 100, 110)})
+        # then it goes up
+        input = {'disk1': nt(100, 100, 90)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(100, 100, 190)})
+        # then it wraps again
+        input = {'disk1': nt(100, 100, 20)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(100, 100, 210)})
+        # and remains the same
+        input = {'disk1': nt(100, 100, 20)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(100, 100, 210)})
+        # now wrap another num
+        input = {'disk1': nt(50, 100, 20)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(150, 100, 210)})
+        # and again
+        input = {'disk1': nt(40, 100, 20)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(190, 100, 210)})
+        # keep it the same
+        input = {'disk1': nt(40, 100, 20)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(190, 100, 210)})
+
+    def test_changing_keys(self):
+        # Emulate a case where the second call to disk_io()
+        # (or whatever) provides a new disk, then the new disk
+        # disappears on the third call.
+        input = {'disk1': nt(5, 5, 5)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        input = {'disk1': nt(5, 5, 5),
+                 'disk2': nt(7, 7, 7)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        input = {'disk1': nt(8, 8, 8)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+
+    def test_changing_keys_w_wrap(self):
+        input = {'disk1': nt(50, 50, 50),
+                 'disk2': nt(100, 100, 100)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        # disk 2 wraps
+        input = {'disk1': nt(50, 50, 50),
+                 'disk2': nt(100, 100, 10)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(50, 50, 50),
+                          'disk2': nt(100, 100, 110)})
+        # disk 2 disappears
+        input = {'disk1': nt(50, 50, 50)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+
+        # then it appears again; the old wrap is supposed to be
+        # gone.
+        input = {'disk1': nt(50, 50, 50),
+                 'disk2': nt(100, 100, 100)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        # remains the same
+        input = {'disk1': nt(50, 50, 50),
+                 'disk2': nt(100, 100, 100)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'), input)
+        # and then wraps again
+        input = {'disk1': nt(50, 50, 50),
+                 'disk2': nt(100, 100, 10)}
+        self.assertEqual(wrap_numbers(input, 'disk_io'),
+                         {'disk1': nt(50, 50, 50),
+                          'disk2': nt(100, 100, 110)})
+
+    def test_real_data(self):
+        d = {'nvme0n1': (300, 508, 640, 1571, 5970, 1987, 2049, 451751, 47048),
+             'nvme0n1p1': (1171, 2, 5600256, 1024, 516, 0, 0, 0, 8),
+             'nvme0n1p2': (54, 54, 2396160, 5165056, 4, 24, 30, 1207, 28),
+             'nvme0n1p3': (2389, 4539, 5154, 150, 4828, 1844, 2019, 398, 348)}
+        self.assertEqual(wrap_numbers(d, 'disk_io'), d)
+        self.assertEqual(wrap_numbers(d, 'disk_io'), d)
+        # decrease this   ↓
+        d = {'nvme0n1': (100, 508, 640, 1571, 5970, 1987, 2049, 451751, 47048),
+             'nvme0n1p1': (1171, 2, 5600256, 1024, 516, 0, 0, 0, 8),
+             'nvme0n1p2': (54, 54, 2396160, 5165056, 4, 24, 30, 1207, 28),
+             'nvme0n1p3': (2389, 4539, 5154, 150, 4828, 1844, 2019, 398, 348)}
+        out = wrap_numbers(d, 'disk_io')
+        self.assertEqual(out['nvme0n1'][0], 400)
+
+    # --- cache tests
+
+    def test_cache_first_call(self):
+        input = {'disk1': nt(5, 5, 5)}
+        wrap_numbers(input, 'disk_io')
+        cache = wrap_numbers.cache_info()
+        self.assertEqual(cache[0], {'disk_io': input})
+        self.assertEqual(cache[1], {'disk_io': {}})
+        self.assertEqual(cache[2], {'disk_io': {}})
+
+    def test_cache_call_twice(self):
+        input = {'disk1': nt(5, 5, 5)}
+        wrap_numbers(input, 'disk_io')
+        input = {'disk1': nt(10, 10, 10)}
+        wrap_numbers(input, 'disk_io')
+        cache = wrap_numbers.cache_info()
+        self.assertEqual(cache[0], {'disk_io': input})
+        self.assertEqual(
+            cache[1],
+            {'disk_io': {('disk1', 0): 0, ('disk1', 1): 0, ('disk1', 2): 0}})
+        self.assertEqual(cache[2], {'disk_io': {}})
+
+    def test_cache_wrap(self):
+        # let's say 100 is the threshold
+        input = {'disk1': nt(100, 100, 100)}
+        wrap_numbers(input, 'disk_io')
+
+        # first wrap restarts from 10
+        input = {'disk1': nt(100, 100, 10)}
+        wrap_numbers(input, 'disk_io')
+        cache = wrap_numbers.cache_info()
+        self.assertEqual(cache[0], {'disk_io': input})
+        self.assertEqual(
+            cache[1],
+            {'disk_io': {('disk1', 0): 0, ('disk1', 1): 0, ('disk1', 2): 100}})
+        self.assertEqual(cache[2], {'disk_io': {'disk1': set([('disk1', 2)])}})
+
+        def assert_():
+            cache = wrap_numbers.cache_info()
+            self.assertEqual(
+                cache[1],
+                {'disk_io': {('disk1', 0): 0, ('disk1', 1): 0,
+                             ('disk1', 2): 100}})
+            self.assertEqual(cache[2],
+                             {'disk_io': {'disk1': set([('disk1', 2)])}})
+
+        # then it remains the same
+        input = {'disk1': nt(100, 100, 10)}
+        wrap_numbers(input, 'disk_io')
+        cache = wrap_numbers.cache_info()
+        self.assertEqual(cache[0], {'disk_io': input})
+        assert_()
+
+        # then it goes up
+        input = {'disk1': nt(100, 100, 90)}
+        wrap_numbers(input, 'disk_io')
+        cache = wrap_numbers.cache_info()
+        self.assertEqual(cache[0], {'disk_io': input})
+        assert_()
+
+        # then it wraps again
+        input = {'disk1': nt(100, 100, 20)}
+        wrap_numbers(input, 'disk_io')
+        cache = wrap_numbers.cache_info()
+        self.assertEqual(cache[0], {'disk_io': input})
+        self.assertEqual(
+            cache[1],
+            {'disk_io': {('disk1', 0): 0, ('disk1', 1): 0, ('disk1', 2): 190}})
+        self.assertEqual(cache[2], {'disk_io': {'disk1': set([('disk1', 2)])}})
+
+    def test_cache_changing_keys(self):
+        input = {'disk1': nt(5, 5, 5)}
+        wrap_numbers(input, 'disk_io')
+        input = {'disk1': nt(5, 5, 5),
+                 'disk2': nt(7, 7, 7)}
+        wrap_numbers(input, 'disk_io')
+        cache = wrap_numbers.cache_info()
+        self.assertEqual(cache[0], {'disk_io': input})
+        self.assertEqual(
+            cache[1],
+            {'disk_io': {('disk1', 0): 0, ('disk1', 1): 0, ('disk1', 2): 0}})
+        self.assertEqual(cache[2], {'disk_io': {}})
+
+    def test_cache_clear(self):
+        input = {'disk1': nt(5, 5, 5)}
+        wrap_numbers(input, 'disk_io')
+        wrap_numbers(input, 'disk_io')
+        wrap_numbers.cache_clear('disk_io')
+        self.assertEqual(wrap_numbers.cache_info(), ({}, {}, {}))
+        wrap_numbers.cache_clear('disk_io')
+        wrap_numbers.cache_clear('?!?')
+
+    @unittest.skipIf(
+        not psutil.disk_io_counters() or not psutil.net_io_counters(),
+        "no disks or NICs available")
+    def test_cache_clear_public_apis(self):
+        psutil.disk_io_counters()
+        psutil.net_io_counters()
+        caches = wrap_numbers.cache_info()
+        for cache in caches:
+            self.assertIn('psutil.disk_io_counters', cache)
+            self.assertIn('psutil.net_io_counters', cache)
+
+        psutil.disk_io_counters.cache_clear()
+        caches = wrap_numbers.cache_info()
+        for cache in caches:
+            self.assertIn('psutil.net_io_counters', cache)
+            self.assertNotIn('psutil.disk_io_counters', cache)
+
+        psutil.net_io_counters.cache_clear()
+        caches = wrap_numbers.cache_info()
+        self.assertEqual(caches, ({}, {}, {}))
+
+
+# ===================================================================
+# --- Example script tests
+# ===================================================================
+
+
+@unittest.skipIf(TOX, "can't test on TOX")
+# See: https://travis-ci.org/giampaolo/psutil/jobs/295224806
+@unittest.skipIf(TRAVIS and not os.path.exists(SCRIPTS_DIR),
+                 "can't locate scripts directory")
+class TestScripts(unittest.TestCase):
+    """Tests for scripts in the "scripts" directory."""
+
+    @staticmethod
+    def assert_stdout(exe, *args, **kwargs):
+        exe = '%s' % os.path.join(SCRIPTS_DIR, exe)
+        cmd = [PYTHON_EXE, exe]
+        for arg in args:
+            cmd.append(arg)
+        try:
+            out = sh(cmd, **kwargs).strip()
+        except RuntimeError as err:
+            if 'AccessDenied' in str(err):
+                return str(err)
+            else:
+                raise
+        assert out, out
+        return out
+
+    @staticmethod
+    def assert_syntax(exe, args=None):
+        exe = os.path.join(SCRIPTS_DIR, exe)
+        if PY3:
+            f = open(exe, 'rt', encoding='utf8')
+        else:
+            f = open(exe, 'rt')
+        with f:
+            src = f.read()
+        ast.parse(src)
+
+    def test_coverage(self):
+        # make sure all example scripts have a test method defined
+        meths = dir(self)
+        for name in os.listdir(SCRIPTS_DIR):
+            if name.endswith('.py'):
+                if 'test_' + os.path.splitext(name)[0] not in meths:
+                    # self.assert_stdout(name)
+                    self.fail('no test defined for %r script'
+                              % os.path.join(SCRIPTS_DIR, name))
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    def test_executable(self):
+        for name in os.listdir(SCRIPTS_DIR):
+            if name.endswith('.py'):
+                path = os.path.join(SCRIPTS_DIR, name)
+                if not stat.S_IXUSR & os.stat(path)[stat.ST_MODE]:
+                    self.fail('%r is not executable' % path)
+
+    def test_disk_usage(self):
+        self.assert_stdout('disk_usage.py')
+
+    def test_free(self):
+        self.assert_stdout('free.py')
+
+    def test_meminfo(self):
+        self.assert_stdout('meminfo.py')
+
+    def test_procinfo(self):
+        self.assert_stdout('procinfo.py', str(os.getpid()))
+
+    # can't find users on APPVEYOR or TRAVIS
+    @unittest.skipIf(APPVEYOR or TRAVIS and not psutil.users(),
+                     "unreliable on APPVEYOR or TRAVIS")
+    def test_who(self):
+        self.assert_stdout('who.py')
+
+    def test_ps(self):
+        self.assert_stdout('ps.py')
+
+    def test_pstree(self):
+        self.assert_stdout('pstree.py')
+
+    def test_netstat(self):
+        self.assert_stdout('netstat.py')
+
+    # permission denied on travis
+    @unittest.skipIf(TRAVIS, "unreliable on TRAVIS")
+    def test_ifconfig(self):
+        self.assert_stdout('ifconfig.py')
+
+    @unittest.skipIf(not HAS_MEMORY_MAPS, "not supported")
+    def test_pmap(self):
+        self.assert_stdout('pmap.py', str(os.getpid()))
+
+    @unittest.skipIf(not HAS_MEMORY_FULL_INFO, "not supported")
+    def test_procsmem(self):
+        self.assert_stdout('procsmem.py', stderr=DEVNULL)
+
+    def test_killall(self):
+        self.assert_syntax('killall.py')
+
+    def test_nettop(self):
+        self.assert_syntax('nettop.py')
+
+    def test_top(self):
+        self.assert_syntax('top.py')
+
+    def test_iotop(self):
+        self.assert_syntax('iotop.py')
+
+    def test_pidof(self):
+        output = self.assert_stdout('pidof.py', psutil.Process().name())
+        self.assertIn(str(os.getpid()), output)
+
+    @unittest.skipIf(not WINDOWS, "WINDOWS only")
+    def test_winservices(self):
+        self.assert_stdout('winservices.py')
+
+    def test_cpu_distribution(self):
+        self.assert_syntax('cpu_distribution.py')
+
+    @unittest.skipIf(not HAS_SENSORS_TEMPERATURES, "not supported")
+    @unittest.skipIf(TRAVIS, "unreliable on TRAVIS")
+    def test_temperatures(self):
+        self.assert_stdout('temperatures.py')
+
+    @unittest.skipIf(not HAS_SENSORS_FANS, "not supported")
+    @unittest.skipIf(TRAVIS, "unreliable on TRAVIS")
+    def test_fans(self):
+        self.assert_stdout('fans.py')
+
+    @unittest.skipIf(not HAS_SENSORS_BATTERY, "not supported")
+    @unittest.skipIf(not HAS_BATTERY, "no battery")
+    def test_battery(self):
+        self.assert_stdout('battery.py')
+
+    def test_sensors(self):
+        self.assert_stdout('sensors.py')
+
+
+# ===================================================================
+# --- Unit tests for test utilities.
+# ===================================================================
+
+
+class TestRetryDecorator(unittest.TestCase):
+
+    @mock.patch('time.sleep')
+    def test_retry_success(self, sleep):
+        # Fail 3 times out of 5; make sure the decorated fun returns.
+
+        @retry(retries=5, interval=1, logfun=None)
+        def foo():
+            while queue:
+                queue.pop()
+                1 / 0
+            return 1
+
+        queue = list(range(3))
+        self.assertEqual(foo(), 1)
+        self.assertEqual(sleep.call_count, 3)
+
+    @mock.patch('time.sleep')
+    def test_retry_failure(self, sleep):
+        # Fail 6 times out of 5; th function is supposed to raise exc.
+
+        @retry(retries=5, interval=1, logfun=None)
+        def foo():
+            while queue:
+                queue.pop()
+                1 / 0
+            return 1
+
+        queue = list(range(6))
+        self.assertRaises(ZeroDivisionError, foo)
+        self.assertEqual(sleep.call_count, 5)
+
+    @mock.patch('time.sleep')
+    def test_exception_arg(self, sleep):
+        @retry(exception=ValueError, interval=1)
+        def foo():
+            raise TypeError
+
+        self.assertRaises(TypeError, foo)
+        self.assertEqual(sleep.call_count, 0)
+
+    @mock.patch('time.sleep')
+    def test_no_interval_arg(self, sleep):
+        # if interval is not specified sleep is not supposed to be called
+
+        @retry(retries=5, interval=None, logfun=None)
+        def foo():
+            1 / 0
+
+        self.assertRaises(ZeroDivisionError, foo)
+        self.assertEqual(sleep.call_count, 0)
+
+    @mock.patch('time.sleep')
+    def test_retries_arg(self, sleep):
+
+        @retry(retries=5, interval=1, logfun=None)
+        def foo():
+            1 / 0
+
+        self.assertRaises(ZeroDivisionError, foo)
+        self.assertEqual(sleep.call_count, 5)
+
+    @mock.patch('time.sleep')
+    def test_retries_and_timeout_args(self, sleep):
+        self.assertRaises(ValueError, retry, retries=5, timeout=1)
+
+
+class TestSyncTestUtils(unittest.TestCase):
+
+    def tearDown(self):
+        safe_rmpath(TESTFN)
+
+    def test_wait_for_pid(self):
+        wait_for_pid(os.getpid())
+        nopid = max(psutil.pids()) + 99999
+        with mock.patch('psutil.tests.retry.__iter__', return_value=iter([0])):
+            self.assertRaises(psutil.NoSuchProcess, wait_for_pid, nopid)
+
+    def test_wait_for_file(self):
+        with open(TESTFN, 'w') as f:
+            f.write('foo')
+        wait_for_file(TESTFN)
+        assert not os.path.exists(TESTFN)
+
+    def test_wait_for_file_empty(self):
+        with open(TESTFN, 'w'):
+            pass
+        wait_for_file(TESTFN, empty=True)
+        assert not os.path.exists(TESTFN)
+
+    def test_wait_for_file_no_file(self):
+        with mock.patch('psutil.tests.retry.__iter__', return_value=iter([0])):
+            self.assertRaises(IOError, wait_for_file, TESTFN)
+
+    def test_wait_for_file_no_delete(self):
+        with open(TESTFN, 'w') as f:
+            f.write('foo')
+        wait_for_file(TESTFN, delete=False)
+        assert os.path.exists(TESTFN)
+
+    def test_call_until(self):
+        ret = call_until(lambda: 1, "ret == 1")
+        self.assertEqual(ret, 1)
+
+
+class TestFSTestUtils(unittest.TestCase):
+
+    def setUp(self):
+        safe_rmpath(TESTFN)
+
+    tearDown = setUp
+
+    def test_safe_mkdir(self):
+        safe_mkdir(TESTFN)
+        assert os.path.isdir(TESTFN)
+        safe_mkdir(TESTFN)
+        assert os.path.isdir(TESTFN)
+
+    def test_safe_rmpath(self):
+        # test file is removed
+        open(TESTFN, 'w').close()
+        safe_rmpath(TESTFN)
+        assert not os.path.exists(TESTFN)
+        # test no exception if path does not exist
+        safe_rmpath(TESTFN)
+        # test dir is removed
+        os.mkdir(TESTFN)
+        safe_rmpath(TESTFN)
+        assert not os.path.exists(TESTFN)
+        # test other exceptions are raised
+        with mock.patch('psutil.tests.os.stat',
+                        side_effect=OSError(errno.EINVAL, "")) as m:
+            with self.assertRaises(OSError):
+                safe_rmpath(TESTFN)
+            assert m.called
+
+    def test_chdir(self):
+        base = os.getcwd()
+        os.mkdir(TESTFN)
+        with chdir(TESTFN):
+            self.assertEqual(os.getcwd(), os.path.join(base, TESTFN))
+        self.assertEqual(os.getcwd(), base)
+
+
+class TestProcessUtils(unittest.TestCase):
+
+    def test_reap_children(self):
+        subp = get_test_subprocess()
+        p = psutil.Process(subp.pid)
+        assert p.is_running()
+        reap_children()
+        assert not p.is_running()
+        assert not psutil.tests._pids_started
+        assert not psutil.tests._subprocesses_started
+
+    def test_create_proc_children_pair(self):
+        p1, p2 = create_proc_children_pair()
+        self.assertNotEqual(p1.pid, p2.pid)
+        assert p1.is_running()
+        assert p2.is_running()
+        children = psutil.Process().children(recursive=True)
+        self.assertEqual(len(children), 2)
+        self.assertIn(p1, children)
+        self.assertIn(p2, children)
+        self.assertEqual(p1.ppid(), os.getpid())
+        self.assertEqual(p2.ppid(), p1.pid)
+
+        # make sure both of them are cleaned up
+        reap_children()
+        assert not p1.is_running()
+        assert not p2.is_running()
+        assert not psutil.tests._pids_started
+        assert not psutil.tests._subprocesses_started
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    def test_create_zombie_proc(self):
+        zpid = create_zombie_proc()
+        self.addCleanup(reap_children, recursive=True)
+        p = psutil.Process(zpid)
+        self.assertEqual(p.status(), psutil.STATUS_ZOMBIE)
+
+
+class TestNetUtils(unittest.TestCase):
+
+    def bind_socket(self):
+        port = get_free_port()
+        with contextlib.closing(bind_socket(addr=('', port))) as s:
+            self.assertEqual(s.getsockname()[1], port)
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    def test_bind_unix_socket(self):
+        with unix_socket_path() as name:
+            sock = bind_unix_socket(name)
+            with contextlib.closing(sock):
+                self.assertEqual(sock.family, socket.AF_UNIX)
+                self.assertEqual(sock.type, socket.SOCK_STREAM)
+                self.assertEqual(sock.getsockname(), name)
+                assert os.path.exists(name)
+                assert stat.S_ISSOCK(os.stat(name).st_mode)
+        # UDP
+        with unix_socket_path() as name:
+            sock = bind_unix_socket(name, type=socket.SOCK_DGRAM)
+            with contextlib.closing(sock):
+                self.assertEqual(sock.type, socket.SOCK_DGRAM)
+
+    def tcp_tcp_socketpair(self):
+        addr = ("127.0.0.1", get_free_port())
+        server, client = tcp_socketpair(socket.AF_INET, addr=addr)
+        with contextlib.closing(server):
+            with contextlib.closing(client):
+                # Ensure they are connected and the positions are
+                # correct.
+                self.assertEqual(server.getsockname(), addr)
+                self.assertEqual(client.getpeername(), addr)
+                self.assertNotEqual(client.getsockname(), addr)
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    def test_unix_socketpair(self):
+        p = psutil.Process()
+        num_fds = p.num_fds()
+        assert not p.connections(kind='unix')
+        with unix_socket_path() as name:
+            server, client = unix_socketpair(name)
+            try:
+                assert os.path.exists(name)
+                assert stat.S_ISSOCK(os.stat(name).st_mode)
+                self.assertEqual(p.num_fds() - num_fds, 2)
+                self.assertEqual(len(p.connections(kind='unix')), 2)
+                self.assertEqual(server.getsockname(), name)
+                self.assertEqual(client.getpeername(), name)
+            finally:
+                client.close()
+                server.close()
+
+    def test_create_sockets(self):
+        with create_sockets() as socks:
+            fams = collections.defaultdict(int)
+            types = collections.defaultdict(int)
+            for s in socks:
+                fams[s.family] += 1
+                # work around http://bugs.python.org/issue30204
+                types[s.getsockopt(socket.SOL_SOCKET, socket.SO_TYPE)] += 1
+            self.assertGreaterEqual(fams[socket.AF_INET], 2)
+            if supports_ipv6():
+                self.assertGreaterEqual(fams[socket.AF_INET6], 2)
+            if POSIX and HAS_CONNECTIONS_UNIX:
+                self.assertGreaterEqual(fams[socket.AF_UNIX], 2)
+            self.assertGreaterEqual(types[socket.SOCK_STREAM], 2)
+            self.assertGreaterEqual(types[socket.SOCK_DGRAM], 2)
+
+
+class TestOtherUtils(unittest.TestCase):
+
+    def test_is_namedtuple(self):
+        assert is_namedtuple(collections.namedtuple('foo', 'a b c')(1, 2, 3))
+        assert not is_namedtuple(tuple())
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_osx.py b/psutil/tests/test_osx.py
new file mode 100755
index 00000000..bcb2ba4e
--- /dev/null
+++ b/psutil/tests/test_osx.py
@@ -0,0 +1,303 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""OSX specific tests."""
+
+import os
+import re
+import time
+
+import psutil
+from psutil import OSX
+from psutil.tests import create_zombie_proc
+from psutil.tests import get_test_subprocess
+from psutil.tests import HAS_BATTERY
+from psutil.tests import MEMORY_TOLERANCE
+from psutil.tests import reap_children
+from psutil.tests import retry_before_failing
+from psutil.tests import run_test_module_by_name
+from psutil.tests import sh
+from psutil.tests import unittest
+
+
+PAGESIZE = os.sysconf("SC_PAGE_SIZE") if OSX else None
+
+
+def sysctl(cmdline):
+    """Expects a sysctl command with an argument and parse the result
+    returning only the value of interest.
+    """
+    out = sh(cmdline)
+    result = out.split()[1]
+    try:
+        return int(result)
+    except ValueError:
+        return result
+
+
+def vm_stat(field):
+    """Wrapper around 'vm_stat' cmdline utility."""
+    out = sh('vm_stat')
+    for line in out.split('\n'):
+        if field in line:
+            break
+    else:
+        raise ValueError("line not found")
+    return int(re.search(r'\d+', line).group(0)) * PAGESIZE
+
+
+# http://code.activestate.com/recipes/578019/
+def human2bytes(s):
+    SYMBOLS = {
+        'customary': ('B', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'),
+    }
+    init = s
+    num = ""
+    while s and s[0:1].isdigit() or s[0:1] == '.':
+        num += s[0]
+        s = s[1:]
+    num = float(num)
+    letter = s.strip()
+    for name, sset in SYMBOLS.items():
+        if letter in sset:
+            break
+    else:
+        if letter == 'k':
+            sset = SYMBOLS['customary']
+            letter = letter.upper()
+        else:
+            raise ValueError("can't interpret %r" % init)
+    prefix = {sset[0]: 1}
+    for i, s in enumerate(sset[1:]):
+        prefix[s] = 1 << (i + 1) * 10
+    return int(num * prefix[letter])
+
+
+@unittest.skipIf(not OSX, "OSX only")
+class TestProcess(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        cls.pid = get_test_subprocess().pid
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children()
+
+    def test_process_create_time(self):
+        output = sh("ps -o lstart -p %s" % self.pid)
+        start_ps = output.replace('STARTED', '').strip()
+        hhmmss = start_ps.split(' ')[-2]
+        year = start_ps.split(' ')[-1]
+        start_psutil = psutil.Process(self.pid).create_time()
+        self.assertEqual(
+            hhmmss,
+            time.strftime("%H:%M:%S", time.localtime(start_psutil)))
+        self.assertEqual(
+            year,
+            time.strftime("%Y", time.localtime(start_psutil)))
+
+
+@unittest.skipIf(not OSX, "OSX only")
+class TestZombieProcessAPIs(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        zpid = create_zombie_proc()
+        cls.p = psutil.Process(zpid)
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children(recursive=True)
+
+    def test_pidtask_info(self):
+        self.assertEqual(self.p.status(), psutil.STATUS_ZOMBIE)
+        self.p.ppid()
+        self.p.uids()
+        self.p.gids()
+        self.p.terminal()
+        self.p.create_time()
+
+    def test_exe(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.exe)
+
+    def test_cmdline(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.cmdline)
+
+    def test_environ(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.environ)
+
+    def test_cwd(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.cwd)
+
+    def test_memory_full_info(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.memory_full_info)
+
+    def test_cpu_times(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.cpu_times)
+
+    def test_num_ctx_switches(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.num_ctx_switches)
+
+    def test_num_threads(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.num_threads)
+
+    def test_open_files(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.open_files)
+
+    def test_connections(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.connections)
+
+    def test_num_fds(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.num_fds)
+
+    def test_threads(self):
+        self.assertRaises((psutil.ZombieProcess, psutil.AccessDenied),
+                          self.p.threads)
+
+    def test_memory_maps(self):
+        self.assertRaises(psutil.ZombieProcess, self.p.memory_maps)
+
+
+@unittest.skipIf(not OSX, "OSX only")
+class TestSystemAPIs(unittest.TestCase):
+
+    # --- disk
+
+    def test_disks(self):
+        # test psutil.disk_usage() and psutil.disk_partitions()
+        # against "df -a"
+        def df(path):
+            out = sh('df -k "%s"' % path).strip()
+            lines = out.split('\n')
+            lines.pop(0)
+            line = lines.pop(0)
+            dev, total, used, free = line.split()[:4]
+            if dev == 'none':
+                dev = ''
+            total = int(total) * 1024
+            used = int(used) * 1024
+            free = int(free) * 1024
+            return dev, total, used, free
+
+        for part in psutil.disk_partitions(all=False):
+            usage = psutil.disk_usage(part.mountpoint)
+            dev, total, used, free = df(part.mountpoint)
+            self.assertEqual(part.device, dev)
+            self.assertEqual(usage.total, total)
+            # 10 MB tollerance
+            if abs(usage.free - free) > 10 * 1024 * 1024:
+                self.fail("psutil=%s, df=%s" % usage.free, free)
+            if abs(usage.used - used) > 10 * 1024 * 1024:
+                self.fail("psutil=%s, df=%s" % usage.used, used)
+
+    # --- cpu
+
+    def test_cpu_count_logical(self):
+        num = sysctl("sysctl hw.logicalcpu")
+        self.assertEqual(num, psutil.cpu_count(logical=True))
+
+    def test_cpu_count_physical(self):
+        num = sysctl("sysctl hw.physicalcpu")
+        self.assertEqual(num, psutil.cpu_count(logical=False))
+
+    def test_cpu_freq(self):
+        freq = psutil.cpu_freq()
+        self.assertEqual(
+            freq.current * 1000 * 1000, sysctl("sysctl hw.cpufrequency"))
+        self.assertEqual(
+            freq.min * 1000 * 1000, sysctl("sysctl hw.cpufrequency_min"))
+        self.assertEqual(
+            freq.max * 1000 * 1000, sysctl("sysctl hw.cpufrequency_max"))
+
+    # --- virtual mem
+
+    def test_vmem_total(self):
+        sysctl_hwphymem = sysctl('sysctl hw.memsize')
+        self.assertEqual(sysctl_hwphymem, psutil.virtual_memory().total)
+
+    @retry_before_failing()
+    def test_vmem_free(self):
+        vmstat_val = vm_stat("free")
+        psutil_val = psutil.virtual_memory().free
+        self.assertAlmostEqual(psutil_val, vmstat_val, delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_vmem_available(self):
+        vmstat_val = vm_stat("inactive") + vm_stat("free")
+        psutil_val = psutil.virtual_memory().available
+        self.assertAlmostEqual(psutil_val, vmstat_val, delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_vmem_active(self):
+        vmstat_val = vm_stat("active")
+        psutil_val = psutil.virtual_memory().active
+        self.assertAlmostEqual(psutil_val, vmstat_val, delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_vmem_inactive(self):
+        vmstat_val = vm_stat("inactive")
+        psutil_val = psutil.virtual_memory().inactive
+        self.assertAlmostEqual(psutil_val, vmstat_val, delta=MEMORY_TOLERANCE)
+
+    @retry_before_failing()
+    def test_vmem_wired(self):
+        vmstat_val = vm_stat("wired")
+        psutil_val = psutil.virtual_memory().wired
+        self.assertAlmostEqual(psutil_val, vmstat_val, delta=MEMORY_TOLERANCE)
+
+    # --- swap mem
+
+    @retry_before_failing()
+    def test_swapmem_sin(self):
+        vmstat_val = vm_stat("Pageins")
+        psutil_val = psutil.swap_memory().sin
+        self.assertEqual(psutil_val, vmstat_val)
+
+    @retry_before_failing()
+    def test_swapmem_sout(self):
+        vmstat_val = vm_stat("Pageout")
+        psutil_val = psutil.swap_memory().sout
+        self.assertEqual(psutil_val, vmstat_val)
+
+    # Not very reliable.
+    # def test_swapmem_total(self):
+    #     out = sh('sysctl vm.swapusage')
+    #     out = out.replace('vm.swapusage: ', '')
+    #     total, used, free = re.findall('\d+.\d+\w', out)
+    #     psutil_smem = psutil.swap_memory()
+    #     self.assertEqual(psutil_smem.total, human2bytes(total))
+    #     self.assertEqual(psutil_smem.used, human2bytes(used))
+    #     self.assertEqual(psutil_smem.free, human2bytes(free))
+
+    # --- network
+
+    def test_net_if_stats(self):
+        for name, stats in psutil.net_if_stats().items():
+            try:
+                out = sh("ifconfig %s" % name)
+            except RuntimeError:
+                pass
+            else:
+                self.assertEqual(stats.isup, 'RUNNING' in out, msg=out)
+                self.assertEqual(stats.mtu,
+                                 int(re.findall(r'mtu (\d+)', out)[0]))
+
+    # --- sensors_battery
+
+    @unittest.skipIf(not HAS_BATTERY, "no battery")
+    def test_sensors_battery(self):
+        out = sh("pmset -g batt")
+        percent = re.search("(\d+)%", out).group(1)
+        drawing_from = re.search("Now drawing from '([^']+)'", out).group(1)
+        power_plugged = drawing_from == "AC Power"
+        psutil_result = psutil.sensors_battery()
+        self.assertEqual(psutil_result.power_plugged, power_plugged)
+        self.assertEqual(psutil_result.percent, int(percent))
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_posix.py b/psutil/tests/test_posix.py
new file mode 100755
index 00000000..e9a6f5f6
--- /dev/null
+++ b/psutil/tests/test_posix.py
@@ -0,0 +1,418 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""POSIX specific tests."""
+
+import datetime
+import errno
+import os
+import re
+import subprocess
+import sys
+import time
+
+import psutil
+from psutil import AIX
+from psutil import BSD
+from psutil import LINUX
+from psutil import OPENBSD
+from psutil import OSX
+from psutil import POSIX
+from psutil import SUNOS
+from psutil._compat import PY3
+from psutil.tests import APPVEYOR
+from psutil.tests import get_kernel_version
+from psutil.tests import get_test_subprocess
+from psutil.tests import mock
+from psutil.tests import PYTHON_EXE
+from psutil.tests import reap_children
+from psutil.tests import retry_before_failing
+from psutil.tests import run_test_module_by_name
+from psutil.tests import sh
+from psutil.tests import skip_on_access_denied
+from psutil.tests import TRAVIS
+from psutil.tests import unittest
+from psutil.tests import wait_for_pid
+from psutil.tests import which
+
+
+def ps(cmd):
+    """Expects a ps command with a -o argument and parse the result
+    returning only the value of interest.
+    """
+    if not LINUX:
+        cmd = cmd.replace(" --no-headers ", " ")
+    if SUNOS:
+        cmd = cmd.replace("-o start", "-o stime")
+    if AIX:
+        cmd = cmd.replace("-o rss", "-o rssize")
+    output = sh(cmd)
+    if not LINUX:
+        output = output.split('\n')[1].strip()
+    try:
+        return int(output)
+    except ValueError:
+        return output
+
+# ps "-o" field names differ wildly between platforms.
+# "comm" means "only executable name" but is not available on BSD platforms.
+# "args" means "command with all its arguments", and is also not available
+# on BSD platforms.
+# "command" is like "args" on most platforms, but like "comm" on AIX,
+# and not available on SUNOS.
+# so for the executable name we can use "comm" on Solaris and split "command"
+# on other platforms.
+# to get the cmdline (with args) we have to use "args" on AIX and
+# Solaris, and can use "command" on all others.
+
+
+def ps_name(pid):
+    field = "command"
+    if SUNOS:
+        field = "comm"
+    return ps("ps --no-headers -o %s -p %s" % (field, pid)).split(' ')[0]
+
+
+def ps_args(pid):
+    field = "command"
+    if AIX or SUNOS:
+        field = "args"
+    return ps("ps --no-headers -o %s -p %s" % (field, pid))
+
+
+@unittest.skipIf(not POSIX, "POSIX only")
+class TestProcess(unittest.TestCase):
+    """Compare psutil results against 'ps' command line utility (mainly)."""
+
+    @classmethod
+    def setUpClass(cls):
+        cls.pid = get_test_subprocess([PYTHON_EXE, "-E", "-O"],
+                                      stdin=subprocess.PIPE).pid
+        wait_for_pid(cls.pid)
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children()
+
+    def test_ppid(self):
+        ppid_ps = ps("ps --no-headers -o ppid -p %s" % self.pid)
+        ppid_psutil = psutil.Process(self.pid).ppid()
+        self.assertEqual(ppid_ps, ppid_psutil)
+
+    def test_uid(self):
+        uid_ps = ps("ps --no-headers -o uid -p %s" % self.pid)
+        uid_psutil = psutil.Process(self.pid).uids().real
+        self.assertEqual(uid_ps, uid_psutil)
+
+    def test_gid(self):
+        gid_ps = ps("ps --no-headers -o rgid -p %s" % self.pid)
+        gid_psutil = psutil.Process(self.pid).gids().real
+        self.assertEqual(gid_ps, gid_psutil)
+
+    def test_username(self):
+        username_ps = ps("ps --no-headers -o user -p %s" % self.pid)
+        username_psutil = psutil.Process(self.pid).username()
+        self.assertEqual(username_ps, username_psutil)
+
+    def test_username_no_resolution(self):
+        # Emulate a case where the system can't resolve the uid to
+        # a username in which case psutil is supposed to return
+        # the stringified uid.
+        p = psutil.Process()
+        with mock.patch("psutil.pwd.getpwuid", side_effect=KeyError) as fun:
+            self.assertEqual(p.username(), str(p.uids().real))
+            assert fun.called
+
+    @skip_on_access_denied()
+    @retry_before_failing()
+    def test_rss_memory(self):
+        # give python interpreter some time to properly initialize
+        # so that the results are the same
+        time.sleep(0.1)
+        rss_ps = ps("ps --no-headers -o rss -p %s" % self.pid)
+        rss_psutil = psutil.Process(self.pid).memory_info()[0] / 1024
+        self.assertEqual(rss_ps, rss_psutil)
+
+    @skip_on_access_denied()
+    @retry_before_failing()
+    def test_vsz_memory(self):
+        # give python interpreter some time to properly initialize
+        # so that the results are the same
+        time.sleep(0.1)
+        vsz_ps = ps("ps --no-headers -o vsz -p %s" % self.pid)
+        vsz_psutil = psutil.Process(self.pid).memory_info()[1] / 1024
+        self.assertEqual(vsz_ps, vsz_psutil)
+
+    def test_name(self):
+        name_ps = ps_name(self.pid)
+        # remove path if there is any, from the command
+        name_ps = os.path.basename(name_ps).lower()
+        name_psutil = psutil.Process(self.pid).name().lower()
+        # ...because of how we calculate PYTHON_EXE; on OSX this may
+        # be "pythonX.Y".
+        name_ps = re.sub(r"\d.\d", "", name_ps)
+        name_psutil = re.sub(r"\d.\d", "", name_psutil)
+        self.assertEqual(name_ps, name_psutil)
+
+    def test_name_long(self):
+        # On UNIX the kernel truncates the name to the first 15
+        # characters. In such a case psutil tries to determine the
+        # full name from the cmdline.
+        name = "long-program-name"
+        cmdline = ["long-program-name-extended", "foo", "bar"]
+        with mock.patch("psutil._psplatform.Process.name",
+                        return_value=name):
+            with mock.patch("psutil._psplatform.Process.cmdline",
+                            return_value=cmdline):
+                p = psutil.Process()
+                self.assertEqual(p.name(), "long-program-name-extended")
+
+    def test_name_long_cmdline_ad_exc(self):
+        # Same as above but emulates a case where cmdline() raises
+        # AccessDenied in which case psutil is supposed to return
+        # the truncated name instead of crashing.
+        name = "long-program-name"
+        with mock.patch("psutil._psplatform.Process.name",
+                        return_value=name):
+            with mock.patch("psutil._psplatform.Process.cmdline",
+                            side_effect=psutil.AccessDenied(0, "")):
+                p = psutil.Process()
+                self.assertEqual(p.name(), "long-program-name")
+
+    def test_name_long_cmdline_nsp_exc(self):
+        # Same as above but emulates a case where cmdline() raises NSP
+        # which is supposed to propagate.
+        name = "long-program-name"
+        with mock.patch("psutil._psplatform.Process.name",
+                        return_value=name):
+            with mock.patch("psutil._psplatform.Process.cmdline",
+                            side_effect=psutil.NoSuchProcess(0, "")):
+                p = psutil.Process()
+                self.assertRaises(psutil.NoSuchProcess, p.name)
+
+    @unittest.skipIf(OSX or BSD, 'ps -o start not available')
+    def test_create_time(self):
+        time_ps = ps("ps --no-headers -o start -p %s" % self.pid).split(' ')[0]
+        time_psutil = psutil.Process(self.pid).create_time()
+        time_psutil_tstamp = datetime.datetime.fromtimestamp(
+            time_psutil).strftime("%H:%M:%S")
+        # sometimes ps shows the time rounded up instead of down, so we check
+        # for both possible values
+        round_time_psutil = round(time_psutil)
+        round_time_psutil_tstamp = datetime.datetime.fromtimestamp(
+            round_time_psutil).strftime("%H:%M:%S")
+        self.assertIn(time_ps, [time_psutil_tstamp, round_time_psutil_tstamp])
+
+    def test_exe(self):
+        ps_pathname = ps_name(self.pid)
+        psutil_pathname = psutil.Process(self.pid).exe()
+        try:
+            self.assertEqual(ps_pathname, psutil_pathname)
+        except AssertionError:
+            # certain platforms such as BSD are more accurate returning:
+            # "/usr/local/bin/python2.7"
+            # ...instead of:
+            # "/usr/local/bin/python"
+            # We do not want to consider this difference in accuracy
+            # an error.
+            adjusted_ps_pathname = ps_pathname[:len(ps_pathname)]
+            self.assertEqual(ps_pathname, adjusted_ps_pathname)
+
+    def test_cmdline(self):
+        ps_cmdline = ps_args(self.pid)
+        psutil_cmdline = " ".join(psutil.Process(self.pid).cmdline())
+        self.assertEqual(ps_cmdline, psutil_cmdline)
+
+    # On SUNOS "ps" reads niceness /proc/pid/psinfo which returns an
+    # incorrect value (20); the real deal is getpriority(2) which
+    # returns 0; psutil relies on it, see:
+    # https://github.com/giampaolo/psutil/issues/1082
+    # AIX has the same issue
+    @unittest.skipIf(SUNOS, "not reliable on SUNOS")
+    @unittest.skipIf(AIX, "not reliable on AIX")
+    def test_nice(self):
+        ps_nice = ps("ps --no-headers -o nice -p %s" % self.pid)
+        psutil_nice = psutil.Process().nice()
+        self.assertEqual(ps_nice, psutil_nice)
+
+    def test_num_fds(self):
+        # Note: this fails from time to time; I'm keen on thinking
+        # it doesn't mean something is broken
+        def call(p, attr):
+            args = ()
+            attr = getattr(p, name, None)
+            if attr is not None and callable(attr):
+                if name == 'rlimit':
+                    args = (psutil.RLIMIT_NOFILE,)
+                attr(*args)
+            else:
+                attr
+
+        p = psutil.Process(os.getpid())
+        failures = []
+        ignored_names = ['terminate', 'kill', 'suspend', 'resume', 'nice',
+                         'send_signal', 'wait', 'children', 'as_dict',
+                         'memory_info_ex']
+        if LINUX and get_kernel_version() < (2, 6, 36):
+            ignored_names.append('rlimit')
+        if LINUX and get_kernel_version() < (2, 6, 23):
+            ignored_names.append('num_ctx_switches')
+        for name in dir(psutil.Process):
+            if (name.startswith('_') or name in ignored_names):
+                continue
+            else:
+                try:
+                    num1 = p.num_fds()
+                    for x in range(2):
+                        call(p, name)
+                    num2 = p.num_fds()
+                except psutil.AccessDenied:
+                    pass
+                else:
+                    if abs(num2 - num1) > 1:
+                        fail = "failure while processing Process.%s method " \
+                               "(before=%s, after=%s)" % (name, num1, num2)
+                        failures.append(fail)
+        if failures:
+            self.fail('\n' + '\n'.join(failures))
+
+
+@unittest.skipIf(not POSIX, "POSIX only")
+class TestSystemAPIs(unittest.TestCase):
+    """Test some system APIs."""
+
+    @retry_before_failing()
+    def test_pids(self):
+        # Note: this test might fail if the OS is starting/killing
+        # other processes in the meantime
+        if SUNOS or AIX:
+            cmd = ["ps", "-A", "-o", "pid"]
+        else:
+            cmd = ["ps", "ax", "-o", "pid"]
+        p = get_test_subprocess(cmd, stdout=subprocess.PIPE)
+        output = p.communicate()[0].strip()
+        assert p.poll() == 0
+        if PY3:
+            output = str(output, sys.stdout.encoding)
+        pids_ps = []
+        for line in output.split('\n')[1:]:
+            if line:
+                pid = int(line.split()[0].strip())
+                pids_ps.append(pid)
+        # remove ps subprocess pid which is supposed to be dead in meantime
+        pids_ps.remove(p.pid)
+        pids_psutil = psutil.pids()
+        pids_ps.sort()
+        pids_psutil.sort()
+
+        # on OSX and OPENBSD ps doesn't show pid 0
+        if OSX or OPENBSD and 0 not in pids_ps:
+            pids_ps.insert(0, 0)
+        self.assertEqual(pids_ps, pids_psutil)
+
+    # for some reason ifconfig -a does not report all interfaces
+    # returned by psutil
+    @unittest.skipIf(SUNOS, "unreliable on SUNOS")
+    @unittest.skipIf(TRAVIS, "unreliable on TRAVIS")
+    @unittest.skipIf(not which('ifconfig'), "no ifconfig cmd")
+    def test_nic_names(self):
+        output = sh("ifconfig -a")
+        for nic in psutil.net_io_counters(pernic=True).keys():
+            for line in output.split():
+                if line.startswith(nic):
+                    break
+            else:
+                self.fail(
+                    "couldn't find %s nic in 'ifconfig -a' output\n%s" % (
+                        nic, output))
+
+    # can't find users on APPVEYOR or TRAVIS
+    @unittest.skipIf(APPVEYOR or TRAVIS and not psutil.users(),
+                     "unreliable on APPVEYOR or TRAVIS")
+    @retry_before_failing()
+    def test_users(self):
+        out = sh("who")
+        lines = out.split('\n')
+        users = [x.split()[0] for x in lines]
+        terminals = [x.split()[1] for x in lines]
+        self.assertEqual(len(users), len(psutil.users()))
+        for u in psutil.users():
+            self.assertIn(u.name, users)
+            self.assertIn(u.terminal, terminals)
+
+    def test_pid_exists_let_raise(self):
+        # According to "man 2 kill" possible error values for kill
+        # are (EINVAL, EPERM, ESRCH). Test that any other errno
+        # results in an exception.
+        with mock.patch("psutil._psposix.os.kill",
+                        side_effect=OSError(errno.EBADF, "")) as m:
+            self.assertRaises(OSError, psutil._psposix.pid_exists, os.getpid())
+            assert m.called
+
+    def test_os_waitpid_let_raise(self):
+        # os.waitpid() is supposed to catch EINTR and ECHILD only.
+        # Test that any other errno results in an exception.
+        with mock.patch("psutil._psposix.os.waitpid",
+                        side_effect=OSError(errno.EBADF, "")) as m:
+            self.assertRaises(OSError, psutil._psposix.wait_pid, os.getpid())
+            assert m.called
+
+    def test_os_waitpid_eintr(self):
+        # os.waitpid() is supposed to "retry" on EINTR.
+        with mock.patch("psutil._psposix.os.waitpid",
+                        side_effect=OSError(errno.EINTR, "")) as m:
+            self.assertRaises(
+                psutil._psposix.TimeoutExpired,
+                psutil._psposix.wait_pid, os.getpid(), timeout=0.01)
+            assert m.called
+
+    def test_os_waitpid_bad_ret_status(self):
+        # Simulate os.waitpid() returning a bad status.
+        with mock.patch("psutil._psposix.os.waitpid",
+                        return_value=(1, -1)) as m:
+            self.assertRaises(ValueError,
+                              psutil._psposix.wait_pid, os.getpid())
+            assert m.called
+
+    # AIX can return '-' in df output instead of numbers, e.g. for /proc
+    @unittest.skipIf(AIX, "unreliable on AIX")
+    def test_disk_usage(self):
+        def df(device):
+            out = sh("df -k %s" % device).strip()
+            line = out.split('\n')[1]
+            fields = line.split()
+            total = int(fields[1]) * 1024
+            used = int(fields[2]) * 1024
+            free = int(fields[3]) * 1024
+            percent = float(fields[4].replace('%', ''))
+            return (total, used, free, percent)
+
+        tolerance = 4 * 1024 * 1024  # 4MB
+        for part in psutil.disk_partitions(all=False):
+            usage = psutil.disk_usage(part.mountpoint)
+            try:
+                total, used, free, percent = df(part.device)
+            except RuntimeError as err:
+                # see:
+                # https://travis-ci.org/giampaolo/psutil/jobs/138338464
+                # https://travis-ci.org/giampaolo/psutil/jobs/138343361
+                err = str(err).lower()
+                if "no such file or directory" in err or \
+                        "raw devices not supported" in err or \
+                        "permission denied" in err:
+                    continue
+                else:
+                    raise
+            else:
+                self.assertAlmostEqual(usage.total, total, delta=tolerance)
+                self.assertAlmostEqual(usage.used, used, delta=tolerance)
+                self.assertAlmostEqual(usage.free, free, delta=tolerance)
+                self.assertAlmostEqual(usage.percent, percent, delta=1)
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_process.py b/psutil/tests/test_process.py
new file mode 100755
index 00000000..33557b05
--- /dev/null
+++ b/psutil/tests/test_process.py
@@ -0,0 +1,1567 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Tests for psutil.Process class."""
+
+import collections
+import errno
+import getpass
+import itertools
+import os
+import signal
+import socket
+import subprocess
+import sys
+import tempfile
+import textwrap
+import time
+import types
+
+import psutil
+
+from psutil import AIX
+from psutil import BSD
+from psutil import LINUX
+from psutil import NETBSD
+from psutil import OPENBSD
+from psutil import OSX
+from psutil import POSIX
+from psutil import SUNOS
+from psutil import WINDOWS
+from psutil._compat import long
+from psutil._compat import PY3
+from psutil.tests import APPVEYOR
+from psutil.tests import call_until
+from psutil.tests import copyload_shared_lib
+from psutil.tests import create_exe
+from psutil.tests import create_proc_children_pair
+from psutil.tests import create_zombie_proc
+from psutil.tests import enum
+from psutil.tests import get_test_subprocess
+from psutil.tests import get_winver
+from psutil.tests import HAS_CPU_AFFINITY
+from psutil.tests import HAS_ENVIRON
+from psutil.tests import HAS_IONICE
+from psutil.tests import HAS_MEMORY_MAPS
+from psutil.tests import HAS_PROC_CPU_NUM
+from psutil.tests import HAS_PROC_IO_COUNTERS
+from psutil.tests import HAS_RLIMIT
+from psutil.tests import HAS_THREADS
+from psutil.tests import mock
+from psutil.tests import PYPY
+from psutil.tests import PYTHON_EXE
+from psutil.tests import reap_children
+from psutil.tests import retry_before_failing
+from psutil.tests import run_test_module_by_name
+from psutil.tests import safe_rmpath
+from psutil.tests import sh
+from psutil.tests import skip_on_access_denied
+from psutil.tests import skip_on_not_implemented
+from psutil.tests import TESTFILE_PREFIX
+from psutil.tests import TESTFN
+from psutil.tests import ThreadTask
+from psutil.tests import TRAVIS
+from psutil.tests import unittest
+from psutil.tests import wait_for_pid
+from psutil.tests import WIN_VISTA
+
+
+# ===================================================================
+# --- psutil.Process class tests
+# ===================================================================
+
+class TestProcess(unittest.TestCase):
+    """Tests for psutil.Process class."""
+
+    def setUp(self):
+        safe_rmpath(TESTFN)
+
+    def tearDown(self):
+        reap_children()
+
+    def test_pid(self):
+        p = psutil.Process()
+        self.assertEqual(p.pid, os.getpid())
+        sproc = get_test_subprocess()
+        self.assertEqual(psutil.Process(sproc.pid).pid, sproc.pid)
+        with self.assertRaises(AttributeError):
+            p.pid = 33
+
+    def test_kill(self):
+        sproc = get_test_subprocess()
+        test_pid = sproc.pid
+        p = psutil.Process(test_pid)
+        p.kill()
+        sig = p.wait()
+        self.assertFalse(psutil.pid_exists(test_pid))
+        if POSIX:
+            self.assertEqual(sig, -signal.SIGKILL)
+
+    def test_terminate(self):
+        sproc = get_test_subprocess()
+        test_pid = sproc.pid
+        p = psutil.Process(test_pid)
+        p.terminate()
+        sig = p.wait()
+        self.assertFalse(psutil.pid_exists(test_pid))
+        if POSIX:
+            self.assertEqual(sig, -signal.SIGTERM)
+
+    def test_send_signal(self):
+        sig = signal.SIGKILL if POSIX else signal.SIGTERM
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        p.send_signal(sig)
+        exit_sig = p.wait()
+        self.assertFalse(psutil.pid_exists(p.pid))
+        if POSIX:
+            self.assertEqual(exit_sig, -sig)
+            #
+            sproc = get_test_subprocess()
+            p = psutil.Process(sproc.pid)
+            p.send_signal(sig)
+            with mock.patch('psutil.os.kill',
+                            side_effect=OSError(errno.ESRCH, "")):
+                with self.assertRaises(psutil.NoSuchProcess):
+                    p.send_signal(sig)
+            #
+            sproc = get_test_subprocess()
+            p = psutil.Process(sproc.pid)
+            p.send_signal(sig)
+            with mock.patch('psutil.os.kill',
+                            side_effect=OSError(errno.EPERM, "")):
+                with self.assertRaises(psutil.AccessDenied):
+                    psutil.Process().send_signal(sig)
+            # Sending a signal to process with PID 0 is not allowed as
+            # it would affect every process in the process group of
+            # the calling process (os.getpid()) instead of PID 0").
+            if 0 in psutil.pids():
+                p = psutil.Process(0)
+                self.assertRaises(ValueError, p.send_signal, signal.SIGTERM)
+
+    def test_wait(self):
+        # check exit code signal
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        p.kill()
+        code = p.wait()
+        if POSIX:
+            self.assertEqual(code, -signal.SIGKILL)
+        else:
+            self.assertEqual(code, signal.SIGTERM)
+        self.assertFalse(p.is_running())
+
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        p.terminate()
+        code = p.wait()
+        if POSIX:
+            self.assertEqual(code, -signal.SIGTERM)
+        else:
+            self.assertEqual(code, signal.SIGTERM)
+        self.assertFalse(p.is_running())
+
+        # check sys.exit() code
+        code = "import time, sys; time.sleep(0.01); sys.exit(5);"
+        sproc = get_test_subprocess([PYTHON_EXE, "-c", code])
+        p = psutil.Process(sproc.pid)
+        self.assertEqual(p.wait(), 5)
+        self.assertFalse(p.is_running())
+
+        # Test wait() issued twice.
+        # It is not supposed to raise NSP when the process is gone.
+        # On UNIX this should return None, on Windows it should keep
+        # returning the exit code.
+        sproc = get_test_subprocess([PYTHON_EXE, "-c", code])
+        p = psutil.Process(sproc.pid)
+        self.assertEqual(p.wait(), 5)
+        self.assertIn(p.wait(), (5, None))
+
+        # test timeout
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        p.name()
+        self.assertRaises(psutil.TimeoutExpired, p.wait, 0.01)
+
+        # timeout < 0 not allowed
+        self.assertRaises(ValueError, p.wait, -1)
+
+    def test_wait_non_children(self):
+        # Test wait() against a process which is not our direct
+        # child.
+        p1, p2 = create_proc_children_pair()
+        self.assertRaises(psutil.TimeoutExpired, p1.wait, 0.01)
+        self.assertRaises(psutil.TimeoutExpired, p2.wait, 0.01)
+        # We also terminate the direct child otherwise the
+        # grandchild will hang until the parent is gone.
+        p1.terminate()
+        p2.terminate()
+        ret1 = p1.wait()
+        ret2 = p2.wait()
+        if POSIX:
+            self.assertEqual(ret1, -signal.SIGTERM)
+            # For processes which are not our children we're supposed
+            # to get None.
+            self.assertEqual(ret2, None)
+        else:
+            self.assertEqual(ret1, signal.SIGTERM)
+            self.assertEqual(ret1, signal.SIGTERM)
+
+    def test_wait_timeout_0(self):
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        self.assertRaises(psutil.TimeoutExpired, p.wait, 0)
+        p.kill()
+        stop_at = time.time() + 2
+        while True:
+            try:
+                code = p.wait(0)
+            except psutil.TimeoutExpired:
+                if time.time() >= stop_at:
+                    raise
+            else:
+                break
+        if POSIX:
+            self.assertEqual(code, -signal.SIGKILL)
+        else:
+            self.assertEqual(code, signal.SIGTERM)
+        self.assertFalse(p.is_running())
+
+    def test_cpu_percent(self):
+        p = psutil.Process()
+        p.cpu_percent(interval=0.001)
+        p.cpu_percent(interval=0.001)
+        for x in range(100):
+            percent = p.cpu_percent(interval=None)
+            self.assertIsInstance(percent, float)
+            self.assertGreaterEqual(percent, 0.0)
+            if not POSIX:
+                self.assertLessEqual(percent, 100.0)
+            else:
+                self.assertGreaterEqual(percent, 0.0)
+        with self.assertRaises(ValueError):
+            p.cpu_percent(interval=-1)
+
+    def test_cpu_percent_numcpus_none(self):
+        # See: https://github.com/giampaolo/psutil/issues/1087
+        with mock.patch('psutil.cpu_count', return_value=None) as m:
+            psutil.Process().cpu_percent()
+            assert m.called
+
+    def test_cpu_times(self):
+        times = psutil.Process().cpu_times()
+        assert (times.user > 0.0) or (times.system > 0.0), times
+        assert (times.children_user >= 0.0), times
+        assert (times.children_system >= 0.0), times
+        # make sure returned values can be pretty printed with strftime
+        for name in times._fields:
+            time.strftime("%H:%M:%S", time.localtime(getattr(times, name)))
+
+    def test_cpu_times_2(self):
+        user_time, kernel_time = psutil.Process().cpu_times()[:2]
+        utime, ktime = os.times()[:2]
+
+        # Use os.times()[:2] as base values to compare our results
+        # using a tolerance  of +/- 0.1 seconds.
+        # It will fail if the difference between the values is > 0.1s.
+        if (max([user_time, utime]) - min([user_time, utime])) > 0.1:
+            self.fail("expected: %s, found: %s" % (utime, user_time))
+
+        if (max([kernel_time, ktime]) - min([kernel_time, ktime])) > 0.1:
+            self.fail("expected: %s, found: %s" % (ktime, kernel_time))
+
+    @unittest.skipIf(not HAS_PROC_CPU_NUM, "not supported")
+    def test_cpu_num(self):
+        p = psutil.Process()
+        num = p.cpu_num()
+        self.assertGreaterEqual(num, 0)
+        if psutil.cpu_count() == 1:
+            self.assertEqual(num, 0)
+        self.assertIn(p.cpu_num(), range(psutil.cpu_count()))
+
+    def test_create_time(self):
+        sproc = get_test_subprocess()
+        now = time.time()
+        p = psutil.Process(sproc.pid)
+        create_time = p.create_time()
+
+        # Use time.time() as base value to compare our result using a
+        # tolerance of +/- 1 second.
+        # It will fail if the difference between the values is > 2s.
+        difference = abs(create_time - now)
+        if difference > 2:
+            self.fail("expected: %s, found: %s, difference: %s"
+                      % (now, create_time, difference))
+
+        # make sure returned value can be pretty printed with strftime
+        time.strftime("%Y %m %d %H:%M:%S", time.localtime(p.create_time()))
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    @unittest.skipIf(TRAVIS, 'not reliable on TRAVIS')
+    def test_terminal(self):
+        terminal = psutil.Process().terminal()
+        if sys.stdin.isatty() or sys.stdout.isatty():
+            tty = os.path.realpath(sh('tty'))
+            self.assertEqual(terminal, tty)
+        else:
+            self.assertIsNone(terminal)
+
+    @unittest.skipIf(not HAS_PROC_IO_COUNTERS, 'not supported')
+    @skip_on_not_implemented(only_if=LINUX)
+    def test_io_counters(self):
+        p = psutil.Process()
+
+        # test reads
+        io1 = p.io_counters()
+        with open(PYTHON_EXE, 'rb') as f:
+            f.read()
+        io2 = p.io_counters()
+        if not BSD and not AIX:
+            self.assertGreater(io2.read_count, io1.read_count)
+            self.assertEqual(io2.write_count, io1.write_count)
+            if LINUX:
+                self.assertGreater(io2.read_chars, io1.read_chars)
+                self.assertEqual(io2.write_chars, io1.write_chars)
+        else:
+            self.assertGreaterEqual(io2.read_bytes, io1.read_bytes)
+            self.assertGreaterEqual(io2.write_bytes, io1.write_bytes)
+
+        # test writes
+        io1 = p.io_counters()
+        with tempfile.TemporaryFile(prefix=TESTFILE_PREFIX) as f:
+            if PY3:
+                f.write(bytes("x" * 1000000, 'ascii'))
+            else:
+                f.write("x" * 1000000)
+        io2 = p.io_counters()
+        self.assertGreaterEqual(io2.write_count, io1.write_count)
+        self.assertGreaterEqual(io2.write_bytes, io1.write_bytes)
+        self.assertGreaterEqual(io2.read_count, io1.read_count)
+        self.assertGreaterEqual(io2.read_bytes, io1.read_bytes)
+        if LINUX:
+            self.assertGreater(io2.write_chars, io1.write_chars)
+            self.assertGreaterEqual(io2.read_chars, io1.read_chars)
+
+        # sanity check
+        for i in range(len(io2)):
+            if BSD and i >= 2:
+                # On BSD read_bytes and write_bytes are always set to -1.
+                continue
+            self.assertGreaterEqual(io2[i], 0)
+            self.assertGreaterEqual(io2[i], 0)
+
+    @unittest.skipIf(not HAS_IONICE, "not supported")
+    @unittest.skipIf(WINDOWS and get_winver() < WIN_VISTA, 'not supported')
+    def test_ionice(self):
+        if LINUX:
+            from psutil import (IOPRIO_CLASS_NONE, IOPRIO_CLASS_RT,
+                                IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE)
+            self.assertEqual(IOPRIO_CLASS_NONE, 0)
+            self.assertEqual(IOPRIO_CLASS_RT, 1)
+            self.assertEqual(IOPRIO_CLASS_BE, 2)
+            self.assertEqual(IOPRIO_CLASS_IDLE, 3)
+            p = psutil.Process()
+            try:
+                p.ionice(2)
+                ioclass, value = p.ionice()
+                if enum is not None:
+                    self.assertIsInstance(ioclass, enum.IntEnum)
+                self.assertEqual(ioclass, 2)
+                self.assertEqual(value, 4)
+                #
+                p.ionice(3)
+                ioclass, value = p.ionice()
+                self.assertEqual(ioclass, 3)
+                self.assertEqual(value, 0)
+                #
+                p.ionice(2, 0)
+                ioclass, value = p.ionice()
+                self.assertEqual(ioclass, 2)
+                self.assertEqual(value, 0)
+                p.ionice(2, 7)
+                ioclass, value = p.ionice()
+                self.assertEqual(ioclass, 2)
+                self.assertEqual(value, 7)
+            finally:
+                p.ionice(IOPRIO_CLASS_NONE)
+        else:
+            p = psutil.Process()
+            original = p.ionice()
+            self.assertIsInstance(original, int)
+            try:
+                value = 0  # very low
+                if original == value:
+                    value = 1  # low
+                p.ionice(value)
+                self.assertEqual(p.ionice(), value)
+            finally:
+                p.ionice(original)
+
+    @unittest.skipIf(not HAS_IONICE, "not supported")
+    @unittest.skipIf(WINDOWS and get_winver() < WIN_VISTA, 'not supported')
+    def test_ionice_errs(self):
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        if LINUX:
+            self.assertRaises(ValueError, p.ionice, 2, 10)
+            self.assertRaises(ValueError, p.ionice, 2, -1)
+            self.assertRaises(ValueError, p.ionice, 4)
+            self.assertRaises(TypeError, p.ionice, 2, "foo")
+            self.assertRaisesRegex(
+                ValueError, "can't specify value with IOPRIO_CLASS_NONE",
+                p.ionice, psutil.IOPRIO_CLASS_NONE, 1)
+            self.assertRaisesRegex(
+                ValueError, "can't specify value with IOPRIO_CLASS_IDLE",
+                p.ionice, psutil.IOPRIO_CLASS_IDLE, 1)
+            self.assertRaisesRegex(
+                ValueError, "'ioclass' argument must be specified",
+                p.ionice, value=1)
+        else:
+            self.assertRaises(ValueError, p.ionice, 3)
+            self.assertRaises(TypeError, p.ionice, 2, 1)
+
+    @unittest.skipIf(not HAS_RLIMIT, "not supported")
+    def test_rlimit_get(self):
+        import resource
+        p = psutil.Process(os.getpid())
+        names = [x for x in dir(psutil) if x.startswith('RLIMIT')]
+        assert names, names
+        for name in names:
+            value = getattr(psutil, name)
+            self.assertGreaterEqual(value, 0)
+            if name in dir(resource):
+                self.assertEqual(value, getattr(resource, name))
+                # XXX - On PyPy RLIMIT_INFINITY returned by
+                # resource.getrlimit() is reported as a very big long
+                # number instead of -1. It looks like a bug with PyPy.
+                if PYPY:
+                    continue
+                self.assertEqual(p.rlimit(value), resource.getrlimit(value))
+            else:
+                ret = p.rlimit(value)
+                self.assertEqual(len(ret), 2)
+                self.assertGreaterEqual(ret[0], -1)
+                self.assertGreaterEqual(ret[1], -1)
+
+    @unittest.skipIf(not HAS_RLIMIT, "not supported")
+    def test_rlimit_set(self):
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        p.rlimit(psutil.RLIMIT_NOFILE, (5, 5))
+        self.assertEqual(p.rlimit(psutil.RLIMIT_NOFILE), (5, 5))
+        # If pid is 0 prlimit() applies to the calling process and
+        # we don't want that.
+        with self.assertRaises(ValueError):
+            psutil._psplatform.Process(0).rlimit(0)
+        with self.assertRaises(ValueError):
+            p.rlimit(psutil.RLIMIT_NOFILE, (5, 5, 5))
+
+    @unittest.skipIf(not HAS_RLIMIT, "not supported")
+    def test_rlimit(self):
+        p = psutil.Process()
+        soft, hard = p.rlimit(psutil.RLIMIT_FSIZE)
+        try:
+            p.rlimit(psutil.RLIMIT_FSIZE, (1024, hard))
+            with open(TESTFN, "wb") as f:
+                f.write(b"X" * 1024)
+            # write() or flush() doesn't always cause the exception
+            # but close() will.
+            with self.assertRaises(IOError) as exc:
+                with open(TESTFN, "wb") as f:
+                    f.write(b"X" * 1025)
+            self.assertEqual(exc.exception.errno if PY3 else exc.exception[0],
+                             errno.EFBIG)
+        finally:
+            p.rlimit(psutil.RLIMIT_FSIZE, (soft, hard))
+            self.assertEqual(p.rlimit(psutil.RLIMIT_FSIZE), (soft, hard))
+
+    @unittest.skipIf(not HAS_RLIMIT, "not supported")
+    def test_rlimit_infinity(self):
+        # First set a limit, then re-set it by specifying INFINITY
+        # and assume we overridden the previous limit.
+        p = psutil.Process()
+        soft, hard = p.rlimit(psutil.RLIMIT_FSIZE)
+        try:
+            p.rlimit(psutil.RLIMIT_FSIZE, (1024, hard))
+            p.rlimit(psutil.RLIMIT_FSIZE, (psutil.RLIM_INFINITY, hard))
+            with open(TESTFN, "wb") as f:
+                f.write(b"X" * 2048)
+        finally:
+            p.rlimit(psutil.RLIMIT_FSIZE, (soft, hard))
+            self.assertEqual(p.rlimit(psutil.RLIMIT_FSIZE), (soft, hard))
+
+    @unittest.skipIf(not HAS_RLIMIT, "not supported")
+    def test_rlimit_infinity_value(self):
+        # RLIMIT_FSIZE should be RLIM_INFINITY, which will be a really
+        # big number on a platform with large file support.  On these
+        # platforms we need to test that the get/setrlimit functions
+        # properly convert the number to a C long long and that the
+        # conversion doesn't raise an error.
+        p = psutil.Process()
+        soft, hard = p.rlimit(psutil.RLIMIT_FSIZE)
+        self.assertEqual(psutil.RLIM_INFINITY, hard)
+        p.rlimit(psutil.RLIMIT_FSIZE, (soft, hard))
+
+    def test_num_threads(self):
+        # on certain platforms such as Linux we might test for exact
+        # thread number, since we always have with 1 thread per process,
+        # but this does not apply across all platforms (OSX, Windows)
+        p = psutil.Process()
+        if OPENBSD:
+            try:
+                step1 = p.num_threads()
+            except psutil.AccessDenied:
+                raise unittest.SkipTest("on OpenBSD this requires root access")
+        else:
+            step1 = p.num_threads()
+
+        with ThreadTask():
+            step2 = p.num_threads()
+            self.assertEqual(step2, step1 + 1)
+
+    @unittest.skipIf(not WINDOWS, 'WINDOWS only')
+    def test_num_handles(self):
+        # a better test is done later into test/_windows.py
+        p = psutil.Process()
+        self.assertGreater(p.num_handles(), 0)
+
+    @unittest.skipIf(not HAS_THREADS, 'not supported')
+    def test_threads(self):
+        p = psutil.Process()
+        if OPENBSD:
+            try:
+                step1 = p.threads()
+            except psutil.AccessDenied:
+                raise unittest.SkipTest("on OpenBSD this requires root access")
+        else:
+            step1 = p.threads()
+
+        with ThreadTask():
+            step2 = p.threads()
+            self.assertEqual(len(step2), len(step1) + 1)
+            # on Linux, first thread id is supposed to be this process
+            if LINUX:
+                self.assertEqual(step2[0].id, os.getpid())
+            athread = step2[0]
+            # test named tuple
+            self.assertEqual(athread.id, athread[0])
+            self.assertEqual(athread.user_time, athread[1])
+            self.assertEqual(athread.system_time, athread[2])
+
+    @retry_before_failing()
+    @skip_on_access_denied(only_if=OSX)
+    @unittest.skipIf(not HAS_THREADS, 'not supported')
+    def test_threads_2(self):
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        if OPENBSD:
+            try:
+                p.threads()
+            except psutil.AccessDenied:
+                raise unittest.SkipTest(
+                    "on OpenBSD this requires root access")
+        self.assertAlmostEqual(
+            p.cpu_times().user,
+            sum([x.user_time for x in p.threads()]), delta=0.1)
+        self.assertAlmostEqual(
+            p.cpu_times().system,
+            sum([x.system_time for x in p.threads()]), delta=0.1)
+
+    def test_memory_info(self):
+        p = psutil.Process()
+
+        # step 1 - get a base value to compare our results
+        rss1, vms1 = p.memory_info()[:2]
+        percent1 = p.memory_percent()
+        self.assertGreater(rss1, 0)
+        self.assertGreater(vms1, 0)
+
+        # step 2 - allocate some memory
+        memarr = [None] * 1500000
+
+        rss2, vms2 = p.memory_info()[:2]
+        percent2 = p.memory_percent()
+
+        # step 3 - make sure that the memory usage bumped up
+        self.assertGreater(rss2, rss1)
+        self.assertGreaterEqual(vms2, vms1)  # vms might be equal
+        self.assertGreater(percent2, percent1)
+        del memarr
+
+        if WINDOWS:
+            mem = p.memory_info()
+            self.assertEqual(mem.rss, mem.wset)
+            self.assertEqual(mem.vms, mem.pagefile)
+
+        mem = p.memory_info()
+        for name in mem._fields:
+            self.assertGreaterEqual(getattr(mem, name), 0)
+
+    def test_memory_full_info(self):
+        total = psutil.virtual_memory().total
+        mem = psutil.Process().memory_full_info()
+        for name in mem._fields:
+            value = getattr(mem, name)
+            self.assertGreaterEqual(value, 0, msg=(name, value))
+            self.assertLessEqual(value, total, msg=(name, value, total))
+        if LINUX or WINDOWS or OSX:
+            self.assertGreaterEqual(mem.uss, 0)
+        if LINUX:
+            self.assertGreaterEqual(mem.pss, 0)
+            self.assertGreaterEqual(mem.swap, 0)
+
+    @unittest.skipIf(not HAS_MEMORY_MAPS, "not supported")
+    def test_memory_maps(self):
+        p = psutil.Process()
+        maps = p.memory_maps()
+        paths = [x for x in maps]
+        self.assertEqual(len(paths), len(set(paths)))
+        ext_maps = p.memory_maps(grouped=False)
+
+        for nt in maps:
+            if not nt.path.startswith('['):
+                assert os.path.isabs(nt.path), nt.path
+                if POSIX:
+                    try:
+                        assert os.path.exists(nt.path) or \
+                            os.path.islink(nt.path), nt.path
+                    except AssertionError:
+                        if not LINUX:
+                            raise
+                        else:
+                            # https://github.com/giampaolo/psutil/issues/759
+                            with open('/proc/self/smaps') as f:
+                                data = f.read()
+                            if "%s (deleted)" % nt.path not in data:
+                                raise
+                else:
+                    # XXX - On Windows we have this strange behavior with
+                    # 64 bit dlls: they are visible via explorer but cannot
+                    # be accessed via os.stat() (wtf?).
+                    if '64' not in os.path.basename(nt.path):
+                        assert os.path.exists(nt.path), nt.path
+        for nt in ext_maps:
+            for fname in nt._fields:
+                value = getattr(nt, fname)
+                if fname == 'path':
+                    continue
+                elif fname in ('addr', 'perms'):
+                    assert value, value
+                else:
+                    self.assertIsInstance(value, (int, long))
+                    assert value >= 0, value
+
+    @unittest.skipIf(not HAS_MEMORY_MAPS, "not supported")
+    def test_memory_maps_lists_lib(self):
+        # Make sure a newly loaded shared lib is listed.
+        with copyload_shared_lib() as path:
+            def normpath(p):
+                return os.path.realpath(os.path.normcase(p))
+            libpaths = [normpath(x.path)
+                        for x in psutil.Process().memory_maps()]
+            self.assertIn(normpath(path), libpaths)
+
+    def test_memory_percent(self):
+        p = psutil.Process()
+        ret = p.memory_percent()
+        assert 0 <= ret <= 100, ret
+        ret = p.memory_percent(memtype='vms')
+        assert 0 <= ret <= 100, ret
+        assert 0 <= ret <= 100, ret
+        self.assertRaises(ValueError, p.memory_percent, memtype="?!?")
+        if LINUX or OSX or WINDOWS:
+            ret = p.memory_percent(memtype='uss')
+            assert 0 <= ret <= 100, ret
+            assert 0 <= ret <= 100, ret
+
+    def test_is_running(self):
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        assert p.is_running()
+        assert p.is_running()
+        p.kill()
+        p.wait()
+        assert not p.is_running()
+        assert not p.is_running()
+
+    def test_exe(self):
+        sproc = get_test_subprocess()
+        exe = psutil.Process(sproc.pid).exe()
+        try:
+            self.assertEqual(exe, PYTHON_EXE)
+        except AssertionError:
+            if WINDOWS and len(exe) == len(PYTHON_EXE):
+                # on Windows we don't care about case sensitivity
+                normcase = os.path.normcase
+                self.assertEqual(normcase(exe), normcase(PYTHON_EXE))
+            else:
+                # certain platforms such as BSD are more accurate returning:
+                # "/usr/local/bin/python2.7"
+                # ...instead of:
+                # "/usr/local/bin/python"
+                # We do not want to consider this difference in accuracy
+                # an error.
+                ver = "%s.%s" % (sys.version_info[0], sys.version_info[1])
+                try:
+                    self.assertEqual(exe.replace(ver, ''),
+                                     PYTHON_EXE.replace(ver, ''))
+                except AssertionError:
+                    # Tipically OSX. Really not sure what to do here.
+                    pass
+
+        out = sh([exe, "-c", "import os; print('hey')"])
+        self.assertEqual(out, 'hey')
+
+    def test_cmdline(self):
+        cmdline = [PYTHON_EXE, "-c", "import time; time.sleep(60)"]
+        sproc = get_test_subprocess(cmdline)
+        try:
+            self.assertEqual(' '.join(psutil.Process(sproc.pid).cmdline()),
+                             ' '.join(cmdline))
+        except AssertionError:
+            # XXX - most of the times the underlying sysctl() call on Net
+            # and Open BSD returns a truncated string.
+            # Also /proc/pid/cmdline behaves the same so it looks
+            # like this is a kernel bug.
+            # XXX - AIX truncates long arguments in /proc/pid/cmdline
+            if NETBSD or OPENBSD or AIX:
+                self.assertEqual(
+                    psutil.Process(sproc.pid).cmdline()[0], PYTHON_EXE)
+            else:
+                raise
+
+    def test_name(self):
+        sproc = get_test_subprocess(PYTHON_EXE)
+        name = psutil.Process(sproc.pid).name().lower()
+        pyexe = os.path.basename(os.path.realpath(sys.executable)).lower()
+        assert pyexe.startswith(name), (pyexe, name)
+
+    # XXX
+    @unittest.skipIf(SUNOS, "broken on SUNOS")
+    @unittest.skipIf(AIX, "broken on AIX")
+    def test_prog_w_funky_name(self):
+        # Test that name(), exe() and cmdline() correctly handle programs
+        # with funky chars such as spaces and ")", see:
+        # https://github.com/giampaolo/psutil/issues/628
+
+        def rm():
+            # Try to limit occasional failures on Appveyor:
+            # https://ci.appveyor.com/project/giampaolo/psutil/build/1350/
+            #     job/lbo3bkju55le850n
+            try:
+                safe_rmpath(funky_path)
+            except OSError:
+                pass
+
+        funky_path = TESTFN + 'foo bar )'
+        create_exe(funky_path)
+        self.addCleanup(rm)
+        cmdline = [funky_path, "-c",
+                   "import time; [time.sleep(0.01) for x in range(3000)];"
+                   "arg1", "arg2", "", "arg3", ""]
+        sproc = get_test_subprocess(cmdline)
+        p = psutil.Process(sproc.pid)
+        # ...in order to try to prevent occasional failures on travis
+        if TRAVIS:
+            wait_for_pid(p.pid)
+        self.assertEqual(p.cmdline(), cmdline)
+        self.assertEqual(p.name(), os.path.basename(funky_path))
+        self.assertEqual(os.path.normcase(p.exe()),
+                         os.path.normcase(funky_path))
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_uids(self):
+        p = psutil.Process()
+        real, effective, saved = p.uids()
+        # os.getuid() refers to "real" uid
+        self.assertEqual(real, os.getuid())
+        # os.geteuid() refers to "effective" uid
+        self.assertEqual(effective, os.geteuid())
+        # No such thing as os.getsuid() ("saved" uid), but starting
+        # from python 2.7 we have os.getresuid() which returns all
+        # of them.
+        if hasattr(os, "getresuid"):
+            self.assertEqual(os.getresuid(), p.uids())
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_gids(self):
+        p = psutil.Process()
+        real, effective, saved = p.gids()
+        # os.getuid() refers to "real" uid
+        self.assertEqual(real, os.getgid())
+        # os.geteuid() refers to "effective" uid
+        self.assertEqual(effective, os.getegid())
+        # No such thing as os.getsgid() ("saved" gid), but starting
+        # from python 2.7 we have os.getresgid() which returns all
+        # of them.
+        if hasattr(os, "getresuid"):
+            self.assertEqual(os.getresgid(), p.gids())
+
+    def test_nice(self):
+        p = psutil.Process()
+        self.assertRaises(TypeError, p.nice, "str")
+        if WINDOWS:
+            try:
+                init = p.nice()
+                if sys.version_info > (3, 4):
+                    self.assertIsInstance(init, enum.IntEnum)
+                else:
+                    self.assertIsInstance(init, int)
+                self.assertEqual(init, psutil.NORMAL_PRIORITY_CLASS)
+                p.nice(psutil.HIGH_PRIORITY_CLASS)
+                self.assertEqual(p.nice(), psutil.HIGH_PRIORITY_CLASS)
+                p.nice(psutil.NORMAL_PRIORITY_CLASS)
+                self.assertEqual(p.nice(), psutil.NORMAL_PRIORITY_CLASS)
+            finally:
+                p.nice(psutil.NORMAL_PRIORITY_CLASS)
+        else:
+            first_nice = p.nice()
+            try:
+                if hasattr(os, "getpriority"):
+                    self.assertEqual(
+                        os.getpriority(os.PRIO_PROCESS, os.getpid()), p.nice())
+                p.nice(1)
+                self.assertEqual(p.nice(), 1)
+                if hasattr(os, "getpriority"):
+                    self.assertEqual(
+                        os.getpriority(os.PRIO_PROCESS, os.getpid()), p.nice())
+                # XXX - going back to previous nice value raises
+                # AccessDenied on OSX
+                if not OSX:
+                    p.nice(0)
+                    self.assertEqual(p.nice(), 0)
+            except psutil.AccessDenied:
+                pass
+            finally:
+                try:
+                    p.nice(first_nice)
+                except psutil.AccessDenied:
+                    pass
+
+    def test_status(self):
+        p = psutil.Process()
+        self.assertEqual(p.status(), psutil.STATUS_RUNNING)
+
+    def test_username(self):
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        username = p.username()
+        if WINDOWS:
+            domain, username = username.split('\\')
+            self.assertEqual(username, getpass.getuser())
+            if 'USERDOMAIN' in os.environ:
+                self.assertEqual(domain, os.environ['USERDOMAIN'])
+        else:
+            self.assertEqual(username, getpass.getuser())
+
+    def test_cwd(self):
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        self.assertEqual(p.cwd(), os.getcwd())
+
+    def test_cwd_2(self):
+        cmd = [PYTHON_EXE, "-c",
+               "import os, time; os.chdir('..'); time.sleep(60)"]
+        sproc = get_test_subprocess(cmd)
+        p = psutil.Process(sproc.pid)
+        call_until(p.cwd, "ret == os.path.dirname(os.getcwd())")
+
+    @unittest.skipIf(not HAS_CPU_AFFINITY, 'not supported')
+    def test_cpu_affinity(self):
+        p = psutil.Process()
+        initial = p.cpu_affinity()
+        assert initial, initial
+        self.addCleanup(p.cpu_affinity, initial)
+
+        if hasattr(os, "sched_getaffinity"):
+            self.assertEqual(initial, list(os.sched_getaffinity(p.pid)))
+        self.assertEqual(len(initial), len(set(initial)))
+
+        all_cpus = list(range(len(psutil.cpu_percent(percpu=True))))
+        # Work around travis failure:
+        # https://travis-ci.org/giampaolo/psutil/builds/284173194
+        for n in all_cpus if not TRAVIS else initial:
+            p.cpu_affinity([n])
+            self.assertEqual(p.cpu_affinity(), [n])
+            if hasattr(os, "sched_getaffinity"):
+                self.assertEqual(p.cpu_affinity(),
+                                 list(os.sched_getaffinity(p.pid)))
+            # also test num_cpu()
+            if hasattr(p, "num_cpu"):
+                self.assertEqual(p.cpu_affinity()[0], p.num_cpu())
+
+        # [] is an alias for "all eligible CPUs"; on Linux this may
+        # not be equal to all available CPUs, see:
+        # https://github.com/giampaolo/psutil/issues/956
+        p.cpu_affinity([])
+        if LINUX:
+            self.assertEqual(p.cpu_affinity(), p._proc._get_eligible_cpus())
+        else:
+            self.assertEqual(p.cpu_affinity(), all_cpus)
+        if hasattr(os, "sched_getaffinity"):
+            self.assertEqual(p.cpu_affinity(),
+                             list(os.sched_getaffinity(p.pid)))
+        #
+        self.assertRaises(TypeError, p.cpu_affinity, 1)
+        p.cpu_affinity(initial)
+        # it should work with all iterables, not only lists
+        p.cpu_affinity(set(all_cpus))
+        p.cpu_affinity(tuple(all_cpus))
+
+    @unittest.skipIf(not HAS_CPU_AFFINITY, 'not supported')
+    def test_cpu_affinity_errs(self):
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        invalid_cpu = [len(psutil.cpu_times(percpu=True)) + 10]
+        self.assertRaises(ValueError, p.cpu_affinity, invalid_cpu)
+        self.assertRaises(ValueError, p.cpu_affinity, range(10000, 11000))
+        self.assertRaises(TypeError, p.cpu_affinity, [0, "1"])
+        self.assertRaises(ValueError, p.cpu_affinity, [0, -1])
+
+    @unittest.skipIf(not HAS_CPU_AFFINITY, 'not supported')
+    def test_cpu_affinity_all_combinations(self):
+        p = psutil.Process()
+        initial = p.cpu_affinity()
+        assert initial, initial
+        self.addCleanup(p.cpu_affinity, initial)
+
+        # All possible CPU set combinations.
+        combos = []
+        for l in range(0, len(initial) + 1):
+            for subset in itertools.combinations(initial, l):
+                if subset:
+                    combos.append(list(subset))
+
+        for combo in combos:
+            p.cpu_affinity(combo)
+            self.assertEqual(p.cpu_affinity(), combo)
+
+    # TODO: #595
+    @unittest.skipIf(BSD, "broken on BSD")
+    # can't find any process file on Appveyor
+    @unittest.skipIf(APPVEYOR, "unreliable on APPVEYOR")
+    def test_open_files(self):
+        # current process
+        p = psutil.Process()
+        files = p.open_files()
+        self.assertFalse(TESTFN in files)
+        with open(TESTFN, 'wb') as f:
+            f.write(b'x' * 1024)
+            f.flush()
+            # give the kernel some time to see the new file
+            files = call_until(p.open_files, "len(ret) != %i" % len(files))
+            for file in files:
+                if file.path == TESTFN:
+                    if LINUX:
+                        self.assertEqual(file.position, 1024)
+                    break
+            else:
+                self.fail("no file found; files=%s" % repr(files))
+        for file in files:
+            assert os.path.isfile(file.path), file
+
+        # another process
+        cmdline = "import time; f = open(r'%s', 'r'); time.sleep(60);" % TESTFN
+        sproc = get_test_subprocess([PYTHON_EXE, "-c", cmdline])
+        p = psutil.Process(sproc.pid)
+
+        for x in range(100):
+            filenames = [x.path for x in p.open_files()]
+            if TESTFN in filenames:
+                break
+            time.sleep(.01)
+        else:
+            self.assertIn(TESTFN, filenames)
+        for file in filenames:
+            assert os.path.isfile(file), file
+
+    # TODO: #595
+    @unittest.skipIf(BSD, "broken on BSD")
+    # can't find any process file on Appveyor
+    @unittest.skipIf(APPVEYOR, "unreliable on APPVEYOR")
+    def test_open_files_2(self):
+        # test fd and path fields
+        with open(TESTFN, 'w') as fileobj:
+            p = psutil.Process()
+            for file in p.open_files():
+                if file.path == fileobj.name or file.fd == fileobj.fileno():
+                    break
+            else:
+                self.fail("no file found; files=%s" % repr(p.open_files()))
+            self.assertEqual(file.path, fileobj.name)
+            if WINDOWS:
+                self.assertEqual(file.fd, -1)
+            else:
+                self.assertEqual(file.fd, fileobj.fileno())
+            # test positions
+            ntuple = p.open_files()[0]
+            self.assertEqual(ntuple[0], ntuple.path)
+            self.assertEqual(ntuple[1], ntuple.fd)
+            # test file is gone
+            self.assertNotIn(fileobj.name, p.open_files())
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_num_fds(self):
+        p = psutil.Process()
+        start = p.num_fds()
+        file = open(TESTFN, 'w')
+        self.addCleanup(file.close)
+        self.assertEqual(p.num_fds(), start + 1)
+        sock = socket.socket()
+        self.addCleanup(sock.close)
+        self.assertEqual(p.num_fds(), start + 2)
+        file.close()
+        sock.close()
+        self.assertEqual(p.num_fds(), start)
+
+    @skip_on_not_implemented(only_if=LINUX)
+    @unittest.skipIf(OPENBSD or NETBSD, "not reliable on OPENBSD & NETBSD")
+    def test_num_ctx_switches(self):
+        p = psutil.Process()
+        before = sum(p.num_ctx_switches())
+        for x in range(500000):
+            after = sum(p.num_ctx_switches())
+            if after > before:
+                return
+        self.fail("num ctx switches still the same after 50.000 iterations")
+
+    def test_ppid(self):
+        if hasattr(os, 'getppid'):
+            self.assertEqual(psutil.Process().ppid(), os.getppid())
+        this_parent = os.getpid()
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        self.assertEqual(p.ppid(), this_parent)
+        # no other process is supposed to have us as parent
+        reap_children(recursive=True)
+        if APPVEYOR:
+            # Occasional failures, see:
+            # https://ci.appveyor.com/project/giampaolo/psutil/build/
+            #     job/0hs623nenj7w4m33
+            return
+        for p in psutil.process_iter():
+            if p.pid == sproc.pid:
+                continue
+            # XXX: sometimes this fails on Windows; not sure why.
+            self.assertNotEqual(p.ppid(), this_parent, msg=p)
+
+    def test_parent(self):
+        this_parent = os.getpid()
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        self.assertEqual(p.parent().pid, this_parent)
+
+    def test_parent_disappeared(self):
+        # Emulate a case where the parent process disappeared.
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        with mock.patch("psutil.Process",
+                        side_effect=psutil.NoSuchProcess(0, 'foo')):
+            self.assertIsNone(p.parent())
+
+    def test_children(self):
+        p = psutil.Process()
+        self.assertEqual(p.children(), [])
+        self.assertEqual(p.children(recursive=True), [])
+        # On Windows we set the flag to 0 in order to cancel out the
+        # CREATE_NO_WINDOW flag (enabled by default) which creates
+        # an extra "conhost.exe" child.
+        sproc = get_test_subprocess(creationflags=0)
+        children1 = p.children()
+        children2 = p.children(recursive=True)
+        for children in (children1, children2):
+            self.assertEqual(len(children), 1)
+            self.assertEqual(children[0].pid, sproc.pid)
+            self.assertEqual(children[0].ppid(), os.getpid())
+
+    def test_children_recursive(self):
+        # Test children() against two sub processes, p1 and p2, where
+        # p1 (our child) spawned p2 (our grandchild).
+        p1, p2 = create_proc_children_pair()
+        p = psutil.Process()
+        self.assertEqual(p.children(), [p1])
+        self.assertEqual(p.children(recursive=True), [p1, p2])
+        # If the intermediate process is gone there's no way for
+        # children() to recursively find it.
+        p1.terminate()
+        p1.wait()
+        self.assertEqual(p.children(recursive=True), [])
+
+    def test_children_duplicates(self):
+        # find the process which has the highest number of children
+        table = collections.defaultdict(int)
+        for p in psutil.process_iter():
+            try:
+                table[p.ppid()] += 1
+            except psutil.Error:
+                pass
+        # this is the one, now let's make sure there are no duplicates
+        pid = sorted(table.items(), key=lambda x: x[1])[-1][0]
+        p = psutil.Process(pid)
+        try:
+            c = p.children(recursive=True)
+        except psutil.AccessDenied:  # windows
+            pass
+        else:
+            self.assertEqual(len(c), len(set(c)))
+
+    def test_suspend_resume(self):
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        p.suspend()
+        for x in range(100):
+            if p.status() == psutil.STATUS_STOPPED:
+                break
+            time.sleep(0.01)
+        p.resume()
+        self.assertNotEqual(p.status(), psutil.STATUS_STOPPED)
+
+    def test_invalid_pid(self):
+        self.assertRaises(TypeError, psutil.Process, "1")
+        self.assertRaises(ValueError, psutil.Process, -1)
+
+    def test_as_dict(self):
+        p = psutil.Process()
+        d = p.as_dict(attrs=['exe', 'name'])
+        self.assertEqual(sorted(d.keys()), ['exe', 'name'])
+
+        p = psutil.Process(min(psutil.pids()))
+        d = p.as_dict(attrs=['connections'], ad_value='foo')
+        if not isinstance(d['connections'], list):
+            self.assertEqual(d['connections'], 'foo')
+
+        # Test ad_value is set on AccessDenied.
+        with mock.patch('psutil.Process.nice', create=True,
+                        side_effect=psutil.AccessDenied):
+            self.assertEqual(
+                p.as_dict(attrs=["nice"], ad_value=1), {"nice": 1})
+
+        # Test that NoSuchProcess bubbles up.
+        with mock.patch('psutil.Process.nice', create=True,
+                        side_effect=psutil.NoSuchProcess(p.pid, "name")):
+            self.assertRaises(
+                psutil.NoSuchProcess, p.as_dict, attrs=["nice"])
+
+        # Test that ZombieProcess is swallowed.
+        with mock.patch('psutil.Process.nice', create=True,
+                        side_effect=psutil.ZombieProcess(p.pid, "name")):
+            self.assertEqual(
+                p.as_dict(attrs=["nice"], ad_value="foo"), {"nice": "foo"})
+
+        # By default APIs raising NotImplementedError are
+        # supposed to be skipped.
+        with mock.patch('psutil.Process.nice', create=True,
+                        side_effect=NotImplementedError):
+            d = p.as_dict()
+            self.assertNotIn('nice', list(d.keys()))
+            # ...unless the user explicitly asked for some attr.
+            with self.assertRaises(NotImplementedError):
+                p.as_dict(attrs=["nice"])
+
+        # errors
+        with self.assertRaises(TypeError):
+            p.as_dict('name')
+        with self.assertRaises(ValueError):
+            p.as_dict(['foo'])
+        with self.assertRaises(ValueError):
+            p.as_dict(['foo', 'bar'])
+
+    def test_oneshot(self):
+        with mock.patch("psutil._psplatform.Process.cpu_times") as m:
+            p = psutil.Process()
+            with p.oneshot():
+                p.cpu_times()
+                p.cpu_times()
+            self.assertEqual(m.call_count, 1)
+
+        with mock.patch("psutil._psplatform.Process.cpu_times") as m:
+            p.cpu_times()
+            p.cpu_times()
+        self.assertEqual(m.call_count, 2)
+
+    def test_oneshot_twice(self):
+        # Test the case where the ctx manager is __enter__ed twice.
+        # The second __enter__ is supposed to resut in a NOOP.
+        with mock.patch("psutil._psplatform.Process.cpu_times") as m1:
+            with mock.patch("psutil._psplatform.Process.oneshot_enter") as m2:
+                p = psutil.Process()
+                with p.oneshot():
+                    p.cpu_times()
+                    p.cpu_times()
+                    with p.oneshot():
+                        p.cpu_times()
+                        p.cpu_times()
+                self.assertEqual(m1.call_count, 1)
+                self.assertEqual(m2.call_count, 1)
+
+        with mock.patch("psutil._psplatform.Process.cpu_times") as m:
+            p.cpu_times()
+            p.cpu_times()
+        self.assertEqual(m.call_count, 2)
+
+    def test_halfway_terminated_process(self):
+        # Test that NoSuchProcess exception gets raised in case the
+        # process dies after we create the Process object.
+        # Example:
+        #  >>> proc = Process(1234)
+        # >>> time.sleep(2)  # time-consuming task, process dies in meantime
+        #  >>> proc.name()
+        # Refers to Issue #15
+        sproc = get_test_subprocess()
+        p = psutil.Process(sproc.pid)
+        p.terminate()
+        p.wait()
+        if WINDOWS:
+            call_until(psutil.pids, "%s not in ret" % p.pid)
+        self.assertFalse(p.is_running())
+        # self.assertFalse(p.pid in psutil.pids(), msg="retcode = %s" %
+        #   retcode)
+
+        excluded_names = ['pid', 'is_running', 'wait', 'create_time',
+                          'oneshot', 'memory_info_ex']
+        if LINUX and not HAS_RLIMIT:
+            excluded_names.append('rlimit')
+        for name in dir(p):
+            if (name.startswith('_') or
+                    name in excluded_names):
+                continue
+            try:
+                meth = getattr(p, name)
+                # get/set methods
+                if name == 'nice':
+                    if POSIX:
+                        ret = meth(1)
+                    else:
+                        ret = meth(psutil.NORMAL_PRIORITY_CLASS)
+                elif name == 'ionice':
+                    ret = meth()
+                    ret = meth(2)
+                elif name == 'rlimit':
+                    ret = meth(psutil.RLIMIT_NOFILE)
+                    ret = meth(psutil.RLIMIT_NOFILE, (5, 5))
+                elif name == 'cpu_affinity':
+                    ret = meth()
+                    ret = meth([0])
+                elif name == 'send_signal':
+                    ret = meth(signal.SIGTERM)
+                else:
+                    ret = meth()
+            except psutil.ZombieProcess:
+                self.fail("ZombieProcess for %r was not supposed to happen" %
+                          name)
+            except psutil.NoSuchProcess:
+                pass
+            except psutil.AccessDenied:
+                if OPENBSD and name in ('threads', 'num_threads'):
+                    pass
+                else:
+                    raise
+            except NotImplementedError:
+                pass
+            else:
+                self.fail(
+                    "NoSuchProcess exception not raised for %r, retval=%s" % (
+                        name, ret))
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_zombie_process(self):
+        def succeed_or_zombie_p_exc(fun, *args, **kwargs):
+            try:
+                return fun(*args, **kwargs)
+            except (psutil.ZombieProcess, psutil.AccessDenied):
+                pass
+
+        zpid = create_zombie_proc()
+        self.addCleanup(reap_children, recursive=True)
+        # A zombie process should always be instantiable
+        zproc = psutil.Process(zpid)
+        # ...and at least its status always be querable
+        self.assertEqual(zproc.status(), psutil.STATUS_ZOMBIE)
+        # ...and it should be considered 'running'
+        self.assertTrue(zproc.is_running())
+        # ...and as_dict() shouldn't crash
+        zproc.as_dict()
+        # if cmdline succeeds it should be an empty list
+        ret = succeed_or_zombie_p_exc(zproc.suspend)
+        if ret is not None:
+            self.assertEqual(ret, [])
+
+        if hasattr(zproc, "rlimit"):
+            succeed_or_zombie_p_exc(zproc.rlimit, psutil.RLIMIT_NOFILE)
+            succeed_or_zombie_p_exc(zproc.rlimit, psutil.RLIMIT_NOFILE,
+                                    (5, 5))
+        # set methods
+        succeed_or_zombie_p_exc(zproc.parent)
+        if hasattr(zproc, 'cpu_affinity'):
+            try:
+                succeed_or_zombie_p_exc(zproc.cpu_affinity, [0])
+            except ValueError as err:
+                if TRAVIS and LINUX and "not eligible" in str(err):
+                    # https://travis-ci.org/giampaolo/psutil/jobs/279890461
+                    pass
+                else:
+                    raise
+
+        succeed_or_zombie_p_exc(zproc.nice, 0)
+        if hasattr(zproc, 'ionice'):
+            if LINUX:
+                succeed_or_zombie_p_exc(zproc.ionice, 2, 0)
+            else:
+                succeed_or_zombie_p_exc(zproc.ionice, 0)  # Windows
+        if hasattr(zproc, 'rlimit'):
+            succeed_or_zombie_p_exc(zproc.rlimit,
+                                    psutil.RLIMIT_NOFILE, (5, 5))
+        succeed_or_zombie_p_exc(zproc.suspend)
+        succeed_or_zombie_p_exc(zproc.resume)
+        succeed_or_zombie_p_exc(zproc.terminate)
+        succeed_or_zombie_p_exc(zproc.kill)
+
+        # ...its parent should 'see' it
+        # edit: not true on BSD and OSX
+        # descendants = [x.pid for x in psutil.Process().children(
+        #                recursive=True)]
+        # self.assertIn(zpid, descendants)
+        # XXX should we also assume ppid be usable?  Note: this
+        # would be an important use case as the only way to get
+        # rid of a zombie is to kill its parent.
+        # self.assertEqual(zpid.ppid(), os.getpid())
+        # ...and all other APIs should be able to deal with it
+        self.assertTrue(psutil.pid_exists(zpid))
+        if not TRAVIS and OSX:
+            # For some reason this started failing all of the sudden.
+            # Maybe they upgraded OSX version?
+            # https://travis-ci.org/giampaolo/psutil/jobs/310896404
+            self.assertIn(zpid, psutil.pids())
+            self.assertIn(zpid, [x.pid for x in psutil.process_iter()])
+            psutil._pmap = {}
+            self.assertIn(zpid, [x.pid for x in psutil.process_iter()])
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_zombie_process_is_running_w_exc(self):
+        # Emulate a case where internally is_running() raises
+        # ZombieProcess.
+        p = psutil.Process()
+        with mock.patch("psutil.Process",
+                        side_effect=psutil.ZombieProcess(0)) as m:
+            assert p.is_running()
+            assert m.called
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_zombie_process_status_w_exc(self):
+        # Emulate a case where internally status() raises
+        # ZombieProcess.
+        p = psutil.Process()
+        with mock.patch("psutil._psplatform.Process.status",
+                        side_effect=psutil.ZombieProcess(0)) as m:
+            self.assertEqual(p.status(), psutil.STATUS_ZOMBIE)
+            assert m.called
+
+    def test_pid_0(self):
+        # Process(0) is supposed to work on all platforms except Linux
+        if 0 not in psutil.pids():
+            self.assertRaises(psutil.NoSuchProcess, psutil.Process, 0)
+            return
+
+        # test all methods
+        p = psutil.Process(0)
+        for name in psutil._as_dict_attrnames:
+            if name == 'pid':
+                continue
+            meth = getattr(p, name)
+            try:
+                ret = meth()
+            except psutil.AccessDenied:
+                pass
+            else:
+                if name in ("uids", "gids"):
+                    self.assertEqual(ret.real, 0)
+                elif name == "username":
+                    if POSIX:
+                        self.assertEqual(p.username(), 'root')
+                    elif WINDOWS:
+                        self.assertEqual(p.username(), 'NT AUTHORITY\\SYSTEM')
+                elif name == "name":
+                    assert name, name
+
+        if hasattr(p, 'rlimit'):
+            try:
+                p.rlimit(psutil.RLIMIT_FSIZE)
+            except psutil.AccessDenied:
+                pass
+
+        p.as_dict()
+
+        if not OPENBSD:
+            self.assertIn(0, psutil.pids())
+            self.assertTrue(psutil.pid_exists(0))
+
+    @unittest.skipIf(not HAS_ENVIRON, "not supported")
+    def test_environ(self):
+        def clean_dict(d):
+            # Most of these are problematic on Travis.
+            d.pop("PSUTIL_TESTING", None)
+            d.pop("PLAT", None)
+            d.pop("HOME", None)
+            if OSX:
+                d.pop("__CF_USER_TEXT_ENCODING", None)
+                d.pop("VERSIONER_PYTHON_PREFER_32_BIT", None)
+                d.pop("VERSIONER_PYTHON_VERSION", None)
+            return dict(
+                [(k.replace("\r", "").replace("\n", ""),
+                  v.replace("\r", "").replace("\n", ""))
+                 for k, v in d.items()])
+
+        self.maxDiff = None
+        p = psutil.Process()
+        d1 = clean_dict(p.environ())
+        d2 = clean_dict(os.environ.copy())
+        self.assertEqual(d1, d2)
+
+    @unittest.skipIf(not HAS_ENVIRON, "not supported")
+    @unittest.skipIf(not POSIX, "POSIX only")
+    def test_weird_environ(self):
+        # environment variables can contain values without an equals sign
+        code = textwrap.dedent("""
+            #include <unistd.h>
+            #include <fcntl.h>
+            char * const argv[] = {"cat", 0};
+            char * const envp[] = {"A=1", "X", "C=3", 0};
+            int main(void) {
+                /* Close stderr on exec so parent can wait for the execve to
+                 * finish. */
+                if (fcntl(2, F_SETFD, FD_CLOEXEC) != 0)
+                    return 0;
+                return execve("/bin/cat", argv, envp);
+            }
+            """)
+        path = TESTFN
+        create_exe(path, c_code=code)
+        self.addCleanup(safe_rmpath, path)
+        sproc = get_test_subprocess([path],
+                                    stdin=subprocess.PIPE,
+                                    stderr=subprocess.PIPE)
+        p = psutil.Process(sproc.pid)
+        wait_for_pid(p.pid)
+        self.assertTrue(p.is_running())
+        # Wait for process to exec or exit.
+        self.assertEqual(sproc.stderr.read(), b"")
+        self.assertEqual(p.environ(), {"A": "1", "C": "3"})
+        sproc.communicate()
+        self.assertEqual(sproc.returncode, 0)
+
+
+# ===================================================================
+# --- Limited user tests
+# ===================================================================
+
+
+if POSIX and os.getuid() == 0:
+    class LimitedUserTestCase(TestProcess):
+        """Repeat the previous tests by using a limited user.
+        Executed only on UNIX and only if the user who run the test script
+        is root.
+        """
+        # the uid/gid the test suite runs under
+        if hasattr(os, 'getuid'):
+            PROCESS_UID = os.getuid()
+            PROCESS_GID = os.getgid()
+
+        def __init__(self, *args, **kwargs):
+            TestProcess.__init__(self, *args, **kwargs)
+            # re-define all existent test methods in order to
+            # ignore AccessDenied exceptions
+            for attr in [x for x in dir(self) if x.startswith('test')]:
+                meth = getattr(self, attr)
+
+                def test_(self):
+                    try:
+                        meth()
+                    except psutil.AccessDenied:
+                        pass
+                setattr(self, attr, types.MethodType(test_, self))
+
+        def setUp(self):
+            safe_rmpath(TESTFN)
+            TestProcess.setUp(self)
+            os.setegid(1000)
+            os.seteuid(1000)
+
+        def tearDown(self):
+            os.setegid(self.PROCESS_UID)
+            os.seteuid(self.PROCESS_GID)
+            TestProcess.tearDown(self)
+
+        def test_nice(self):
+            try:
+                psutil.Process().nice(-1)
+            except psutil.AccessDenied:
+                pass
+            else:
+                self.fail("exception not raised")
+
+        def test_zombie_process(self):
+            # causes problems if test test suite is run as root
+            pass
+
+
+# ===================================================================
+# --- psutil.Popen tests
+# ===================================================================
+
+
+class TestPopen(unittest.TestCase):
+    """Tests for psutil.Popen class."""
+
+    def tearDown(self):
+        reap_children()
+
+    def test_misc(self):
+        # XXX this test causes a ResourceWarning on Python 3 because
+        # psutil.__subproc instance doesn't get propertly freed.
+        # Not sure what to do though.
+        cmd = [PYTHON_EXE, "-c", "import time; time.sleep(60);"]
+        with psutil.Popen(cmd, stdout=subprocess.PIPE,
+                          stderr=subprocess.PIPE) as proc:
+            proc.name()
+            proc.cpu_times()
+            proc.stdin
+            self.assertTrue(dir(proc))
+            self.assertRaises(AttributeError, getattr, proc, 'foo')
+            proc.terminate()
+
+    def test_ctx_manager(self):
+        with psutil.Popen([PYTHON_EXE, "-V"],
+                          stdout=subprocess.PIPE,
+                          stderr=subprocess.PIPE,
+                          stdin=subprocess.PIPE) as proc:
+            proc.communicate()
+        assert proc.stdout.closed
+        assert proc.stderr.closed
+        assert proc.stdin.closed
+        self.assertEqual(proc.returncode, 0)
+
+    def test_kill_terminate(self):
+        # subprocess.Popen()'s terminate(), kill() and send_signal() do
+        # not raise exception after the process is gone. psutil.Popen
+        # diverges from that.
+        cmd = [PYTHON_EXE, "-c", "import time; time.sleep(60);"]
+        with psutil.Popen(cmd, stdout=subprocess.PIPE,
+                          stderr=subprocess.PIPE) as proc:
+            proc.terminate()
+            proc.wait()
+            self.assertRaises(psutil.NoSuchProcess, proc.terminate)
+            self.assertRaises(psutil.NoSuchProcess, proc.kill)
+            self.assertRaises(psutil.NoSuchProcess, proc.send_signal,
+                              signal.SIGTERM)
+            if WINDOWS and sys.version_info >= (2, 7):
+                self.assertRaises(psutil.NoSuchProcess, proc.send_signal,
+                                  signal.CTRL_C_EVENT)
+                self.assertRaises(psutil.NoSuchProcess, proc.send_signal,
+                                  signal.CTRL_BREAK_EVENT)
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_sunos.py b/psutil/tests/test_sunos.py
new file mode 100755
index 00000000..ea9afcde
--- /dev/null
+++ b/psutil/tests/test_sunos.py
@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Sun OS specific tests."""
+
+import os
+
+import psutil
+from psutil import SUNOS
+from psutil.tests import run_test_module_by_name
+from psutil.tests import sh
+from psutil.tests import unittest
+
+
+@unittest.skipIf(not SUNOS, "SUNOS only")
+class SunOSSpecificTestCase(unittest.TestCase):
+
+    def test_swap_memory(self):
+        out = sh('env PATH=/usr/sbin:/sbin:%s swap -l' % os.environ['PATH'])
+        lines = out.strip().split('\n')[1:]
+        if not lines:
+            raise ValueError('no swap device(s) configured')
+        total = free = 0
+        for line in lines:
+            line = line.split()
+            t, f = line[-2:]
+            total += int(int(t) * 512)
+            free += int(int(f) * 512)
+        used = total - free
+
+        psutil_swap = psutil.swap_memory()
+        self.assertEqual(psutil_swap.total, total)
+        self.assertEqual(psutil_swap.used, used)
+        self.assertEqual(psutil_swap.free, free)
+
+    def test_cpu_count(self):
+        out = sh("/usr/sbin/psrinfo")
+        self.assertEqual(psutil.cpu_count(), len(out.split('\n')))
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_system.py b/psutil/tests/test_system.py
new file mode 100755
index 00000000..20b132a9
--- /dev/null
+++ b/psutil/tests/test_system.py
@@ -0,0 +1,862 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Tests for system APIS."""
+
+import contextlib
+import datetime
+import errno
+import os
+import pprint
+import shutil
+import signal
+import socket
+import sys
+import tempfile
+import time
+
+import psutil
+from psutil import AIX
+from psutil import BSD
+from psutil import FREEBSD
+from psutil import LINUX
+from psutil import NETBSD
+from psutil import OPENBSD
+from psutil import OSX
+from psutil import POSIX
+from psutil import SUNOS
+from psutil import WINDOWS
+from psutil._compat import long
+from psutil.tests import APPVEYOR
+from psutil.tests import ASCII_FS
+from psutil.tests import check_net_address
+from psutil.tests import DEVNULL
+from psutil.tests import enum
+from psutil.tests import get_test_subprocess
+from psutil.tests import HAS_BATTERY
+from psutil.tests import HAS_CPU_FREQ
+from psutil.tests import HAS_SENSORS_BATTERY
+from psutil.tests import HAS_SENSORS_FANS
+from psutil.tests import HAS_SENSORS_TEMPERATURES
+from psutil.tests import mock
+from psutil.tests import reap_children
+from psutil.tests import retry_before_failing
+from psutil.tests import run_test_module_by_name
+from psutil.tests import safe_rmpath
+from psutil.tests import TESTFN
+from psutil.tests import TESTFN_UNICODE
+from psutil.tests import TRAVIS
+from psutil.tests import unittest
+
+
+# ===================================================================
+# --- System-related API tests
+# ===================================================================
+
+
+class TestSystemAPIs(unittest.TestCase):
+    """Tests for system-related APIs."""
+
+    def setUp(self):
+        safe_rmpath(TESTFN)
+
+    def tearDown(self):
+        reap_children()
+
+    def test_process_iter(self):
+        self.assertIn(os.getpid(), [x.pid for x in psutil.process_iter()])
+        sproc = get_test_subprocess()
+        self.assertIn(sproc.pid, [x.pid for x in psutil.process_iter()])
+        p = psutil.Process(sproc.pid)
+        p.kill()
+        p.wait()
+        self.assertNotIn(sproc.pid, [x.pid for x in psutil.process_iter()])
+
+        with mock.patch('psutil.Process',
+                        side_effect=psutil.NoSuchProcess(os.getpid())):
+            self.assertEqual(list(psutil.process_iter()), [])
+        with mock.patch('psutil.Process',
+                        side_effect=psutil.AccessDenied(os.getpid())):
+            with self.assertRaises(psutil.AccessDenied):
+                list(psutil.process_iter())
+
+    def test_prcess_iter_w_params(self):
+        for p in psutil.process_iter(attrs=['pid']):
+            self.assertEqual(list(p.info.keys()), ['pid'])
+        with self.assertRaises(ValueError):
+            list(psutil.process_iter(attrs=['foo']))
+        with mock.patch("psutil._psplatform.Process.cpu_times",
+                        side_effect=psutil.AccessDenied(0, "")) as m:
+            for p in psutil.process_iter(attrs=["pid", "cpu_times"]):
+                self.assertIsNone(p.info['cpu_times'])
+                self.assertGreaterEqual(p.info['pid'], 0)
+            assert m.called
+        with mock.patch("psutil._psplatform.Process.cpu_times",
+                        side_effect=psutil.AccessDenied(0, "")) as m:
+            flag = object()
+            for p in psutil.process_iter(
+                    attrs=["pid", "cpu_times"], ad_value=flag):
+                self.assertIs(p.info['cpu_times'], flag)
+                self.assertGreaterEqual(p.info['pid'], 0)
+            assert m.called
+
+    def test_wait_procs(self):
+        def callback(p):
+            pids.append(p.pid)
+
+        pids = []
+        sproc1 = get_test_subprocess()
+        sproc2 = get_test_subprocess()
+        sproc3 = get_test_subprocess()
+        procs = [psutil.Process(x.pid) for x in (sproc1, sproc2, sproc3)]
+        self.assertRaises(ValueError, psutil.wait_procs, procs, timeout=-1)
+        self.assertRaises(TypeError, psutil.wait_procs, procs, callback=1)
+        t = time.time()
+        gone, alive = psutil.wait_procs(procs, timeout=0.01, callback=callback)
+
+        self.assertLess(time.time() - t, 0.5)
+        self.assertEqual(gone, [])
+        self.assertEqual(len(alive), 3)
+        self.assertEqual(pids, [])
+        for p in alive:
+            self.assertFalse(hasattr(p, 'returncode'))
+
+        @retry_before_failing(30)
+        def test(procs, callback):
+            gone, alive = psutil.wait_procs(procs, timeout=0.03,
+                                            callback=callback)
+            self.assertEqual(len(gone), 1)
+            self.assertEqual(len(alive), 2)
+            return gone, alive
+
+        sproc3.terminate()
+        gone, alive = test(procs, callback)
+        self.assertIn(sproc3.pid, [x.pid for x in gone])
+        if POSIX:
+            self.assertEqual(gone.pop().returncode, -signal.SIGTERM)
+        else:
+            self.assertEqual(gone.pop().returncode, 1)
+        self.assertEqual(pids, [sproc3.pid])
+        for p in alive:
+            self.assertFalse(hasattr(p, 'returncode'))
+
+        @retry_before_failing(30)
+        def test(procs, callback):
+            gone, alive = psutil.wait_procs(procs, timeout=0.03,
+                                            callback=callback)
+            self.assertEqual(len(gone), 3)
+            self.assertEqual(len(alive), 0)
+            return gone, alive
+
+        sproc1.terminate()
+        sproc2.terminate()
+        gone, alive = test(procs, callback)
+        self.assertEqual(set(pids), set([sproc1.pid, sproc2.pid, sproc3.pid]))
+        for p in gone:
+            self.assertTrue(hasattr(p, 'returncode'))
+
+    def test_wait_procs_no_timeout(self):
+        sproc1 = get_test_subprocess()
+        sproc2 = get_test_subprocess()
+        sproc3 = get_test_subprocess()
+        procs = [psutil.Process(x.pid) for x in (sproc1, sproc2, sproc3)]
+        for p in procs:
+            p.terminate()
+        gone, alive = psutil.wait_procs(procs)
+
+    def test_boot_time(self):
+        bt = psutil.boot_time()
+        self.assertIsInstance(bt, float)
+        self.assertGreater(bt, 0)
+        self.assertLess(bt, time.time())
+
+    @unittest.skipIf(not POSIX, 'POSIX only')
+    def test_PAGESIZE(self):
+        # pagesize is used internally to perform different calculations
+        # and it's determined by using SC_PAGE_SIZE; make sure
+        # getpagesize() returns the same value.
+        import resource
+        self.assertEqual(os.sysconf("SC_PAGE_SIZE"), resource.getpagesize())
+
+    def test_virtual_memory(self):
+        mem = psutil.virtual_memory()
+        assert mem.total > 0, mem
+        assert mem.available > 0, mem
+        assert 0 <= mem.percent <= 100, mem
+        assert mem.used > 0, mem
+        assert mem.free >= 0, mem
+        for name in mem._fields:
+            value = getattr(mem, name)
+            if name != 'percent':
+                self.assertIsInstance(value, (int, long))
+            if name != 'total':
+                if not value >= 0:
+                    self.fail("%r < 0 (%s)" % (name, value))
+                if value > mem.total:
+                    self.fail("%r > total (total=%s, %s=%s)"
+                              % (name, mem.total, name, value))
+
+    def test_swap_memory(self):
+        mem = psutil.swap_memory()
+        self.assertEqual(
+            mem._fields, ('total', 'used', 'free', 'percent', 'sin', 'sout'))
+
+        assert mem.total >= 0, mem
+        assert mem.used >= 0, mem
+        if mem.total > 0:
+            # likely a system with no swap partition
+            assert mem.free > 0, mem
+        else:
+            assert mem.free == 0, mem
+        assert 0 <= mem.percent <= 100, mem
+        assert mem.sin >= 0, mem
+        assert mem.sout >= 0, mem
+
+    def test_pid_exists(self):
+        sproc = get_test_subprocess()
+        self.assertTrue(psutil.pid_exists(sproc.pid))
+        p = psutil.Process(sproc.pid)
+        p.kill()
+        p.wait()
+        self.assertFalse(psutil.pid_exists(sproc.pid))
+        self.assertFalse(psutil.pid_exists(-1))
+        self.assertEqual(psutil.pid_exists(0), 0 in psutil.pids())
+
+    def test_pid_exists_2(self):
+        reap_children()
+        pids = psutil.pids()
+        for pid in pids:
+            try:
+                assert psutil.pid_exists(pid)
+            except AssertionError:
+                # in case the process disappeared in meantime fail only
+                # if it is no longer in psutil.pids()
+                time.sleep(.1)
+                if pid in psutil.pids():
+                    self.fail(pid)
+        pids = range(max(pids) + 5000, max(pids) + 6000)
+        for pid in pids:
+            self.assertFalse(psutil.pid_exists(pid), msg=pid)
+
+    def test_pids(self):
+        plist = [x.pid for x in psutil.process_iter()]
+        pidlist = psutil.pids()
+        self.assertEqual(plist.sort(), pidlist.sort())
+        # make sure every pid is unique
+        self.assertEqual(len(pidlist), len(set(pidlist)))
+
+    def test_test(self):
+        # test for psutil.test() function
+        stdout = sys.stdout
+        sys.stdout = DEVNULL
+        try:
+            psutil.test()
+        finally:
+            sys.stdout = stdout
+
+    def test_cpu_count(self):
+        logical = psutil.cpu_count()
+        self.assertEqual(logical, len(psutil.cpu_times(percpu=True)))
+        self.assertGreaterEqual(logical, 1)
+        #
+        if os.path.exists("/proc/cpuinfo"):
+            with open("/proc/cpuinfo") as fd:
+                cpuinfo_data = fd.read()
+            if "physical id" not in cpuinfo_data:
+                raise unittest.SkipTest("cpuinfo doesn't include physical id")
+        physical = psutil.cpu_count(logical=False)
+        self.assertGreaterEqual(physical, 1)
+        self.assertGreaterEqual(logical, physical)
+
+    def test_cpu_count_none(self):
+        # https://github.com/giampaolo/psutil/issues/1085
+        for val in (-1, 0, None):
+            with mock.patch('psutil._psplatform.cpu_count_logical',
+                            return_value=val) as m:
+                self.assertIsNone(psutil.cpu_count())
+                assert m.called
+            with mock.patch('psutil._psplatform.cpu_count_physical',
+                            return_value=val) as m:
+                self.assertIsNone(psutil.cpu_count(logical=False))
+                assert m.called
+
+    def test_cpu_times(self):
+        # Check type, value >= 0, str().
+        total = 0
+        times = psutil.cpu_times()
+        sum(times)
+        for cp_time in times:
+            self.assertIsInstance(cp_time, float)
+            self.assertGreaterEqual(cp_time, 0.0)
+            total += cp_time
+        self.assertEqual(total, sum(times))
+        str(times)
+        # CPU times are always supposed to increase over time
+        # or at least remain the same and that's because time
+        # cannot go backwards.
+        # Surprisingly sometimes this might not be the case (at
+        # least on Windows and Linux), see:
+        # https://github.com/giampaolo/psutil/issues/392
+        # https://github.com/giampaolo/psutil/issues/645
+        # if not WINDOWS:
+        #     last = psutil.cpu_times()
+        #     for x in range(100):
+        #         new = psutil.cpu_times()
+        #         for field in new._fields:
+        #             new_t = getattr(new, field)
+        #             last_t = getattr(last, field)
+        #             self.assertGreaterEqual(new_t, last_t,
+        #                                     msg="%s %s" % (new_t, last_t))
+        #         last = new
+
+    def test_cpu_times_time_increases(self):
+        # Make sure time increases between calls.
+        t1 = sum(psutil.cpu_times())
+        time.sleep(0.1)
+        t2 = sum(psutil.cpu_times())
+        difference = t2 - t1
+        if not difference >= 0.05:
+            self.fail("difference %s" % difference)
+
+    def test_per_cpu_times(self):
+        # Check type, value >= 0, str().
+        for times in psutil.cpu_times(percpu=True):
+            total = 0
+            sum(times)
+            for cp_time in times:
+                self.assertIsInstance(cp_time, float)
+                self.assertGreaterEqual(cp_time, 0.0)
+                total += cp_time
+            self.assertEqual(total, sum(times))
+            str(times)
+        self.assertEqual(len(psutil.cpu_times(percpu=True)[0]),
+                         len(psutil.cpu_times(percpu=False)))
+
+        # Note: in theory CPU times are always supposed to increase over
+        # time or remain the same but never go backwards. In practice
+        # sometimes this is not the case.
+        # This issue seemd to be afflict Windows:
+        # https://github.com/giampaolo/psutil/issues/392
+        # ...but it turns out also Linux (rarely) behaves the same.
+        # last = psutil.cpu_times(percpu=True)
+        # for x in range(100):
+        #     new = psutil.cpu_times(percpu=True)
+        #     for index in range(len(new)):
+        #         newcpu = new[index]
+        #         lastcpu = last[index]
+        #         for field in newcpu._fields:
+        #             new_t = getattr(newcpu, field)
+        #             last_t = getattr(lastcpu, field)
+        #             self.assertGreaterEqual(
+        #                 new_t, last_t, msg="%s %s" % (lastcpu, newcpu))
+        #     last = new
+
+    def test_per_cpu_times_2(self):
+        # Simulate some work load then make sure time have increased
+        # between calls.
+        tot1 = psutil.cpu_times(percpu=True)
+        stop_at = time.time() + 0.1
+        while True:
+            if time.time() >= stop_at:
+                break
+        tot2 = psutil.cpu_times(percpu=True)
+        for t1, t2 in zip(tot1, tot2):
+            t1, t2 = sum(t1), sum(t2)
+            difference = t2 - t1
+            if difference >= 0.05:
+                return
+        self.fail()
+
+    def test_cpu_times_comparison(self):
+        # Make sure the sum of all per cpu times is almost equal to
+        # base "one cpu" times.
+        base = psutil.cpu_times()
+        per_cpu = psutil.cpu_times(percpu=True)
+        summed_values = base._make([sum(num) for num in zip(*per_cpu)])
+        for field in base._fields:
+            self.assertAlmostEqual(
+                getattr(base, field), getattr(summed_values, field), delta=1)
+
+    def _test_cpu_percent(self, percent, last_ret, new_ret):
+        try:
+            self.assertIsInstance(percent, float)
+            self.assertGreaterEqual(percent, 0.0)
+            self.assertIsNot(percent, -0.0)
+            self.assertLessEqual(percent, 100.0 * psutil.cpu_count())
+        except AssertionError as err:
+            raise AssertionError("\n%s\nlast=%s\nnew=%s" % (
+                err, pprint.pformat(last_ret), pprint.pformat(new_ret)))
+
+    def test_cpu_percent(self):
+        last = psutil.cpu_percent(interval=0.001)
+        for x in range(100):
+            new = psutil.cpu_percent(interval=None)
+            self._test_cpu_percent(new, last, new)
+            last = new
+        with self.assertRaises(ValueError):
+            psutil.cpu_percent(interval=-1)
+
+    def test_per_cpu_percent(self):
+        last = psutil.cpu_percent(interval=0.001, percpu=True)
+        self.assertEqual(len(last), psutil.cpu_count())
+        for x in range(100):
+            new = psutil.cpu_percent(interval=None, percpu=True)
+            for percent in new:
+                self._test_cpu_percent(percent, last, new)
+            last = new
+        with self.assertRaises(ValueError):
+            psutil.cpu_percent(interval=-1, percpu=True)
+
+    def test_cpu_times_percent(self):
+        last = psutil.cpu_times_percent(interval=0.001)
+        for x in range(100):
+            new = psutil.cpu_times_percent(interval=None)
+            for percent in new:
+                self._test_cpu_percent(percent, last, new)
+            self._test_cpu_percent(sum(new), last, new)
+            last = new
+
+    def test_per_cpu_times_percent(self):
+        last = psutil.cpu_times_percent(interval=0.001, percpu=True)
+        self.assertEqual(len(last), psutil.cpu_count())
+        for x in range(100):
+            new = psutil.cpu_times_percent(interval=None, percpu=True)
+            for cpu in new:
+                for percent in cpu:
+                    self._test_cpu_percent(percent, last, new)
+                self._test_cpu_percent(sum(cpu), last, new)
+            last = new
+
+    def test_per_cpu_times_percent_negative(self):
+        # see: https://github.com/giampaolo/psutil/issues/645
+        psutil.cpu_times_percent(percpu=True)
+        zero_times = [x._make([0 for x in range(len(x._fields))])
+                      for x in psutil.cpu_times(percpu=True)]
+        with mock.patch('psutil.cpu_times', return_value=zero_times):
+            for cpu in psutil.cpu_times_percent(percpu=True):
+                for percent in cpu:
+                    self._test_cpu_percent(percent, None, None)
+
+    def test_disk_usage(self):
+        usage = psutil.disk_usage(os.getcwd())
+        self.assertEqual(usage._fields, ('total', 'used', 'free', 'percent'))
+
+        assert usage.total > 0, usage
+        assert usage.used > 0, usage
+        assert usage.free > 0, usage
+        assert usage.total > usage.used, usage
+        assert usage.total > usage.free, usage
+        assert 0 <= usage.percent <= 100, usage.percent
+        if hasattr(shutil, 'disk_usage'):
+            # py >= 3.3, see: http://bugs.python.org/issue12442
+            shutil_usage = shutil.disk_usage(os.getcwd())
+            tolerance = 5 * 1024 * 1024  # 5MB
+            self.assertEqual(usage.total, shutil_usage.total)
+            self.assertAlmostEqual(usage.free, shutil_usage.free,
+                                   delta=tolerance)
+            self.assertAlmostEqual(usage.used, shutil_usage.used,
+                                   delta=tolerance)
+
+        # if path does not exist OSError ENOENT is expected across
+        # all platforms
+        fname = tempfile.mktemp()
+        with self.assertRaises(OSError) as exc:
+            psutil.disk_usage(fname)
+        self.assertEqual(exc.exception.errno, errno.ENOENT)
+
+    def test_disk_usage_unicode(self):
+        # See: https://github.com/giampaolo/psutil/issues/416
+        if ASCII_FS:
+            with self.assertRaises(UnicodeEncodeError):
+                psutil.disk_usage(TESTFN_UNICODE)
+
+    def test_disk_usage_bytes(self):
+        psutil.disk_usage(b'.')
+
+    def test_disk_partitions(self):
+        # all = False
+        ls = psutil.disk_partitions(all=False)
+        # on travis we get:
+        #     self.assertEqual(p.cpu_affinity(), [n])
+        # AssertionError: Lists differ: [0, 1, 2, 3, 4, 5, 6, 7,... != [0]
+        self.assertTrue(ls, msg=ls)
+        for disk in ls:
+            self.assertIsInstance(disk.device, str)
+            self.assertIsInstance(disk.mountpoint, str)
+            self.assertIsInstance(disk.fstype, str)
+            self.assertIsInstance(disk.opts, str)
+            if WINDOWS and 'cdrom' in disk.opts:
+                continue
+            if not POSIX:
+                assert os.path.exists(disk.device), disk
+            else:
+                # we cannot make any assumption about this, see:
+                # http://goo.gl/p9c43
+                disk.device
+            if SUNOS or TRAVIS:
+                # on solaris apparently mount points can also be files
+                assert os.path.exists(disk.mountpoint), disk
+            else:
+                assert os.path.isdir(disk.mountpoint), disk
+            assert disk.fstype, disk
+
+        # all = True
+        ls = psutil.disk_partitions(all=True)
+        self.assertTrue(ls, msg=ls)
+        for disk in psutil.disk_partitions(all=True):
+            if not WINDOWS:
+                try:
+                    os.stat(disk.mountpoint)
+                except OSError as err:
+                    if TRAVIS and OSX and err.errno == errno.EIO:
+                        continue
+                    # http://mail.python.org/pipermail/python-dev/
+                    #     2012-June/120787.html
+                    if err.errno not in (errno.EPERM, errno.EACCES):
+                        raise
+                else:
+                    if SUNOS or TRAVIS:
+                        # on solaris apparently mount points can also be files
+                        assert os.path.exists(disk.mountpoint), disk
+                    else:
+                        assert os.path.isdir(disk.mountpoint), disk
+            self.assertIsInstance(disk.fstype, str)
+            self.assertIsInstance(disk.opts, str)
+
+        def find_mount_point(path):
+            path = os.path.abspath(path)
+            while not os.path.ismount(path):
+                path = os.path.dirname(path)
+            return path.lower()
+
+        mount = find_mount_point(__file__)
+        mounts = [x.mountpoint.lower() for x in
+                  psutil.disk_partitions(all=True)]
+        self.assertIn(mount, mounts)
+        psutil.disk_usage(mount)
+
+    def test_net_io_counters(self):
+        def check_ntuple(nt):
+            self.assertEqual(nt[0], nt.bytes_sent)
+            self.assertEqual(nt[1], nt.bytes_recv)
+            self.assertEqual(nt[2], nt.packets_sent)
+            self.assertEqual(nt[3], nt.packets_recv)
+            self.assertEqual(nt[4], nt.errin)
+            self.assertEqual(nt[5], nt.errout)
+            self.assertEqual(nt[6], nt.dropin)
+            self.assertEqual(nt[7], nt.dropout)
+            assert nt.bytes_sent >= 0, nt
+            assert nt.bytes_recv >= 0, nt
+            assert nt.packets_sent >= 0, nt
+            assert nt.packets_recv >= 0, nt
+            assert nt.errin >= 0, nt
+            assert nt.errout >= 0, nt
+            assert nt.dropin >= 0, nt
+            assert nt.dropout >= 0, nt
+
+        ret = psutil.net_io_counters(pernic=False)
+        check_ntuple(ret)
+        ret = psutil.net_io_counters(pernic=True)
+        self.assertNotEqual(ret, [])
+        for key in ret:
+            self.assertTrue(key)
+            self.assertIsInstance(key, str)
+            check_ntuple(ret[key])
+
+    def test_net_io_counters_no_nics(self):
+        # Emulate a case where no NICs are installed, see:
+        # https://github.com/giampaolo/psutil/issues/1062
+        with mock.patch('psutil._psplatform.net_io_counters',
+                        return_value={}) as m:
+            self.assertIsNone(psutil.net_io_counters(pernic=False))
+            self.assertEqual(psutil.net_io_counters(pernic=True), {})
+            assert m.called
+
+    def test_net_if_addrs(self):
+        nics = psutil.net_if_addrs()
+        assert nics, nics
+
+        nic_stats = psutil.net_if_stats()
+
+        # Not reliable on all platforms (net_if_addrs() reports more
+        # interfaces).
+        # self.assertEqual(sorted(nics.keys()),
+        #                  sorted(psutil.net_io_counters(pernic=True).keys()))
+
+        families = set([socket.AF_INET, socket.AF_INET6, psutil.AF_LINK])
+        for nic, addrs in nics.items():
+            self.assertIsInstance(nic, str)
+            self.assertEqual(len(set(addrs)), len(addrs))
+            for addr in addrs:
+                self.assertIsInstance(addr.family, int)
+                self.assertIsInstance(addr.address, str)
+                self.assertIsInstance(addr.netmask, (str, type(None)))
+                self.assertIsInstance(addr.broadcast, (str, type(None)))
+                self.assertIn(addr.family, families)
+                if sys.version_info >= (3, 4):
+                    self.assertIsInstance(addr.family, enum.IntEnum)
+                if nic_stats[nic].isup:
+                    # Do not test binding to addresses of interfaces
+                    # that are down
+                    if addr.family == socket.AF_INET:
+                        s = socket.socket(addr.family)
+                        with contextlib.closing(s):
+                            s.bind((addr.address, 0))
+                    elif addr.family == socket.AF_INET6:
+                        info = socket.getaddrinfo(
+                            addr.address, 0, socket.AF_INET6,
+                            socket.SOCK_STREAM, 0, socket.AI_PASSIVE)[0]
+                        af, socktype, proto, canonname, sa = info
+                        s = socket.socket(af, socktype, proto)
+                        with contextlib.closing(s):
+                            s.bind(sa)
+                for ip in (addr.address, addr.netmask, addr.broadcast,
+                           addr.ptp):
+                    if ip is not None:
+                        # TODO: skip AF_INET6 for now because I get:
+                        # AddressValueError: Only hex digits permitted in
+                        # u'c6f3%lxcbr0' in u'fe80::c8e0:fff:fe54:c6f3%lxcbr0'
+                        if addr.family != socket.AF_INET6:
+                            check_net_address(ip, addr.family)
+                # broadcast and ptp addresses are mutually exclusive
+                if addr.broadcast:
+                    self.assertIsNone(addr.ptp)
+                elif addr.ptp:
+                    self.assertIsNone(addr.broadcast)
+
+        if BSD or OSX or SUNOS:
+            if hasattr(socket, "AF_LINK"):
+                self.assertEqual(psutil.AF_LINK, socket.AF_LINK)
+        elif LINUX:
+            self.assertEqual(psutil.AF_LINK, socket.AF_PACKET)
+        elif WINDOWS:
+            self.assertEqual(psutil.AF_LINK, -1)
+
+    def test_net_if_addrs_mac_null_bytes(self):
+        # Simulate that the underlying C function returns an incomplete
+        # MAC address. psutil is supposed to fill it with null bytes.
+        # https://github.com/giampaolo/psutil/issues/786
+        if POSIX:
+            ret = [('em1', psutil.AF_LINK, '06:3d:29', None, None, None)]
+        else:
+            ret = [('em1', -1, '06-3d-29', None, None, None)]
+        with mock.patch('psutil._psplatform.net_if_addrs',
+                        return_value=ret) as m:
+            addr = psutil.net_if_addrs()['em1'][0]
+            assert m.called
+            if POSIX:
+                self.assertEqual(addr.address, '06:3d:29:00:00:00')
+            else:
+                self.assertEqual(addr.address, '06-3d-29-00-00-00')
+
+    @unittest.skipIf(TRAVIS, "unreliable on TRAVIS")  # raises EPERM
+    def test_net_if_stats(self):
+        nics = psutil.net_if_stats()
+        assert nics, nics
+        all_duplexes = (psutil.NIC_DUPLEX_FULL,
+                        psutil.NIC_DUPLEX_HALF,
+                        psutil.NIC_DUPLEX_UNKNOWN)
+        for name, stats in nics.items():
+            self.assertIsInstance(name, str)
+            isup, duplex, speed, mtu = stats
+            self.assertIsInstance(isup, bool)
+            self.assertIn(duplex, all_duplexes)
+            self.assertIn(duplex, all_duplexes)
+            self.assertGreaterEqual(speed, 0)
+            self.assertGreaterEqual(mtu, 0)
+
+    @unittest.skipIf(LINUX and not os.path.exists('/proc/diskstats'),
+                     '/proc/diskstats not available on this linux version')
+    @unittest.skipIf(APPVEYOR and psutil.disk_io_counters() is None,
+                     "unreliable on APPVEYOR")  # no visible disks
+    def test_disk_io_counters(self):
+        def check_ntuple(nt):
+            self.assertEqual(nt[0], nt.read_count)
+            self.assertEqual(nt[1], nt.write_count)
+            self.assertEqual(nt[2], nt.read_bytes)
+            self.assertEqual(nt[3], nt.write_bytes)
+            if not (OPENBSD or NETBSD):
+                self.assertEqual(nt[4], nt.read_time)
+                self.assertEqual(nt[5], nt.write_time)
+                if LINUX:
+                    self.assertEqual(nt[6], nt.read_merged_count)
+                    self.assertEqual(nt[7], nt.write_merged_count)
+                    self.assertEqual(nt[8], nt.busy_time)
+                elif FREEBSD:
+                    self.assertEqual(nt[6], nt.busy_time)
+            for name in nt._fields:
+                assert getattr(nt, name) >= 0, nt
+
+        ret = psutil.disk_io_counters(perdisk=False)
+        assert ret is not None, "no disks on this system?"
+        check_ntuple(ret)
+        ret = psutil.disk_io_counters(perdisk=True)
+        # make sure there are no duplicates
+        self.assertEqual(len(ret), len(set(ret)))
+        for key in ret:
+            assert key, key
+            check_ntuple(ret[key])
+            if LINUX and key[-1].isdigit():
+                # if 'sda1' is listed 'sda' shouldn't, see:
+                # https://github.com/giampaolo/psutil/issues/338
+                while key[-1].isdigit():
+                    key = key[:-1]
+                self.assertNotIn(key, ret.keys())
+
+    def test_disk_io_counters_no_disks(self):
+        # Emulate a case where no disks are installed, see:
+        # https://github.com/giampaolo/psutil/issues/1062
+        with mock.patch('psutil._psplatform.disk_io_counters',
+                        return_value={}) as m:
+            self.assertIsNone(psutil.disk_io_counters(perdisk=False))
+            self.assertEqual(psutil.disk_io_counters(perdisk=True), {})
+            assert m.called
+
+    # can't find users on APPVEYOR or TRAVIS
+    @unittest.skipIf(APPVEYOR or TRAVIS and not psutil.users(),
+                     "unreliable on APPVEYOR or TRAVIS")
+    def test_users(self):
+        users = psutil.users()
+        self.assertNotEqual(users, [])
+        for user in users:
+            assert user.name, user
+            self.assertIsInstance(user.name, str)
+            self.assertIsInstance(user.terminal, (str, type(None)))
+            if user.host is not None:
+                self.assertIsInstance(user.host, (str, type(None)))
+            user.terminal
+            user.host
+            assert user.started > 0.0, user
+            datetime.datetime.fromtimestamp(user.started)
+            if WINDOWS or OPENBSD:
+                self.assertIsNone(user.pid)
+            else:
+                psutil.Process(user.pid)
+
+    def test_cpu_stats(self):
+        # Tested more extensively in per-platform test modules.
+        infos = psutil.cpu_stats()
+        self.assertEqual(
+            infos._fields,
+            ('ctx_switches', 'interrupts', 'soft_interrupts', 'syscalls'))
+        for name in infos._fields:
+            value = getattr(infos, name)
+            self.assertGreaterEqual(value, 0)
+            # on AIX, ctx_switches is always 0
+            if not AIX and name in ('ctx_switches', 'interrupts'):
+                self.assertGreater(value, 0)
+
+    @unittest.skipIf(not HAS_CPU_FREQ, "not suported")
+    def test_cpu_freq(self):
+        def check_ls(ls):
+            for nt in ls:
+                self.assertEqual(nt._fields, ('current', 'min', 'max'))
+                self.assertLessEqual(nt.current, nt.max)
+                for name in nt._fields:
+                    value = getattr(nt, name)
+                    self.assertIsInstance(value, (int, long, float))
+                    self.assertGreaterEqual(value, 0)
+
+        ls = psutil.cpu_freq(percpu=True)
+        if TRAVIS and not ls:
+            return
+
+        assert ls, ls
+        check_ls([psutil.cpu_freq(percpu=False)])
+
+        if LINUX:
+            self.assertEqual(len(ls), psutil.cpu_count())
+
+    def test_os_constants(self):
+        names = ["POSIX", "WINDOWS", "LINUX", "OSX", "FREEBSD", "OPENBSD",
+                 "NETBSD", "BSD", "SUNOS"]
+        for name in names:
+            self.assertIsInstance(getattr(psutil, name), bool, msg=name)
+
+        if os.name == 'posix':
+            assert psutil.POSIX
+            assert not psutil.WINDOWS
+            names.remove("POSIX")
+            if "linux" in sys.platform.lower():
+                assert psutil.LINUX
+                names.remove("LINUX")
+            elif "bsd" in sys.platform.lower():
+                assert psutil.BSD
+                self.assertEqual([psutil.FREEBSD, psutil.OPENBSD,
+                                  psutil.NETBSD].count(True), 1)
+                names.remove("BSD")
+                names.remove("FREEBSD")
+                names.remove("OPENBSD")
+                names.remove("NETBSD")
+            elif "sunos" in sys.platform.lower() or \
+                    "solaris" in sys.platform.lower():
+                assert psutil.SUNOS
+                names.remove("SUNOS")
+            elif "darwin" in sys.platform.lower():
+                assert psutil.OSX
+                names.remove("OSX")
+        else:
+            assert psutil.WINDOWS
+            assert not psutil.POSIX
+            names.remove("WINDOWS")
+
+        # assert all other constants are set to False
+        for name in names:
+            self.assertIs(getattr(psutil, name), False, msg=name)
+
+    @unittest.skipIf(not HAS_SENSORS_TEMPERATURES, "not supported")
+    def test_sensors_temperatures(self):
+        temps = psutil.sensors_temperatures()
+        for name, entries in temps.items():
+            self.assertIsInstance(name, str)
+            for entry in entries:
+                self.assertIsInstance(entry.label, str)
+                if entry.current is not None:
+                    self.assertGreaterEqual(entry.current, 0)
+                if entry.high is not None:
+                    self.assertGreaterEqual(entry.high, 0)
+                if entry.critical is not None:
+                    self.assertGreaterEqual(entry.critical, 0)
+
+    @unittest.skipIf(not HAS_SENSORS_TEMPERATURES, "not supported")
+    def test_sensors_temperatures_fahreneit(self):
+        d = {'coretemp': [('label', 50.0, 60.0, 70.0)]}
+        with mock.patch("psutil._psplatform.sensors_temperatures",
+                        return_value=d) as m:
+            temps = psutil.sensors_temperatures(
+                fahrenheit=True)['coretemp'][0]
+            assert m.called
+            self.assertEqual(temps.current, 122.0)
+            self.assertEqual(temps.high, 140.0)
+            self.assertEqual(temps.critical, 158.0)
+
+    @unittest.skipIf(not HAS_SENSORS_BATTERY, "not supported")
+    @unittest.skipIf(not HAS_BATTERY, "no battery")
+    def test_sensors_battery(self):
+        ret = psutil.sensors_battery()
+        self.assertGreaterEqual(ret.percent, 0)
+        self.assertLessEqual(ret.percent, 100)
+        if ret.secsleft not in (psutil.POWER_TIME_UNKNOWN,
+                                psutil.POWER_TIME_UNLIMITED):
+            self.assertGreaterEqual(ret.secsleft, 0)
+        else:
+            if ret.secsleft == psutil.POWER_TIME_UNLIMITED:
+                self.assertTrue(ret.power_plugged)
+        self.assertIsInstance(ret.power_plugged, bool)
+
+    @unittest.skipIf(not HAS_SENSORS_FANS, "not supported")
+    def test_sensors_fans(self):
+        fans = psutil.sensors_fans()
+        for name, entries in fans.items():
+            self.assertIsInstance(name, str)
+            for entry in entries:
+                self.assertIsInstance(entry.label, str)
+                self.assertIsInstance(entry.current, (int, long))
+                self.assertGreaterEqual(entry.current, 0)
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_unicode.py b/psutil/tests/test_unicode.py
new file mode 100755
index 00000000..6383c9be
--- /dev/null
+++ b/psutil/tests/test_unicode.py
@@ -0,0 +1,366 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Notes about unicode handling in psutil
+======================================
+
+In psutil these are the APIs returning or dealing with a string
+('not tested' means they are not tested to deal with non-ASCII strings):
+
+* Process.cmdline()
+* Process.connections('unix')
+* Process.cwd()
+* Process.environ()
+* Process.exe()
+* Process.memory_maps()
+* Process.name()
+* Process.open_files()
+* Process.username()             (not tested)
+
+* disk_io_counters()             (not tested)
+* disk_partitions()              (not tested)
+* disk_usage(str)
+* net_connections('unix')
+* net_if_addrs()                 (not tested)
+* net_if_stats()                 (not tested)
+* net_io_counters()              (not tested)
+* sensors_fans()                 (not tested)
+* sensors_temperatures()         (not tested)
+* users()                        (not tested)
+
+* WindowsService.binpath()       (not tested)
+* WindowsService.description()   (not tested)
+* WindowsService.display_name()  (not tested)
+* WindowsService.name()          (not tested)
+* WindowsService.status()        (not tested)
+* WindowsService.username()      (not tested)
+
+In here we create a unicode path with a funky non-ASCII name and (where
+possible) make psutil return it back (e.g. on name(), exe(), open_files(),
+etc.) and make sure that:
+
+* psutil never crashes with UnicodeDecodeError
+* the returned path matches
+
+For a detailed explanation of how psutil handles unicode see:
+- https://github.com/giampaolo/psutil/issues/1040
+- http://psutil.readthedocs.io/#unicode
+"""
+
+import os
+import traceback
+import warnings
+from contextlib import closing
+
+from psutil import BSD
+from psutil import OPENBSD
+from psutil import OSX
+from psutil import POSIX
+from psutil import WINDOWS
+from psutil._compat import PY3
+from psutil._compat import u
+from psutil.tests import APPVEYOR
+from psutil.tests import ASCII_FS
+from psutil.tests import bind_unix_socket
+from psutil.tests import chdir
+from psutil.tests import copyload_shared_lib
+from psutil.tests import create_exe
+from psutil.tests import get_test_subprocess
+from psutil.tests import HAS_CONNECTIONS_UNIX
+from psutil.tests import HAS_ENVIRON
+from psutil.tests import HAS_MEMORY_MAPS
+from psutil.tests import mock
+from psutil.tests import reap_children
+from psutil.tests import run_test_module_by_name
+from psutil.tests import safe_mkdir
+from psutil.tests import safe_rmpath as _safe_rmpath
+from psutil.tests import skip_on_access_denied
+from psutil.tests import TESTFILE_PREFIX
+from psutil.tests import TESTFN
+from psutil.tests import TESTFN_UNICODE
+from psutil.tests import TRAVIS
+from psutil.tests import unittest
+from psutil.tests import unix_socket_path
+import psutil
+
+
+def safe_rmpath(path):
+    if APPVEYOR:
+        # TODO - this is quite random and I'm not sure why it happens,
+        # nor I can reproduce it locally:
+        # https://ci.appveyor.com/project/giampaolo/psutil/build/job/
+        #     jiq2cgd6stsbtn60
+        # safe_rmpath() happens after reap_children() so this is weird
+        # Perhaps wait_procs() on Windows is broken? Maybe because
+        # of STILL_ACTIVE?
+        # https://github.com/giampaolo/psutil/blob/
+        #     68c7a70728a31d8b8b58f4be6c4c0baa2f449eda/psutil/arch/
+        #     windows/process_info.c#L146
+        try:
+            return _safe_rmpath(path)
+        except WindowsError:
+            traceback.print_exc()
+    else:
+        return _safe_rmpath(path)
+
+
+def subprocess_supports_unicode(name):
+    """Return True if both the fs and the subprocess module can
+    deal with a unicode file name.
+    """
+    if PY3:
+        return True
+    try:
+        safe_rmpath(name)
+        create_exe(name)
+        get_test_subprocess(cmd=[name])
+    except UnicodeEncodeError:
+        return False
+    else:
+        return True
+    finally:
+        reap_children()
+
+
+# An invalid unicode string.
+if PY3:
+    INVALID_NAME = (TESTFN.encode('utf8') + b"f\xc0\x80").decode(
+        'utf8', 'surrogateescape')
+else:
+    INVALID_NAME = TESTFN + "f\xc0\x80"
+
+
+# ===================================================================
+# FS APIs
+# ===================================================================
+
+
+class _BaseFSAPIsTests(object):
+    funky_name = None
+
+    @classmethod
+    def setUpClass(cls):
+        safe_rmpath(cls.funky_name)
+        create_exe(cls.funky_name)
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children()
+        safe_rmpath(cls.funky_name)
+
+    def tearDown(self):
+        reap_children()
+
+    def expect_exact_path_match(self):
+        raise NotImplementedError("must be implemented in subclass")
+
+    def test_proc_exe(self):
+        subp = get_test_subprocess(cmd=[self.funky_name])
+        p = psutil.Process(subp.pid)
+        exe = p.exe()
+        self.assertIsInstance(exe, str)
+        if self.expect_exact_path_match():
+            self.assertEqual(exe, self.funky_name)
+
+    def test_proc_name(self):
+        subp = get_test_subprocess(cmd=[self.funky_name])
+        if WINDOWS:
+            # On Windows name() is determined from exe() first, because
+            # it's faster; we want to overcome the internal optimization
+            # and test name() instead of exe().
+            with mock.patch("psutil._psplatform.cext.proc_exe",
+                            side_effect=psutil.AccessDenied(os.getpid())) as m:
+                name = psutil.Process(subp.pid).name()
+                assert m.called
+        else:
+            name = psutil.Process(subp.pid).name()
+        self.assertIsInstance(name, str)
+        if self.expect_exact_path_match():
+            self.assertEqual(name, os.path.basename(self.funky_name))
+
+    def test_proc_cmdline(self):
+        subp = get_test_subprocess(cmd=[self.funky_name])
+        p = psutil.Process(subp.pid)
+        cmdline = p.cmdline()
+        for part in cmdline:
+            self.assertIsInstance(part, str)
+        if self.expect_exact_path_match():
+            self.assertEqual(cmdline, [self.funky_name])
+
+    def test_proc_cwd(self):
+        dname = self.funky_name + "2"
+        self.addCleanup(safe_rmpath, dname)
+        safe_mkdir(dname)
+        with chdir(dname):
+            p = psutil.Process()
+            cwd = p.cwd()
+        self.assertIsInstance(p.cwd(), str)
+        if self.expect_exact_path_match():
+            self.assertEqual(cwd, dname)
+
+    def test_proc_open_files(self):
+        p = psutil.Process()
+        start = set(p.open_files())
+        with open(self.funky_name, 'rb'):
+            new = set(p.open_files())
+        path = (new - start).pop().path
+        self.assertIsInstance(path, str)
+        if BSD and not path:
+            # XXX - see https://github.com/giampaolo/psutil/issues/595
+            return self.skipTest("open_files on BSD is broken")
+        if self.expect_exact_path_match():
+            self.assertEqual(os.path.normcase(path),
+                             os.path.normcase(self.funky_name))
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    def test_proc_connections(self):
+        suffix = os.path.basename(self.funky_name)
+        with unix_socket_path(suffix=suffix) as name:
+            try:
+                sock = bind_unix_socket(name)
+            except UnicodeEncodeError:
+                if PY3:
+                    raise
+                else:
+                    raise unittest.SkipTest("not supported")
+            with closing(sock):
+                conn = psutil.Process().connections('unix')[0]
+                self.assertIsInstance(conn.laddr, str)
+                # AF_UNIX addr not set on OpenBSD
+                if not OPENBSD:
+                    self.assertEqual(conn.laddr, name)
+
+    @unittest.skipIf(not POSIX, "POSIX only")
+    @unittest.skipIf(not HAS_CONNECTIONS_UNIX, "can't list UNIX sockets")
+    @skip_on_access_denied()
+    def test_net_connections(self):
+        def find_sock(cons):
+            for conn in cons:
+                if os.path.basename(conn.laddr).startswith(TESTFILE_PREFIX):
+                    return conn
+            raise ValueError("connection not found")
+
+        suffix = os.path.basename(self.funky_name)
+        with unix_socket_path(suffix=suffix) as name:
+            try:
+                sock = bind_unix_socket(name)
+            except UnicodeEncodeError:
+                if PY3:
+                    raise
+                else:
+                    raise unittest.SkipTest("not supported")
+            with closing(sock):
+                cons = psutil.net_connections(kind='unix')
+                # AF_UNIX addr not set on OpenBSD
+                if not OPENBSD:
+                    conn = find_sock(cons)
+                    self.assertIsInstance(conn.laddr, str)
+                    self.assertEqual(conn.laddr, name)
+
+    def test_disk_usage(self):
+        dname = self.funky_name + "2"
+        self.addCleanup(safe_rmpath, dname)
+        safe_mkdir(dname)
+        psutil.disk_usage(dname)
+
+    @unittest.skipIf(not HAS_MEMORY_MAPS, "not supported")
+    @unittest.skipIf(not PY3, "ctypes does not support unicode on PY2")
+    def test_memory_maps(self):
+        # XXX: on Python 2, using ctypes.CDLL with a unicode path
+        # opens a message box which blocks the test run.
+        with copyload_shared_lib(dst_prefix=self.funky_name) as funky_path:
+            def normpath(p):
+                return os.path.realpath(os.path.normcase(p))
+            libpaths = [normpath(x.path)
+                        for x in psutil.Process().memory_maps()]
+            # ...just to have a clearer msg in case of failure
+            libpaths = [x for x in libpaths if TESTFILE_PREFIX in x]
+            self.assertIn(normpath(funky_path), libpaths)
+            for path in libpaths:
+                self.assertIsInstance(path, str)
+
+
+@unittest.skipIf(OSX and TRAVIS, "unreliable on TRAVIS")  # TODO
+@unittest.skipIf(ASCII_FS, "ASCII fs")
+@unittest.skipIf(not subprocess_supports_unicode(TESTFN_UNICODE),
+                 "subprocess can't deal with unicode")
+class TestFSAPIs(_BaseFSAPIsTests, unittest.TestCase):
+    """Test FS APIs with a funky, valid, UTF8 path name."""
+    funky_name = TESTFN_UNICODE
+
+    @classmethod
+    def expect_exact_path_match(cls):
+        # Do not expect psutil to correctly handle unicode paths on
+        # Python 2 if os.listdir() is not able either.
+        if PY3:
+            return True
+        else:
+            here = '.' if isinstance(cls.funky_name, str) else u('.')
+            with warnings.catch_warnings():
+                warnings.simplefilter("ignore")
+                return cls.funky_name in os.listdir(here)
+
+
+@unittest.skipIf(OSX and TRAVIS, "unreliable on TRAVIS")  # TODO
+@unittest.skipIf(not subprocess_supports_unicode(INVALID_NAME),
+                 "subprocess can't deal with invalid unicode")
+class TestFSAPIsWithInvalidPath(_BaseFSAPIsTests, unittest.TestCase):
+    """Test FS APIs with a funky, invalid path name."""
+    funky_name = INVALID_NAME
+
+    @classmethod
+    def expect_exact_path_match(cls):
+        # Invalid unicode names are supposed to work on Python 2.
+        return True
+
+
+@unittest.skipIf(not WINDOWS, "WINDOWS only")
+class TestWinProcessName(unittest.TestCase):
+
+    def test_name_type(self):
+        # On Windows name() is determined from exe() first, because
+        # it's faster; we want to overcome the internal optimization
+        # and test name() instead of exe().
+        with mock.patch("psutil._psplatform.cext.proc_exe",
+                        side_effect=psutil.AccessDenied(os.getpid())) as m:
+            self.assertIsInstance(psutil.Process().name(), str)
+            assert m.called
+
+
+# ===================================================================
+# Non fs APIs
+# ===================================================================
+
+
+class TestNonFSAPIS(unittest.TestCase):
+    """Unicode tests for non fs-related APIs."""
+
+    def tearDown(self):
+        reap_children()
+
+    @unittest.skipIf(not HAS_ENVIRON, "not supported")
+    def test_proc_environ(self):
+        # Note: differently from others, this test does not deal
+        # with fs paths. On Python 2 subprocess module is broken as
+        # it's not able to handle with non-ASCII env vars, so
+        # we use "è", which is part of the extended ASCII table
+        # (unicode point <= 255).
+        env = os.environ.copy()
+        funky_str = TESTFN_UNICODE if PY3 else 'è'
+        env['FUNNY_ARG'] = funky_str
+        sproc = get_test_subprocess(env=env)
+        p = psutil.Process(sproc.pid)
+        env = p.environ()
+        for k, v in env.items():
+            self.assertIsInstance(k, str)
+            self.assertIsInstance(v, str)
+        self.assertEqual(env['FUNNY_ARG'], funky_str)
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)
diff --git a/psutil/tests/test_windows.py b/psutil/tests/test_windows.py
new file mode 100755
index 00000000..32c46f67
--- /dev/null
+++ b/psutil/tests/test_windows.py
@@ -0,0 +1,837 @@
+#!/usr/bin/env python
+# -*- coding: UTF-8 -*
+
+# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Windows specific tests."""
+
+import datetime
+import errno
+import glob
+import os
+import platform
+import re
+import signal
+import subprocess
+import sys
+import time
+import warnings
+
+import psutil
+from psutil import WINDOWS
+from psutil.tests import APPVEYOR
+from psutil.tests import get_test_subprocess
+from psutil.tests import HAS_BATTERY
+from psutil.tests import mock
+from psutil.tests import reap_children
+from psutil.tests import retry_before_failing
+from psutil.tests import run_test_module_by_name
+from psutil.tests import sh
+from psutil.tests import unittest
+
+with warnings.catch_warnings():
+    warnings.simplefilter("ignore")
+    try:
+        import win32api  # requires "pip install pypiwin32"
+        import win32con
+        import win32process
+        import wmi  # requires "pip install wmi" / "make setup-dev-env"
+    except ImportError:
+        if os.name == 'nt':
+            raise
+
+
+cext = psutil._psplatform.cext
+
+# are we a 64 bit process
+IS_64_BIT = sys.maxsize > 2**32
+
+
+def wrap_exceptions(fun):
+    def wrapper(self, *args, **kwargs):
+        try:
+            return fun(self, *args, **kwargs)
+        except OSError as err:
+            from psutil._pswindows import ACCESS_DENIED_SET
+            if err.errno in ACCESS_DENIED_SET:
+                raise psutil.AccessDenied(None, None)
+            if err.errno == errno.ESRCH:
+                raise psutil.NoSuchProcess(None, None)
+            raise
+    return wrapper
+
+
+# ===================================================================
+# System APIs
+# ===================================================================
+
+
+@unittest.skipIf(not WINDOWS, "WINDOWS only")
+class TestSystemAPIs(unittest.TestCase):
+
+    def test_nic_names(self):
+        out = sh('ipconfig /all')
+        nics = psutil.net_io_counters(pernic=True).keys()
+        for nic in nics:
+            if "pseudo-interface" in nic.replace(' ', '-').lower():
+                continue
+            if nic not in out:
+                self.fail(
+                    "%r nic wasn't found in 'ipconfig /all' output" % nic)
+
+    @unittest.skipIf('NUMBER_OF_PROCESSORS' not in os.environ,
+                     'NUMBER_OF_PROCESSORS env var is not available')
+    def test_cpu_count(self):
+        num_cpus = int(os.environ['NUMBER_OF_PROCESSORS'])
+        self.assertEqual(num_cpus, psutil.cpu_count())
+
+    def test_cpu_count_2(self):
+        sys_value = win32api.GetSystemInfo()[5]
+        psutil_value = psutil.cpu_count()
+        self.assertEqual(sys_value, psutil_value)
+
+    def test_cpu_freq(self):
+        w = wmi.WMI()
+        proc = w.Win32_Processor()[0]
+        self.assertEqual(proc.CurrentClockSpeed, psutil.cpu_freq().current)
+        self.assertEqual(proc.MaxClockSpeed, psutil.cpu_freq().max)
+
+    def test_total_phymem(self):
+        w = wmi.WMI().Win32_ComputerSystem()[0]
+        self.assertEqual(int(w.TotalPhysicalMemory),
+                         psutil.virtual_memory().total)
+
+    # @unittest.skipIf(wmi is None, "wmi module is not installed")
+    # def test__UPTIME(self):
+    #     # _UPTIME constant is not public but it is used internally
+    #     # as value to return for pid 0 creation time.
+    #     # WMI behaves the same.
+    #     w = wmi.WMI().Win32_Process(ProcessId=self.pid)[0]
+    #     p = psutil.Process(0)
+    #     wmic_create = str(w.CreationDate.split('.')[0])
+    #     psutil_create = time.strftime("%Y%m%d%H%M%S",
+    #                                   time.localtime(p.create_time()))
+
+    # Note: this test is not very reliable
+    @unittest.skipIf(APPVEYOR, "test not relieable on appveyor")
+    @retry_before_failing()
+    def test_pids(self):
+        # Note: this test might fail if the OS is starting/killing
+        # other processes in the meantime
+        w = wmi.WMI().Win32_Process()
+        wmi_pids = set([x.ProcessId for x in w])
+        psutil_pids = set(psutil.pids())
+        self.assertEqual(wmi_pids, psutil_pids)
+
+    @retry_before_failing()
+    def test_disks(self):
+        ps_parts = psutil.disk_partitions(all=True)
+        wmi_parts = wmi.WMI().Win32_LogicalDisk()
+        for ps_part in ps_parts:
+            for wmi_part in wmi_parts:
+                if ps_part.device.replace('\\', '') == wmi_part.DeviceID:
+                    if not ps_part.mountpoint:
+                        # this is usually a CD-ROM with no disk inserted
+                        break
+                    try:
+                        usage = psutil.disk_usage(ps_part.mountpoint)
+                    except OSError as err:
+                        if err.errno == errno.ENOENT:
+                            # usually this is the floppy
+                            break
+                        else:
+                            raise
+                    self.assertEqual(usage.total, int(wmi_part.Size))
+                    wmi_free = int(wmi_part.FreeSpace)
+                    self.assertEqual(usage.free, wmi_free)
+                    # 10 MB tollerance
+                    if abs(usage.free - wmi_free) > 10 * 1024 * 1024:
+                        self.fail("psutil=%s, wmi=%s" % (
+                            usage.free, wmi_free))
+                    break
+            else:
+                self.fail("can't find partition %s" % repr(ps_part))
+
+    def test_disk_usage(self):
+        for disk in psutil.disk_partitions():
+            sys_value = win32api.GetDiskFreeSpaceEx(disk.mountpoint)
+            psutil_value = psutil.disk_usage(disk.mountpoint)
+            self.assertAlmostEqual(sys_value[0], psutil_value.free,
+                                   delta=1024 * 1024)
+            self.assertAlmostEqual(sys_value[1], psutil_value.total,
+                                   delta=1024 * 1024)
+            self.assertEqual(psutil_value.used,
+                             psutil_value.total - psutil_value.free)
+
+    def test_disk_partitions(self):
+        sys_value = [
+            x + '\\' for x in win32api.GetLogicalDriveStrings().split("\\\x00")
+            if x and not x.startswith('A:')]
+        psutil_value = [x.mountpoint for x in psutil.disk_partitions(all=True)]
+        self.assertEqual(sys_value, psutil_value)
+
+    def test_net_if_stats(self):
+        ps_names = set(cext.net_if_stats())
+        wmi_adapters = wmi.WMI().Win32_NetworkAdapter()
+        wmi_names = set()
+        for wmi_adapter in wmi_adapters:
+            wmi_names.add(wmi_adapter.Name)
+            wmi_names.add(wmi_adapter.NetConnectionID)
+        self.assertTrue(ps_names & wmi_names,
+                        "no common entries in %s, %s" % (ps_names, wmi_names))
+
+    def test_boot_time(self):
+        wmi_os = wmi.WMI().Win32_OperatingSystem()
+        wmi_btime_str = wmi_os[0].LastBootUpTime.split('.')[0]
+        wmi_btime_dt = datetime.datetime.strptime(
+            wmi_btime_str, "%Y%m%d%H%M%S")
+        psutil_dt = datetime.datetime.fromtimestamp(psutil.boot_time())
+        diff = abs((wmi_btime_dt - psutil_dt).total_seconds())
+        # Wmic time is 2-3 secs lower for some reason; that's OK.
+        self.assertLessEqual(diff, 3)
+
+    def test_boot_time_fluctuation(self):
+        # https://github.com/giampaolo/psutil/issues/1007
+        with mock.patch('psutil._pswindows.cext.boot_time', return_value=5):
+            self.assertEqual(psutil.boot_time(), 5)
+        with mock.patch('psutil._pswindows.cext.boot_time', return_value=4):
+            self.assertEqual(psutil.boot_time(), 5)
+        with mock.patch('psutil._pswindows.cext.boot_time', return_value=6):
+            self.assertEqual(psutil.boot_time(), 5)
+        with mock.patch('psutil._pswindows.cext.boot_time', return_value=333):
+            self.assertEqual(psutil.boot_time(), 333)
+
+
+# ===================================================================
+# sensors_battery()
+# ===================================================================
+
+
+@unittest.skipIf(not WINDOWS, "WINDOWS only")
+class TestSensorsBattery(unittest.TestCase):
+
+    def test_has_battery(self):
+        if win32api.GetPwrCapabilities()['SystemBatteriesPresent']:
+            self.assertIsNotNone(psutil.sensors_battery())
+        else:
+            self.assertIsNone(psutil.sensors_battery())
+
+    @unittest.skipIf(not HAS_BATTERY, "no battery")
+    def test_percent(self):
+        w = wmi.WMI()
+        battery_wmi = w.query('select * from Win32_Battery')[0]
+        battery_psutil = psutil.sensors_battery()
+        self.assertAlmostEqual(
+            battery_psutil.percent, battery_wmi.EstimatedChargeRemaining,
+            delta=1)
+
+    @unittest.skipIf(not HAS_BATTERY, "no battery")
+    def test_power_plugged(self):
+        w = wmi.WMI()
+        battery_wmi = w.query('select * from Win32_Battery')[0]
+        battery_psutil = psutil.sensors_battery()
+        # Status codes:
+        # https://msdn.microsoft.com/en-us/library/aa394074(v=vs.85).aspx
+        self.assertEqual(battery_psutil.power_plugged,
+                         battery_wmi.BatteryStatus == 2)
+
+    def test_emulate_no_battery(self):
+        with mock.patch("psutil._pswindows.cext.sensors_battery",
+                        return_value=(0, 128, 0, 0)) as m:
+            self.assertIsNone(psutil.sensors_battery())
+            assert m.called
+
+    def test_emulate_power_connected(self):
+        with mock.patch("psutil._pswindows.cext.sensors_battery",
+                        return_value=(1, 0, 0, 0)) as m:
+            self.assertEqual(psutil.sensors_battery().secsleft,
+                             psutil.POWER_TIME_UNLIMITED)
+            assert m.called
+
+    def test_emulate_power_charging(self):
+        with mock.patch("psutil._pswindows.cext.sensors_battery",
+                        return_value=(0, 8, 0, 0)) as m:
+            self.assertEqual(psutil.sensors_battery().secsleft,
+                             psutil.POWER_TIME_UNLIMITED)
+            assert m.called
+
+    def test_emulate_secs_left_unknown(self):
+        with mock.patch("psutil._pswindows.cext.sensors_battery",
+                        return_value=(0, 0, 0, -1)) as m:
+            self.assertEqual(psutil.sensors_battery().secsleft,
+                             psutil.POWER_TIME_UNKNOWN)
+            assert m.called
+
+
+# ===================================================================
+# Process APIs
+# ===================================================================
+
+
+@unittest.skipIf(not WINDOWS, "WINDOWS only")
+class TestProcess(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        cls.pid = get_test_subprocess().pid
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children()
+
+    def test_issue_24(self):
+        p = psutil.Process(0)
+        self.assertRaises(psutil.AccessDenied, p.kill)
+
+    def test_special_pid(self):
+        p = psutil.Process(4)
+        self.assertEqual(p.name(), 'System')
+        # use __str__ to access all common Process properties to check
+        # that nothing strange happens
+        str(p)
+        p.username()
+        self.assertTrue(p.create_time() >= 0.0)
+        try:
+            rss, vms = p.memory_info()[:2]
+        except psutil.AccessDenied:
+            # expected on Windows Vista and Windows 7
+            if not platform.uname()[1] in ('vista', 'win-7', 'win7'):
+                raise
+        else:
+            self.assertTrue(rss > 0)
+
+    def test_send_signal(self):
+        p = psutil.Process(self.pid)
+        self.assertRaises(ValueError, p.send_signal, signal.SIGINT)
+
+    def test_exe(self):
+        for p in psutil.process_iter():
+            try:
+                self.assertEqual(os.path.basename(p.exe()), p.name())
+            except psutil.Error:
+                pass
+
+    def test_num_handles_increment(self):
+        p = psutil.Process(os.getpid())
+        before = p.num_handles()
+        handle = win32api.OpenProcess(win32con.PROCESS_QUERY_INFORMATION,
+                                      win32con.FALSE, os.getpid())
+        after = p.num_handles()
+        self.assertEqual(after, before + 1)
+        win32api.CloseHandle(handle)
+        self.assertEqual(p.num_handles(), before)
+
+    def test_handles_leak(self):
+        # Call all Process methods and make sure no handles are left
+        # open. This is here mainly to make sure functions using
+        # OpenProcess() always call CloseHandle().
+        def call(p, attr):
+            attr = getattr(p, name, None)
+            if attr is not None and callable(attr):
+                attr()
+            else:
+                attr
+
+        p = psutil.Process(self.pid)
+        failures = []
+        for name in dir(psutil.Process):
+            if name.startswith('_') \
+                    or name in ('terminate', 'kill', 'suspend', 'resume',
+                                'nice', 'send_signal', 'wait', 'children',
+                                'as_dict', 'memory_info_ex'):
+                continue
+            else:
+                try:
+                    call(p, name)
+                    num1 = p.num_handles()
+                    call(p, name)
+                    num2 = p.num_handles()
+                except (psutil.NoSuchProcess, psutil.AccessDenied):
+                    pass
+                else:
+                    if num2 > num1:
+                        fail = \
+                            "failure while processing Process.%s method " \
+                            "(before=%s, after=%s)" % (name, num1, num2)
+                        failures.append(fail)
+        if failures:
+            self.fail('\n' + '\n'.join(failures))
+
+    def test_name_always_available(self):
+        # On Windows name() is never supposed to raise AccessDenied,
+        # see https://github.com/giampaolo/psutil/issues/627
+        for p in psutil.process_iter():
+            try:
+                p.name()
+            except psutil.NoSuchProcess:
+                pass
+
+    @unittest.skipIf(not sys.version_info >= (2, 7),
+                     "CTRL_* signals not supported")
+    def test_ctrl_signals(self):
+        p = psutil.Process(get_test_subprocess().pid)
+        p.send_signal(signal.CTRL_C_EVENT)
+        p.send_signal(signal.CTRL_BREAK_EVENT)
+        p.kill()
+        p.wait()
+        self.assertRaises(psutil.NoSuchProcess,
+                          p.send_signal, signal.CTRL_C_EVENT)
+        self.assertRaises(psutil.NoSuchProcess,
+                          p.send_signal, signal.CTRL_BREAK_EVENT)
+
+    def test_compare_name_exe(self):
+        for p in psutil.process_iter():
+            try:
+                a = os.path.basename(p.exe())
+                b = p.name()
+            except (psutil.NoSuchProcess, psutil.AccessDenied):
+                pass
+            else:
+                self.assertEqual(a, b)
+
+    def test_username(self):
+        self.assertEqual(psutil.Process().username(),
+                         win32api.GetUserNameEx(win32con.NameSamCompatible))
+
+    def test_cmdline(self):
+        sys_value = re.sub(' +', ' ', win32api.GetCommandLine()).strip()
+        psutil_value = ' '.join(psutil.Process().cmdline())
+        self.assertEqual(sys_value, psutil_value)
+
+    # XXX - occasional failures
+
+    # def test_cpu_times(self):
+    #     handle = win32api.OpenProcess(win32con.PROCESS_QUERY_INFORMATION,
+    #                                   win32con.FALSE, os.getpid())
+    #     self.addCleanup(win32api.CloseHandle, handle)
+    #     sys_value = win32process.GetProcessTimes(handle)
+    #     psutil_value = psutil.Process().cpu_times()
+    #     self.assertAlmostEqual(
+    #         psutil_value.user, sys_value['UserTime'] / 10000000.0,
+    #         delta=0.2)
+    #     self.assertAlmostEqual(
+    #         psutil_value.user, sys_value['KernelTime'] / 10000000.0,
+    #         delta=0.2)
+
+    def test_nice(self):
+        handle = win32api.OpenProcess(win32con.PROCESS_QUERY_INFORMATION,
+                                      win32con.FALSE, os.getpid())
+        self.addCleanup(win32api.CloseHandle, handle)
+        sys_value = win32process.GetPriorityClass(handle)
+        psutil_value = psutil.Process().nice()
+        self.assertEqual(psutil_value, sys_value)
+
+    def test_memory_info(self):
+        handle = win32api.OpenProcess(win32con.PROCESS_QUERY_INFORMATION,
+                                      win32con.FALSE, self.pid)
+        self.addCleanup(win32api.CloseHandle, handle)
+        sys_value = win32process.GetProcessMemoryInfo(handle)
+        psutil_value = psutil.Process(self.pid).memory_info()
+        self.assertEqual(
+            sys_value['PeakWorkingSetSize'], psutil_value.peak_wset)
+        self.assertEqual(
+            sys_value['WorkingSetSize'], psutil_value.wset)
+        self.assertEqual(
+            sys_value['QuotaPeakPagedPoolUsage'], psutil_value.peak_paged_pool)
+        self.assertEqual(
+            sys_value['QuotaPagedPoolUsage'], psutil_value.paged_pool)
+        self.assertEqual(
+            sys_value['QuotaPeakNonPagedPoolUsage'],
+            psutil_value.peak_nonpaged_pool)
+        self.assertEqual(
+            sys_value['QuotaNonPagedPoolUsage'], psutil_value.nonpaged_pool)
+        self.assertEqual(
+            sys_value['PagefileUsage'], psutil_value.pagefile)
+        self.assertEqual(
+            sys_value['PeakPagefileUsage'], psutil_value.peak_pagefile)
+
+        self.assertEqual(psutil_value.rss, psutil_value.wset)
+        self.assertEqual(psutil_value.vms, psutil_value.pagefile)
+
+    def test_wait(self):
+        handle = win32api.OpenProcess(win32con.PROCESS_QUERY_INFORMATION,
+                                      win32con.FALSE, self.pid)
+        self.addCleanup(win32api.CloseHandle, handle)
+        p = psutil.Process(self.pid)
+        p.terminate()
+        psutil_value = p.wait()
+        sys_value = win32process.GetExitCodeProcess(handle)
+        self.assertEqual(psutil_value, sys_value)
+
+    def test_cpu_affinity(self):
+        def from_bitmask(x):
+            return [i for i in range(64) if (1 << i) & x]
+
+        handle = win32api.OpenProcess(win32con.PROCESS_QUERY_INFORMATION,
+                                      win32con.FALSE, self.pid)
+        self.addCleanup(win32api.CloseHandle, handle)
+        sys_value = from_bitmask(
+            win32process.GetProcessAffinityMask(handle)[0])
+        psutil_value = psutil.Process(self.pid).cpu_affinity()
+        self.assertEqual(psutil_value, sys_value)
+
+    def test_io_counters(self):
+        handle = win32api.OpenProcess(win32con.PROCESS_QUERY_INFORMATION,
+                                      win32con.FALSE, os.getpid())
+        self.addCleanup(win32api.CloseHandle, handle)
+        sys_value = win32process.GetProcessIoCounters(handle)
+        psutil_value = psutil.Process().io_counters()
+        self.assertEqual(
+            psutil_value.read_count, sys_value['ReadOperationCount'])
+        self.assertEqual(
+            psutil_value.write_count, sys_value['WriteOperationCount'])
+        self.assertEqual(
+            psutil_value.read_bytes, sys_value['ReadTransferCount'])
+        self.assertEqual(
+            psutil_value.write_bytes, sys_value['WriteTransferCount'])
+        self.assertEqual(
+            psutil_value.other_count, sys_value['OtherOperationCount'])
+        self.assertEqual(
+            psutil_value.other_bytes, sys_value['OtherTransferCount'])
+
+    def test_num_handles(self):
+        import ctypes
+        import ctypes.wintypes
+        PROCESS_QUERY_INFORMATION = 0x400
+        handle = ctypes.windll.kernel32.OpenProcess(
+            PROCESS_QUERY_INFORMATION, 0, os.getpid())
+        self.addCleanup(ctypes.windll.kernel32.CloseHandle, handle)
+        hndcnt = ctypes.wintypes.DWORD()
+        ctypes.windll.kernel32.GetProcessHandleCount(
+            handle, ctypes.byref(hndcnt))
+        sys_value = hndcnt.value
+        psutil_value = psutil.Process().num_handles()
+        ctypes.windll.kernel32.CloseHandle(handle)
+        self.assertEqual(psutil_value, sys_value + 1)
+
+
+@unittest.skipIf(not WINDOWS, "WINDOWS only")
+class TestProcessWMI(unittest.TestCase):
+    """Compare Process API results with WMI."""
+
+    @classmethod
+    def setUpClass(cls):
+        cls.pid = get_test_subprocess().pid
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children()
+
+    def test_name(self):
+        w = wmi.WMI().Win32_Process(ProcessId=self.pid)[0]
+        p = psutil.Process(self.pid)
+        self.assertEqual(p.name(), w.Caption)
+
+    def test_exe(self):
+        w = wmi.WMI().Win32_Process(ProcessId=self.pid)[0]
+        p = psutil.Process(self.pid)
+        # Note: wmi reports the exe as a lower case string.
+        # Being Windows paths case-insensitive we ignore that.
+        self.assertEqual(p.exe().lower(), w.ExecutablePath.lower())
+
+    def test_cmdline(self):
+        w = wmi.WMI().Win32_Process(ProcessId=self.pid)[0]
+        p = psutil.Process(self.pid)
+        self.assertEqual(' '.join(p.cmdline()),
+                         w.CommandLine.replace('"', ''))
+
+    def test_username(self):
+        w = wmi.WMI().Win32_Process(ProcessId=self.pid)[0]
+        p = psutil.Process(self.pid)
+        domain, _, username = w.GetOwner()
+        username = "%s\\%s" % (domain, username)
+        self.assertEqual(p.username(), username)
+
+    def test_memory_rss(self):
+        time.sleep(0.1)
+        w = wmi.WMI().Win32_Process(ProcessId=self.pid)[0]
+        p = psutil.Process(self.pid)
+        rss = p.memory_info().rss
+        self.assertEqual(rss, int(w.WorkingSetSize))
+
+    def test_memory_vms(self):
+        time.sleep(0.1)
+        w = wmi.WMI().Win32_Process(ProcessId=self.pid)[0]
+        p = psutil.Process(self.pid)
+        vms = p.memory_info().vms
+        # http://msdn.microsoft.com/en-us/library/aa394372(VS.85).aspx
+        # ...claims that PageFileUsage is represented in Kilo
+        # bytes but funnily enough on certain platforms bytes are
+        # returned instead.
+        wmi_usage = int(w.PageFileUsage)
+        if (vms != wmi_usage) and (vms != wmi_usage * 1024):
+            self.fail("wmi=%s, psutil=%s" % (wmi_usage, vms))
+
+    def test_create_time(self):
+        w = wmi.WMI().Win32_Process(ProcessId=self.pid)[0]
+        p = psutil.Process(self.pid)
+        wmic_create = str(w.CreationDate.split('.')[0])
+        psutil_create = time.strftime("%Y%m%d%H%M%S",
+                                      time.localtime(p.create_time()))
+        self.assertEqual(wmic_create, psutil_create)
+
+
+@unittest.skipIf(not WINDOWS, "WINDOWS only")
+class TestDualProcessImplementation(unittest.TestCase):
+    """
+    Certain APIs on Windows have 2 internal implementations, one
+    based on documented Windows APIs, another one based
+    NtQuerySystemInformation() which gets called as fallback in
+    case the first fails because of limited permission error.
+    Here we test that the two methods return the exact same value,
+    see:
+    https://github.com/giampaolo/psutil/issues/304
+    """
+
+    @classmethod
+    def setUpClass(cls):
+        cls.pid = get_test_subprocess().pid
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children()
+    # ---
+    # same tests as above but mimicks the AccessDenied failure of
+    # the first (fast) method failing with AD.
+
+    def test_name(self):
+        name = psutil.Process(self.pid).name()
+        with mock.patch("psutil._psplatform.cext.proc_exe",
+                        side_effect=psutil.AccessDenied(os.getpid())) as fun:
+            self.assertEqual(psutil.Process(self.pid).name(), name)
+            assert fun.called
+
+    def test_memory_info(self):
+        mem_1 = psutil.Process(self.pid).memory_info()
+        with mock.patch("psutil._psplatform.cext.proc_memory_info",
+                        side_effect=OSError(errno.EPERM, "msg")) as fun:
+            mem_2 = psutil.Process(self.pid).memory_info()
+            self.assertEqual(len(mem_1), len(mem_2))
+            for i in range(len(mem_1)):
+                self.assertGreaterEqual(mem_1[i], 0)
+                self.assertGreaterEqual(mem_2[i], 0)
+                self.assertAlmostEqual(mem_1[i], mem_2[i], delta=512)
+            assert fun.called
+
+    def test_create_time(self):
+        ctime = psutil.Process(self.pid).create_time()
+        with mock.patch("psutil._psplatform.cext.proc_create_time",
+                        side_effect=OSError(errno.EPERM, "msg")) as fun:
+            self.assertEqual(psutil.Process(self.pid).create_time(), ctime)
+            assert fun.called
+
+    def test_cpu_times(self):
+        cpu_times_1 = psutil.Process(self.pid).cpu_times()
+        with mock.patch("psutil._psplatform.cext.proc_cpu_times",
+                        side_effect=OSError(errno.EPERM, "msg")) as fun:
+            cpu_times_2 = psutil.Process(self.pid).cpu_times()
+            assert fun.called
+            self.assertAlmostEqual(
+                cpu_times_1.user, cpu_times_2.user, delta=0.01)
+            self.assertAlmostEqual(
+                cpu_times_1.system, cpu_times_2.system, delta=0.01)
+
+    def test_io_counters(self):
+        io_counters_1 = psutil.Process(self.pid).io_counters()
+        with mock.patch("psutil._psplatform.cext.proc_io_counters",
+                        side_effect=OSError(errno.EPERM, "msg")) as fun:
+            io_counters_2 = psutil.Process(self.pid).io_counters()
+            for i in range(len(io_counters_1)):
+                self.assertAlmostEqual(
+                    io_counters_1[i], io_counters_2[i], delta=5)
+            assert fun.called
+
+    def test_num_handles(self):
+        num_handles = psutil.Process(self.pid).num_handles()
+        with mock.patch("psutil._psplatform.cext.proc_num_handles",
+                        side_effect=OSError(errno.EPERM, "msg")) as fun:
+            self.assertEqual(psutil.Process(self.pid).num_handles(),
+                             num_handles)
+            assert fun.called
+
+
+@unittest.skipIf(not WINDOWS, "WINDOWS only")
+class RemoteProcessTestCase(unittest.TestCase):
+    """Certain functions require calling ReadProcessMemory.
+    This trivially works when called on the current process.
+    Check that this works on other processes, especially when they
+    have a different bitness.
+    """
+
+    @staticmethod
+    def find_other_interpreter():
+        # find a python interpreter that is of the opposite bitness from us
+        code = "import sys; sys.stdout.write(str(sys.maxsize > 2**32))"
+
+        # XXX: a different and probably more stable approach might be to access
+        # the registry but accessing 64 bit paths from a 32 bit process
+        for filename in glob.glob(r"C:\Python*\python.exe"):
+            proc = subprocess.Popen(args=[filename, "-c", code],
+                                    stdout=subprocess.PIPE,
+                                    stderr=subprocess.STDOUT)
+            output, _ = proc.communicate()
+            if output == str(not IS_64_BIT):
+                return filename
+
+    @classmethod
+    def setUpClass(cls):
+        other_python = cls.find_other_interpreter()
+
+        if other_python is None:
+            raise unittest.SkipTest(
+                "could not find interpreter with opposite bitness")
+
+        if IS_64_BIT:
+            cls.python64 = sys.executable
+            cls.python32 = other_python
+        else:
+            cls.python64 = other_python
+            cls.python32 = sys.executable
+
+    test_args = ["-c", "import sys; sys.stdin.read()"]
+
+    def setUp(self):
+        env = os.environ.copy()
+        env["THINK_OF_A_NUMBER"] = str(os.getpid())
+        self.proc32 = get_test_subprocess([self.python32] + self.test_args,
+                                          env=env,
+                                          stdin=subprocess.PIPE)
+        self.proc64 = get_test_subprocess([self.python64] + self.test_args,
+                                          env=env,
+                                          stdin=subprocess.PIPE)
+
+    def tearDown(self):
+        self.proc32.communicate()
+        self.proc64.communicate()
+        reap_children()
+
+    @classmethod
+    def tearDownClass(cls):
+        reap_children()
+
+    def test_cmdline_32(self):
+        p = psutil.Process(self.proc32.pid)
+        self.assertEqual(len(p.cmdline()), 3)
+        self.assertEqual(p.cmdline()[1:], self.test_args)
+
+    def test_cmdline_64(self):
+        p = psutil.Process(self.proc64.pid)
+        self.assertEqual(len(p.cmdline()), 3)
+        self.assertEqual(p.cmdline()[1:], self.test_args)
+
+    def test_cwd_32(self):
+        p = psutil.Process(self.proc32.pid)
+        self.assertEqual(p.cwd(), os.getcwd())
+
+    def test_cwd_64(self):
+        p = psutil.Process(self.proc64.pid)
+        self.assertEqual(p.cwd(), os.getcwd())
+
+    def test_environ_32(self):
+        p = psutil.Process(self.proc32.pid)
+        e = p.environ()
+        self.assertIn("THINK_OF_A_NUMBER", e)
+        self.assertEquals(e["THINK_OF_A_NUMBER"], str(os.getpid()))
+
+    def test_environ_64(self):
+        p = psutil.Process(self.proc64.pid)
+        e = p.environ()
+        self.assertIn("THINK_OF_A_NUMBER", e)
+        self.assertEquals(e["THINK_OF_A_NUMBER"], str(os.getpid()))
+
+
+# ===================================================================
+# Windows services
+# ===================================================================
+
+
+@unittest.skipIf(not WINDOWS, "WINDOWS only")
+class TestServices(unittest.TestCase):
+
+    def test_win_service_iter(self):
+        valid_statuses = set([
+            "running",
+            "paused",
+            "start",
+            "pause",
+            "continue",
+            "stop",
+            "stopped",
+        ])
+        valid_start_types = set([
+            "automatic",
+            "manual",
+            "disabled",
+        ])
+        valid_statuses = set([
+            "running",
+            "paused",
+            "start_pending",
+            "pause_pending",
+            "continue_pending",
+            "stop_pending",
+            "stopped"
+        ])
+        for serv in psutil.win_service_iter():
+            data = serv.as_dict()
+            self.assertIsInstance(data['name'], str)
+            self.assertNotEqual(data['name'].strip(), "")
+            self.assertIsInstance(data['display_name'], str)
+            self.assertIsInstance(data['username'], str)
+            self.assertIn(data['status'], valid_statuses)
+            if data['pid'] is not None:
+                psutil.Process(data['pid'])
+            self.assertIsInstance(data['binpath'], str)
+            self.assertIsInstance(data['username'], str)
+            self.assertIsInstance(data['start_type'], str)
+            self.assertIn(data['start_type'], valid_start_types)
+            self.assertIn(data['status'], valid_statuses)
+            self.assertIsInstance(data['description'], str)
+            pid = serv.pid()
+            if pid is not None:
+                p = psutil.Process(pid)
+                self.assertTrue(p.is_running())
+            # win_service_get
+            s = psutil.win_service_get(serv.name())
+            # test __eq__
+            self.assertEqual(serv, s)
+
+    def test_win_service_get(self):
+        name = next(psutil.win_service_iter()).name()
+
+        with self.assertRaises(psutil.NoSuchProcess) as cm:
+            psutil.win_service_get(name + '???')
+        self.assertEqual(cm.exception.name, name + '???')
+
+        # test NoSuchProcess
+        service = psutil.win_service_get(name)
+        exc = WindowsError(
+            psutil._psplatform.cext.ERROR_SERVICE_DOES_NOT_EXIST, "")
+        with mock.patch("psutil._psplatform.cext.winservice_query_status",
+                        side_effect=exc):
+            self.assertRaises(psutil.NoSuchProcess, service.status)
+        with mock.patch("psutil._psplatform.cext.winservice_query_config",
+                        side_effect=exc):
+            self.assertRaises(psutil.NoSuchProcess, service.username)
+
+        # test AccessDenied
+        exc = WindowsError(
+            psutil._psplatform.cext.ERROR_ACCESS_DENIED, "")
+        with mock.patch("psutil._psplatform.cext.winservice_query_status",
+                        side_effect=exc):
+            self.assertRaises(psutil.AccessDenied, service.status)
+        with mock.patch("psutil._psplatform.cext.winservice_query_config",
+                        side_effect=exc):
+            self.assertRaises(psutil.AccessDenied, service.username)
+
+        # test __str__ and __repr__
+        self.assertIn(service.name(), str(service))
+        self.assertIn(service.display_name(), str(service))
+        self.assertIn(service.name(), repr(service))
+        self.assertIn(service.display_name(), repr(service))
+
+
+if __name__ == '__main__':
+    run_test_module_by_name(__file__)