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diff --git a/Tools/Scripts/webkitpy/port/server_process.py b/Tools/Scripts/webkitpy/port/server_process.py
new file mode 100644
index 000000000..8184d2587
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+++ b/Tools/Scripts/webkitpy/port/server_process.py
@@ -0,0 +1,380 @@
+# Copyright (C) 2010 Google Inc. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the Google name nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Package that implements the ServerProcess wrapper class"""
+
+import errno
+import logging
+import signal
+import sys
+import time
+
+# Note that although win32 python does provide an implementation of
+# the win32 select API, it only works on sockets, and not on the named pipes
+# used by subprocess, so we have to use the native APIs directly.
+if sys.platform == 'win32':
+    import msvcrt
+    import win32pipe
+    import win32file
+else:
+    import fcntl
+    import os
+    import select
+
+from webkitpy.common.system.executive import ScriptError
+
+
+_log = logging.getLogger(__name__)
+
+
+class ServerProcess(object):
+    """This class provides a wrapper around a subprocess that
+    implements a simple request/response usage model. The primary benefit
+    is that reading responses takes a deadline, so that we don't ever block
+    indefinitely. The class also handles transparently restarting processes
+    as necessary to keep issuing commands."""
+
+    def __init__(self, port_obj, name, cmd, env=None, universal_newlines=False, treat_no_data_as_crash=False):
+        self._port = port_obj
+        self._name = name  # Should be the command name (e.g. DumpRenderTree, ImageDiff)
+        self._cmd = cmd
+        self._env = env
+        # Set if the process outputs non-standard newlines like '\r\n' or '\r'.
+        # Don't set if there will be binary data or the data must be ASCII encoded.
+        self._universal_newlines = universal_newlines
+        self._treat_no_data_as_crash = treat_no_data_as_crash
+        self._host = self._port.host
+        self._pid = None
+        self._reset()
+
+        # See comment in imports for why we need the win32 APIs and can't just use select.
+        # FIXME: there should be a way to get win32 vs. cygwin from platforminfo.
+        self._use_win32_apis = sys.platform == 'win32'
+
+    def name(self):
+        return self._name
+
+    def pid(self):
+        return self._pid
+
+    def _reset(self):
+        if getattr(self, '_proc', None):
+            if self._proc.stdin:
+                self._proc.stdin.close()
+                self._proc.stdin = None
+            if self._proc.stdout:
+                self._proc.stdout.close()
+                self._proc.stdout = None
+            if self._proc.stderr:
+                self._proc.stderr.close()
+                self._proc.stderr = None
+
+        self._proc = None
+        self._output = str()  # bytesarray() once we require Python 2.6
+        self._error = str()  # bytesarray() once we require Python 2.6
+        self._crashed = False
+        self.timed_out = False
+
+    def process_name(self):
+        return self._name
+
+    def _start(self):
+        if self._proc:
+            raise ValueError("%s already running" % self._name)
+        self._reset()
+        # close_fds is a workaround for http://bugs.python.org/issue2320
+        close_fds = not self._host.platform.is_win()
+        self._proc = self._host.executive.popen(self._cmd, stdin=self._host.executive.PIPE,
+            stdout=self._host.executive.PIPE,
+            stderr=self._host.executive.PIPE,
+            close_fds=close_fds,
+            env=self._env,
+            universal_newlines=self._universal_newlines)
+        self._pid = self._proc.pid
+        self._port.find_system_pid(self.name(), self._pid)
+        fd = self._proc.stdout.fileno()
+        if not self._use_win32_apis:
+            fl = fcntl.fcntl(fd, fcntl.F_GETFL)
+            fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
+            fd = self._proc.stderr.fileno()
+            fl = fcntl.fcntl(fd, fcntl.F_GETFL)
+            fcntl.fcntl(fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
+
+    def _handle_possible_interrupt(self):
+        """This routine checks to see if the process crashed or exited
+        because of a keyboard interrupt and raises KeyboardInterrupt
+        accordingly."""
+        # FIXME: Linux and Mac set the returncode to -signal.SIGINT if a
+        # subprocess is killed with a ctrl^C.  Previous comments in this
+        # routine said that supposedly Windows returns 0xc000001d, but that's not what
+        # -1073741510 evaluates to. Figure out what the right value is
+        # for win32 and cygwin here ...
+        if self._proc.returncode in (-1073741510, -signal.SIGINT):
+            raise KeyboardInterrupt
+
+    def poll(self):
+        """Check to see if the underlying process is running; returns None
+        if it still is (wrapper around subprocess.poll)."""
+        if self._proc:
+            return self._proc.poll()
+        return None
+
+    def write(self, bytes):
+        """Write a request to the subprocess. The subprocess is (re-)start()'ed
+        if is not already running."""
+        if not self._proc:
+            self._start()
+        try:
+            self._proc.stdin.write(bytes)
+        except IOError, e:
+            self.stop(0.0)
+            # stop() calls _reset(), so we have to set crashed to True after calling stop().
+            self._crashed = True
+
+    def _pop_stdout_line_if_ready(self):
+        index_after_newline = self._output.find('\n') + 1
+        if index_after_newline > 0:
+            return self._pop_output_bytes(index_after_newline)
+        return None
+
+    def _pop_stderr_line_if_ready(self):
+        index_after_newline = self._error.find('\n') + 1
+        if index_after_newline > 0:
+            return self._pop_error_bytes(index_after_newline)
+        return None
+
+    def pop_all_buffered_stderr(self):
+        return self._pop_error_bytes(len(self._error))
+
+    def read_stdout_line(self, deadline):
+        return self._read(deadline, self._pop_stdout_line_if_ready)
+
+    def read_stderr_line(self, deadline):
+        return self._read(deadline, self._pop_stderr_line_if_ready)
+
+    def read_either_stdout_or_stderr_line(self, deadline):
+        def retrieve_bytes_from_buffers():
+            stdout_line = self._pop_stdout_line_if_ready()
+            if stdout_line:
+                return stdout_line, None
+            stderr_line = self._pop_stderr_line_if_ready()
+            if stderr_line:
+                return None, stderr_line
+            return None  # Instructs the caller to keep waiting.
+
+        return_value = self._read(deadline, retrieve_bytes_from_buffers)
+        # FIXME: This is a bit of a hack around the fact that _read normally only returns one value, but this caller wants it to return two.
+        if return_value is None:
+            return None, None
+        return return_value
+
+    def read_stdout(self, deadline, size):
+        if size <= 0:
+            raise ValueError('ServerProcess.read() called with a non-positive size: %d ' % size)
+
+        def retrieve_bytes_from_stdout_buffer():
+            if len(self._output) >= size:
+                return self._pop_output_bytes(size)
+            return None
+
+        return self._read(deadline, retrieve_bytes_from_stdout_buffer)
+
+    def _log(self, message):
+        # This is a bit of a hack, but we first log a blank line to avoid
+        # messing up the master process's output.
+        _log.info('')
+        _log.info(message)
+
+    def _handle_timeout(self):
+        self.timed_out = True
+        self._port.sample_process(self._name, self._proc.pid)
+
+    def _split_string_after_index(self, string, index):
+        return string[:index], string[index:]
+
+    def _pop_output_bytes(self, bytes_count):
+        output, self._output = self._split_string_after_index(self._output, bytes_count)
+        return output
+
+    def _pop_error_bytes(self, bytes_count):
+        output, self._error = self._split_string_after_index(self._error, bytes_count)
+        return output
+
+    def _wait_for_data_and_update_buffers_using_select(self, deadline, stopping=False):
+        if self._proc.stdout.closed or self._proc.stderr.closed:
+            # If the process crashed and is using FIFOs, like Chromium Android, the
+            # stdout and stderr pipes will be closed.
+            return
+
+        out_fd = self._proc.stdout.fileno()
+        err_fd = self._proc.stderr.fileno()
+        select_fds = (out_fd, err_fd)
+        try:
+            read_fds, _, _ = select.select(select_fds, [], select_fds, max(deadline - time.time(), 0))
+        except select.error, e:
+            # We can ignore EINVAL since it's likely the process just crashed and we'll
+            # figure that out the next time through the loop in _read().
+            if e.args[0] == errno.EINVAL:
+                return
+            raise
+
+        try:
+            # Note that we may get no data during read() even though
+            # select says we got something; see the select() man page
+            # on linux. I don't know if this happens on Mac OS and
+            # other Unixen as well, but we don't bother special-casing
+            # Linux because it's relatively harmless either way.
+            if out_fd in read_fds:
+                data = self._proc.stdout.read()
+                if not data and not stopping and (self._treat_no_data_as_crash or self._proc.poll()):
+                    self._crashed = True
+                self._output += data
+
+            if err_fd in read_fds:
+                data = self._proc.stderr.read()
+                if not data and not stopping and (self._treat_no_data_as_crash or self._proc.poll()):
+                    self._crashed = True
+                self._error += data
+        except IOError, e:
+            # We can ignore the IOErrors because we will detect if the subporcess crashed
+            # the next time through the loop in _read()
+            pass
+
+    def _wait_for_data_and_update_buffers_using_win32_apis(self, deadline):
+        # See http://code.activestate.com/recipes/440554-module-to-allow-asynchronous-subprocess-use-on-win/
+        # and http://docs.activestate.com/activepython/2.6/pywin32/modules.html
+        # for documentation on all of these win32-specific modules.
+        now = time.time()
+        out_fh = msvcrt.get_osfhandle(self._proc.stdout.fileno())
+        err_fh = msvcrt.get_osfhandle(self._proc.stderr.fileno())
+        while (self._proc.poll() is None) and (now < deadline):
+            output = self._non_blocking_read_win32(out_fh)
+            error = self._non_blocking_read_win32(err_fh)
+            if output or error:
+                if output:
+                    self._output += output
+                if error:
+                    self._error += error
+                return
+            time.sleep(0.01)
+            now = time.time()
+        return
+
+    def _non_blocking_read_win32(self, handle):
+        try:
+            _, avail, _ = win32pipe.PeekNamedPipe(handle, 0)
+            if avail > 0:
+                _, buf = win32file.ReadFile(handle, avail, None)
+                return buf
+        except Exception, e:
+            if e[0] not in (109, errno.ESHUTDOWN):  # 109 == win32 ERROR_BROKEN_PIPE
+                raise
+        return None
+
+    def has_crashed(self):
+        if not self._crashed and self.poll():
+            self._crashed = True
+            self._handle_possible_interrupt()
+        return self._crashed
+
+    # This read function is a bit oddly-designed, as it polls both stdout and stderr, yet
+    # only reads/returns from one of them (buffering both in local self._output/self._error).
+    # It might be cleaner to pass in the file descriptor to poll instead.
+    def _read(self, deadline, fetch_bytes_from_buffers_callback):
+        while True:
+            if self.has_crashed():
+                return None
+
+            if time.time() > deadline:
+                self._handle_timeout()
+                return None
+
+            bytes = fetch_bytes_from_buffers_callback()
+            if bytes is not None:
+                return bytes
+
+            if self._use_win32_apis:
+                self._wait_for_data_and_update_buffers_using_win32_apis(deadline)
+            else:
+                self._wait_for_data_and_update_buffers_using_select(deadline)
+
+    def start(self):
+        if not self._proc:
+            self._start()
+
+    def stop(self, timeout_secs=3.0):
+        if not self._proc:
+            return (None, None)
+
+        # Only bother to check for leaks or stderr if the process is still running.
+        if self.poll() is None:
+            self._port.check_for_leaks(self.name(), self.pid())
+
+        now = time.time()
+        if self._proc.stdin:
+            self._proc.stdin.close()
+            self._proc.stdin = None
+        killed = False
+        if timeout_secs:
+            deadline = now + timeout_secs
+            while self._proc.poll() is None and time.time() < deadline:
+                time.sleep(0.01)
+            if self._proc.poll() is None:
+                _log.warning('stopping %s(pid %d) timed out, killing it' % (self._name, self._proc.pid))
+
+        if self._proc.poll() is None:
+            self._kill()
+            killed = True
+            _log.debug('killed pid %d' % self._proc.pid)
+
+        # read any remaining data on the pipes and return it.
+        if not killed:
+            if self._use_win32_apis:
+                self._wait_for_data_and_update_buffers_using_win32_apis(now)
+            else:
+                self._wait_for_data_and_update_buffers_using_select(now, stopping=True)
+        out, err = self._output, self._error
+        self._reset()
+        return (out, err)
+
+    def kill(self):
+        self.stop(0.0)
+
+    def _kill(self):
+        self._host.executive.kill_process(self._proc.pid)
+        if self._proc.poll() is not None:
+            self._proc.wait()
+
+    def replace_outputs(self, stdout, stderr):
+        assert self._proc
+        if stdout:
+            self._proc.stdout.close()
+            self._proc.stdout = stdout
+        if stderr:
+            self._proc.stderr.close()
+            self._proc.stderr = stderr