Add new utility function, reap_children(), to test_support. This should

be called at the end of each test that spawns children (perhaps it
should be called from regrtest instead?).  This will hopefully prevent
some of the unexplained failures in the buildbots (hppa and alpha)
during tests that spawn children.  The problems were not reproducible.
There were many zombies that remained at the end of several tests.
In the worst case, this shouldn't cause any more problems,
though it may not help either.  Time will tell.

14 files changed, 58 insertions, 8 deletions

diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index 504a6d771e..79acc07899 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -352,6 +352,7 @@ def test_main():
         BZ2DecompressorTest,
         FuncTest
     )
+    test_support.reap_children()
 
 if __name__ == '__main__':
     test_main()
diff --git a/Lib/test/test_cmd_line.py b/Lib/test/test_cmd_line.py
index ec860d1ef0..5e898634d9 100644
--- a/Lib/test/test_cmd_line.py
+++ b/Lib/test/test_cmd_line.py
@@ -87,6 +87,7 @@ class CmdLineTest(unittest.TestCase):
 
 def test_main():
     test.test_support.run_unittest(CmdLineTest)
+    test.test_support.reap_children()
 
 if __name__ == "__main__":
     test_main()
diff --git a/Lib/test/test_commands.py b/Lib/test/test_commands.py
index 0f7d15f184..b72a1b9b6a 100644
--- a/Lib/test/test_commands.py
+++ b/Lib/test/test_commands.py
@@ -5,7 +5,7 @@
 import unittest
 import os, tempfile, re
 
-from test.test_support import TestSkipped, run_unittest
+from test.test_support import TestSkipped, run_unittest, reap_children
 from commands import *
 
 # The module says:
@@ -58,6 +58,7 @@ class CommandTests(unittest.TestCase):
 
 def test_main():
     run_unittest(CommandTests)
+    reap_children()
 
 
 if __name__ == "__main__":
diff --git a/Lib/test/test_fork1.py b/Lib/test/test_fork1.py
index cba5fc7d19..e909844e91 100644
--- a/Lib/test/test_fork1.py
+++ b/Lib/test/test_fork1.py
@@ -3,7 +3,7 @@
 
 import os
 from test.fork_wait import ForkWait
-from test.test_support import TestSkipped, run_unittest
+from test.test_support import TestSkipped, run_unittest, reap_children
 
 try:
     os.fork
@@ -18,6 +18,7 @@ class ForkTest(ForkWait):
 
 def test_main():
     run_unittest(ForkTest)
+    reap_children()
 
 if __name__ == "__main__":
     test_main()
diff --git a/Lib/test/test_mailbox.py b/Lib/test/test_mailbox.py
index 474354f545..2f8cb8d55f 100644
--- a/Lib/test/test_mailbox.py
+++ b/Lib/test/test_mailbox.py
@@ -1785,6 +1785,7 @@ def test_main():
              TestMessageConversion, TestProxyFile, TestPartialFile,
              MaildirTestCase)
     test_support.run_unittest(*tests)
+    test_support.reap_children()
 
 
 if __name__ == '__main__':
diff --git a/Lib/test/test_popen.py b/Lib/test/test_popen.py
index 2b687ad31e..fbf5e054eb 100644
--- a/Lib/test/test_popen.py
+++ b/Lib/test/test_popen.py
@@ -6,7 +6,7 @@
 
 import os
 import sys
-from test.test_support import TestSkipped
+from test.test_support import TestSkipped, reap_children
 from os import popen
 
 # Test that command-lines get down as we expect.
@@ -35,5 +35,6 @@ def _test_commandline():
 def main():
     print "Test popen:"
     _test_commandline()
+    reap_children()
 
 main()
diff --git a/Lib/test/test_popen2.py b/Lib/test/test_popen2.py
index 4db3cd1f55..2d54eb008d 100644
--- a/Lib/test/test_popen2.py
+++ b/Lib/test/test_popen2.py
@@ -5,7 +5,7 @@
 
 import os
 import sys
-from test.test_support import TestSkipped
+from test.test_support import TestSkipped, reap_children
 
 # popen2 contains its own testing routine
 # which is especially useful to see if open files
@@ -75,3 +75,4 @@ def _test():
 
 main()
 _test()
+reap_children()
diff --git a/Lib/test/test_select.py b/Lib/test/test_select.py
index eaec52be19..d341324094 100644
--- a/Lib/test/test_select.py
+++ b/Lib/test/test_select.py
@@ -1,5 +1,5 @@
 # Testing select module
-from test.test_support import verbose
+from test.test_support import verbose, reap_children
 import select
 import os
 
@@ -65,5 +65,6 @@ def test():
             continue
         print 'Unexpected return values from select():', rfd, wfd, xfd
     p.close()
+    reap_children()
 
 test()
diff --git a/Lib/test/test_socketserver.py b/Lib/test/test_socketserver.py
index 93165470f9..dd4532fa4e 100644
--- a/Lib/test/test_socketserver.py
+++ b/Lib/test/test_socketserver.py
@@ -1,7 +1,8 @@
 # Test suite for SocketServer.py
 
 from test import test_support
-from test.test_support import verbose, verify, TESTFN, TestSkipped
+from test.test_support import (verbose, verify, TESTFN, TestSkipped,
+                               reap_children)
 test_support.requires('network')
 
 from SocketServer import *
@@ -199,6 +200,7 @@ def test_main():
         testall()
     finally:
         cleanup()
+    reap_children()
 
 if __name__ == "__main__":
     test_main()
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 9877f51783..b4e6c00d2e 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -27,6 +27,16 @@ def remove_stderr_debug_decorations(stderr):
     return re.sub(r"\[\d+ refs\]\r?\n?$", "", stderr)
 
 class ProcessTestCase(unittest.TestCase):
+    def setUp(self):
+	# Try to minimize the number of children we have so this test
+	# doesn't crash on some buildbots (Alphas in particular).
+        test_support.reap_children()
+
+    def tearDown(self):
+	# Try to minimize the number of children we have so this test
+	# doesn't crash on some buildbots (Alphas in particular).
+        test_support.reap_children()
+
     def mkstemp(self):
         """wrapper for mkstemp, calling mktemp if mkstemp is not available"""
         if hasattr(tempfile, "mkstemp"):
@@ -600,6 +610,7 @@ class ProcessTestCase(unittest.TestCase):
 
 def test_main():
     test_support.run_unittest(ProcessTestCase)
+    test_support.reap_children()
 
 if __name__ == "__main__":
     test_main()
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index 8e315496ee..6532c79a99 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -475,3 +475,24 @@ def threading_cleanup(num_active, num_limbo):
     while len(threading._limbo) != num_limbo and count < _MAX_COUNT:
         count += 1
         time.sleep(0.1)
+
+def reap_children():
+    """Use this function at the end of test_main() whenever sub-processes
+    are started.  This will help ensure that no extra children (zombies)
+    stick around to hog resources and create problems when looking
+    for refleaks.
+    """
+
+    # Reap all our dead child processes so we don't leave zombies around.
+    # These hog resources and might be causing some of the buildbots to die.
+    import os
+    if hasattr(os, 'waitpid'):
+        any_process = -1
+        while True:
+            try:
+                # This will raise an exception on Windows.  That's ok.
+                pid, status = os.waitpid(any_process, os.WNOHANG)
+                if pid == 0:
+                    break
+            except:
+                break
diff --git a/Lib/test/test_wait3.py b/Lib/test/test_wait3.py
index f6a41a698c..82799732fe 100644
--- a/Lib/test/test_wait3.py
+++ b/Lib/test/test_wait3.py
@@ -3,7 +3,7 @@
 
 import os
 from test.fork_wait import ForkWait
-from test.test_support import TestSkipped, run_unittest
+from test.test_support import TestSkipped, run_unittest, reap_children
 
 try:
     os.fork
@@ -27,6 +27,7 @@ class Wait3Test(ForkWait):
 
 def test_main():
     run_unittest(Wait3Test)
+    reap_children()
 
 if __name__ == "__main__":
     test_main()
diff --git a/Lib/test/test_wait4.py b/Lib/test/test_wait4.py
index 027e5c3524..711fd2dc38 100644
--- a/Lib/test/test_wait4.py
+++ b/Lib/test/test_wait4.py
@@ -3,7 +3,7 @@
 
 import os
 from test.fork_wait import ForkWait
-from test.test_support import TestSkipped, run_unittest
+from test.test_support import TestSkipped, run_unittest, reap_children
 
 try:
     os.fork
@@ -24,6 +24,7 @@ class Wait4Test(ForkWait):
 
 def test_main():
     run_unittest(Wait4Test)
+    reap_children()
 
 if __name__ == "__main__":
     test_main()
diff --git a/Misc/NEWS b/Misc/NEWS
index 9612812db8..8e83867b3c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -48,6 +48,12 @@ Build
 - Bug #1513032: 'make install' failed on FreeBSD 5.3 due to lib-old
   trying to be installed even though it's empty.
 
+Tests
+-----
+
+- Call os.waitpid() at the end of tests that spawn child processes in order
+  to minimize resources (zombies).
+
 
 What's New in Python 2.5 beta 1?
 ================================