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.

13 files changed, 52 insertions, 8 deletions

diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index 504a6d7..79acc07 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 ec860d1..5e89863 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 0f7d15f..b72a1b9 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 cba5fc7..e909844 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 474354f..2f8cb8d 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 2b687ad..fbf5e05 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 4db3cd1..2d54eb0 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 eaec52b..d341324 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 9316547..dd4532f 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 9877f51..b4e6c00 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 8e31549..6532c79 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 f6a41a6..8279973 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 027e5c3..711fd2d 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()