Shutdown multiprocess pool after running tests to avoid _finalizer spew on Windows

presubmit_support.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Enables directory-specific presubmit checks to run at upload and/or commit.
 """
 
 __version__ = '1.8.0'
 
@@ skipping 545 matching lines @@
         tests.append(t)
         if self.verbose:
           t.info = _PresubmitNotifyResult
     if len(tests) > 1 and parallel:
       # async recipe works around multiprocessing bug handling Ctrl-C
       msgs.extend(self._run_tests_pool.map_async(CallCommand, tests).get(99999))
     else:
       msgs.extend(map(CallCommand, tests))
     return [m for m in msgs if m]
 
+  def ShutdownPool(self):
+    self._run_tests_pool.close()
+    self._run_tests_pool.join()
+    self._run_tests_pool = None
+
 
 class _DiffCache(object):
   """Caches diffs retrieved from a particular SCM."""
   def __init__(self, upstream=None):
     """Stores the upstream revision against which all diffs will be computed."""
     self._upstream = upstream
 
   def GetDiff(self, path, local_root):
     """Get the diff for a particular path."""
     raise NotImplementedError()
@@ skipping 865 matching lines @@
         raise PresubmitFailure(
           'Presubmit functions must return a tuple or list')
       for item in result:
         if not isinstance(item, OutputApi.PresubmitResult):
           raise PresubmitFailure(
             'All presubmit results must be of types derived from '
             'output_api.PresubmitResult')
     else:
       result = ()  # no error since the script doesn't care about current event.
 
+    input_api.ShutdownPool()
+
     # Return the process to the original working directory.
     os.chdir(main_path)
     return result
 
 
 def DoPresubmitChecks(change,
                       committing,
                       verbose,
                       output_stream,
                       input_stream,
@@ skipping 338 matching lines @@
     return 2
 
 
 if __name__ == '__main__':
   fix_encoding.fix_encoding()
   try:
     sys.exit(main())
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(2)