Parallelize pylint PRESUBMIT checks.

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 293 matching lines @@
     self.unittest = unittest
     self.urllib2 = urllib2
 
     # To easily fork python.
     self.python_executable = sys.executable
     self.environ = os.environ
 
     # InputApi.platform is the platform you're currently running on.
     self.platform = sys.platform
 
+    self.cpu_count = multiprocessing.cpu_count()
+
     # The local path of the currently-being-processed presubmit script.
     self._current_presubmit_path = os.path.dirname(presubmit_path)
 
     # We carry the canned checks so presubmit scripts can easily use them.
     self.canned_checks = presubmit_canned_checks
 
     # TODO(dpranke): figure out a list of all approved owners for a repo
     # in order to be able to handle wildcard OWNERS files?
     self.owners_db = owners.Database(change.RepositoryRoot(),
         fopen=file, os_path=self.os_path, glob=self.glob)
@@ skipping 1422 matching lines @@
     return 2
 
 
 if __name__ == '__main__':
   fix_encoding.fix_encoding()
   try:
     sys.exit(main())
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)