Address comments in 8921029 extract_from_cab script now takes a global lock while extracting fro...

build/extract_from_cab.py

 #!/usr/bin/env python
 # Copyright (c) 2011 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.
 
 """Extracts a single file from a CAB archive."""
 
 import os
 import subprocess
 import sys
 import tempfile
 
 lock_file = os.path.join(tempfile.gettempdir(), 'expand.lock')
 
+
 def acquire_lock():
   while True:
     try:
       fd = os.open(lock_file, os.O_CREAT | os.O_EXCL | os.O_RDWR)
       return fd
     except OSError as e:
       if e.errno != errno.EEXIST:
         raise
-      print 'Cab extraction could not get exclusive lock. Retrying in 1 sec...'
-      time.sleep(1000)
+      print 'Cab extraction could not get exclusive lock. Retrying in 100ms...'
+      time.sleep(0.1)
+
 
 def release_lock(fd):
   os.close(fd)
   os.unlink(lock_file)
 
+
 def main():
   if len(sys.argv) != 4:
     print 'Usage: extract_from_cab.py cab_path archived_file output_dir'
     return 1
 
   [cab_path, archived_file, output_dir] = sys.argv[1:]
 
   lock_fd = acquire_lock()
   try:
     # Invoke the Windows expand utility to extract the file.
     level = subprocess.call(
         ['expand', cab_path, '-F:' + archived_file, output_dir])
     if level != 0:
-      print 'Cab extraction(%s, %s, %s) failed.' % (
-          cab_path, archived_file, output_dir)
-      print 'Trying a second time.'
-      level = subprocess.call(
-          ['expand', cab_path, '-F:' + archived_file, output_dir])
-      if level != 0:
-        return level
+      return level
   finally:
     release_lock(lock_fd)
 
   # The expand utility preserves the modification date and time of the archived
   # file. Touch the extracted file. This helps build systems that compare the
   # modification times of input and output files to determine whether to do an
   # action.
   os.utime(os.path.join(output_dir, archived_file), None)
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())