Make multiple attempts to write binding files to disc

tools/dom/scripts/multiemitter.py

 #!/usr/bin/python
 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 """Templating to help generate structured text."""
 
 import os
-import re

[kustermann, 2013/07/04 11:54:16]

"re" was unused

 import sys
 import subprocess
+import time
 import emitter
 import logging
 
 _logger = logging.getLogger('multiemitter')
 
 class MultiEmitter(object):
   """A set of Emitters that write to different files.
 
   Each entry has a key.
 
@@ skipping 56 matching lines @@
       os.makedirs(dir)
 
   # Remove file if pre-existing.
   if os.path.exists(path):
     _logger.info('Removing - %s' % path)
     os.remove(path)
     if os.path.exists(path):
       _logger.info('Warning: File still exists- %s' % path)
 
   # Write the file.
-  try:
-    _logger.info('Writing - %s' % path)
-    f = open(path, 'w')
-    f.writelines(lines)
-    f.close()
-  except IOError as error:
-    # FIXME(kustermann): Remove this later on.
-    # We try to get more debugging information to figure out why we sometimes
-    # get a "Permission denied" error when opening the file for writing.
-    # (hypothesis: Another process has already opened the file.)
-    _logger.info('Got exception (%s) ' % error)
+  num_attempts = 4
+  for i in range(num_attempts):
+    try:
+      _logger.info('Writing (attempt %d) - %s' % (i + 1, path))
+      f = open(path, 'w')
+      f.writelines(lines)
+      f.close()
+      return
+    except IOError as error:
+      last_attempt = (i == (num_attempts - 1))
+      if not last_attempt:
+        # Sleep for 50 ms and try again
+        time.sleep(0.05)
+      else:
+        # FIXME(kustermann): Remove this later on.
+        # We try to get more debugging information to figure out why we
+        # sometimes get a "Permission denied" error when opening the file for
+        # writing. (hypothesis: Another process has already opened the file.)
+        _logger.info('Got exception (%s) ' % error)
 
-    if sys.platform  == 'win32':
-      handle_file = r'E:\handle.exe'
-      if os.path.exists(handle_file):
-        _logger.info('Running handle.exe for debugging purposes')
-        subprocess.call([handle_file, '-a', r'E:\b\build\slave'])
-      else:
-        _logger.info("Couldn't find %s. Not printing open handles."
-                     % handle_file)
-    raise error
+        if sys.platform  == 'win32':
+          handle_file = r'E:\handle.exe'
+          if os.path.exists(handle_file):
+            _logger.info('Running handle.exe for debugging purposes')
+            subprocess.call([handle_file, '-a', r'E:\b\build\slave'])
+          else:
+            _logger.info("Couldn't find %s. Not printing open handles."
+                         % handle_file)
+        raise error
+