win: Only retry in UseHandler() loop on ERROR_PIPE_BUSY

snapshot/win/end_to_end_test.py

 #!/usr/bin/env python
 
 # Copyright 2015 The Crashpad Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
 import os
 import platform
 import random
 import re
 import subprocess
 import sys
 import tempfile
+import time
 
 g_temp_dirs = []
 
 
 def MakeTempDir():
   global g_temp_dirs
   new_dir = tempfile.mkdtemp()
   g_temp_dirs.append(new_dir)
   return new_dir
 
@@ skipping 60 matching lines @@
       print 'could not initialize report database'
       return None
 
     if pipe_name is not None:
       handler = subprocess.Popen([
           os.path.join(out_dir, 'crashpad_handler.exe'),
           '--pipe-name=' + pipe_name,
           '--database=' + test_database
       ])
 
+      # Wait until the server is ready.
+      printed = False
+      while not os.path.exists(pipe_name):
+        if not printed:
+          print 'Waiting for crashpad_handler to be ready...'
+          printed = True
+        time.sleep(0.1)
+
       subprocess.call([os.path.join(out_dir, executable_name), pipe_name])
     else:
       subprocess.call([os.path.join(out_dir, executable_name),
                        os.path.join(out_dir, 'crashpad_handler.exe'),
                        test_database])
 
     out = subprocess.check_output([
         os.path.join(out_dir, 'crashpad_database_util.exe'),
         '--database=' + test_database,
         '--show-completed-reports',
@@ skipping 181 matching lines @@
              z7_dump_path,
              pipe_name)
 
     return 0
   finally:
     CleanUpTempDirs()
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))