tools/telemetry/third_party/webpagereplay/daemonserver.py

   1 #!/usr/bin/env python
   2 # Copyright 2010 Google Inc. All Rights Reserved.
   3 #
   4 # Licensed under the Apache License, Version 2.0 (the "License");
   5 # you may not use this file except in compliance with the License.
   6 # You may obtain a copy of the License at
   7 #
   8 #      http://www.apache.org/licenses/LICENSE-2.0
   9 #
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16 import threading
  17
  18
  19 class DaemonServer(object):
  20   """Base class which manages creation and cleanup of daemon style servers."""
  21
  22   def __enter__(self):
  23     # TODO: Because of python's Global Interpreter Lock (GIL), the threads
  24     # will run on the same CPU. Consider using processes instead because
  25     # the components do not need to communicate with each other. On Linux,
  26     # "taskset" could be used to assign each process to specific CPU/core.
  27     # Of course, only bother with this if the processing speed is an issue.
  28     # Some related discussion: http://stackoverflow.com/questions/990102/python-
  29     # global-interpreter-lock-gil-workaround-on-multi-core-systems-using-tasks
  30     thread = threading.Thread(target=self.serve_forever)
  31     thread.daemon = True  # Python exits when no non-daemon threads are left.
  32     thread.start()
  33     return self
  34
  35   def __exit__(self, unused_exc_type, unused_exc_val, unused_exc_tb):
  36     self.cleanup()