Issue 3056 - [cms] Enable threading for the test server

cms/bin/test_server.py

 # coding: utf-8
 
 # This file is part of the Adblock Plus web scripts,
 # Copyright (C) 2006-2015 Eyeo GmbH
 #
 # Adblock Plus is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 3 as
 # published by the Free Software Foundation.
 #
 # Adblock Plus is distributed in the hope that it will be useful,
@@ skipping 105 matching lines @@
 
 if __name__ == "__main__":
   if len(sys.argv) < 2:
     source = FileSource(os.curdir)
   elif os.path.isdir(sys.argv[1]):
     source = FileSource(sys.argv[1])
   else:
     sys.exit("Usage: %s [source_dir]" % sys.argv[0])
 
   try:
-    from werkzeug.serving import run_simple
+    from werkzeug.serving import ThreadedWSGIServer, run_simple
+
+    # see https://github.com/mitsuhiko/werkzeug/pull/770
+    ThreadedWSGIServer.daemon_threads = True
+
     def run(*args, **kwargs):
       # The werkzeug logger must be configured before the
       # root logger. Also we must prevent it from propagating
       # messages, otherwise messages are logged twice.
       import logging
       logger = logging.getLogger("werkzeug")
       logger.propagate = False
       logger.setLevel(logging.INFO)
       logger.addHandler(logging.StreamHandler())
 
       run_simple(threaded=True, *args, **kwargs)
   except ImportError:
     from SocketServer import ThreadingMixIn
     from wsgiref.simple_server import WSGIServer, make_server
 
     class ThreadedWSGIServer(ThreadingMixIn, WSGIServer):

[kzar, 2015/09/15 08:41:41]

Perhaps we should set the daemon_threads attribute to True so that exiting the
server won't wait the 10 seconds for all these stalled connections to close?
(Not sure if there's an equivalent setting for the Werkzeug server?)

[Sebastian Noack, 2015/09/15 15:23:12]

I agree that it would be preferable to have all threads terminate when the main
thread is terminated. In fact, during testing, I reproduced the server hanging
on Ctrl+C when there are still open connections.

However, to make werkzeug use daemon threads you either have to monkey-patch the
undocumented ThreadedWSGIServer class, or duplicate a fair amount of the code
from the run_simple function involving undocumented APIs as well.

I went for monkey patching for now, and submitted a pull request:
https://github.com/mitsuhiko/werkzeug/pull/770

-      pass
+      daemon_threads = True
 
     def run(host, port, app, **kwargs):
       def wrapper(environ, start_response):
         try:
           return app(environ, start_response)
         except Exception, e:
           return show_error(start_response, "500 Internal Server Error",
               uri=environ.get("PATH_INFO"), error=e)
 
       server = make_server(host, port, wrapper, ThreadedWSGIServer)
       print " * Running on http://%s:%i/" % server.server_address
       server.serve_forever()
 
   run("localhost", 5000, handler, use_reloader=True, use_debugger=True)