Use exit command to stop web page replay server.

chrome/test/functional/webpagereplay.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 """Start and stop Web Page Replay.
 
 Of the public module names, the following one is key:
   ReplayServer: a class to start/stop Web Page Replay.
 """
@@ skipping 17 matching lines @@
 
 # Chrome options to make it work with Web Page Replay.
 def GetChromeFlags(replay_host, http_port, https_port):
   return [
       '--host-resolver-rules=MAP * %s,EXCLUDE localhost' % replay_host,
       '--testing-fixed-http-port=%s' % http_port,
       '--testing-fixed-https-port=%s' % https_port,
       '--ignore-certificate-errors',
       ]
 
+
 # Signal masks on Linux are inherited from parent processes.  If anything
 # invoking us accidentally masks SIGINT (e.g. by putting a process in the
 # background from a shell script), sending a SIGINT to the child will fail
 # to terminate it.  Running this signal handler before execing should fix that
 # problem.
 def ResetInterruptHandler():
   signal.signal(signal.SIGINT, signal.SIG_DFL)
 
+
 class ReplayError(Exception):
   """Catch-all exception for the module."""
   pass
 
+
 class ReplayNotFoundError(ReplayError):
   def __init__(self, label, path):
     self.args = (label, path)
 
   def __str__(self):
     label, path = self.args
     return 'Path does not exist for %s: %s' % (label, path)
 
+
 class ReplayNotStartedError(ReplayError):
   pass
 
 
 class ReplayServer(object):
   """Start and Stop Web Page Replay.
 
   Web Page Replay is a proxy that can record and "replay" web pages with
   simulated network characteristics -- without having to edit the pages
   by hand. With WPR, tests can use "real" web content, and catch
   performance issues that may result from introducing network delays and
   bandwidth throttling.
 
   Example:
      with ReplayServer(archive_path):
        self.NavigateToURL(start_url)
        self.WaitUntil(...)
 
   Environment Variables (for development):
     WPR_ARCHIVE_PATH: path to alternate archive file (e.g. '/tmp/foo.wpr').
     WPR_RECORD: if set, puts Web Page Replay in record mode instead of replay.
     WPR_REPLAY_DIR: path to alternate Web Page Replay source.
   """
+
   def __init__(self, archive_path, replay_host, http_port, https_port,
                replay_options=None, replay_dir=None,
                log_path=None):
     """Initialize ReplayServer.
 
     Args:
       archive_path: a path to a specific WPR archive (required).
       replay_options: an iterable of options strings to forward to replay.py.
       replay_dir: directory that has replay.py and related modules.
       log_path: a path to a log file.
-   """
+    """
     self.archive_path = os.environ.get('WPR_ARCHIVE_PATH', archive_path)
     self.replay_options = list(replay_options or ())
     self.replay_dir = os.environ.get('WPR_REPLAY_DIR', replay_dir or REPLAY_DIR)
     self.log_path = log_path or LOG_PATH
     self._http_port = http_port
     self._https_port = https_port
     self._replay_host = replay_host
 
     if 'WPR_RECORD' in os.environ and '--record' not in self.replay_options:
       self.replay_options.append('--record')
@@ skipping 46 matching lines @@
             200 == urllib.urlopen(https_up_url, None, {}).getcode()):
           return True
       except IOError:
         time.sleep(1)
     return False
 
   def StartServer(self):
     """Start Web Page Replay and verify that it started.
 
     Raises:
-      ReplayNotStartedError if Replay start-up fails.
+      ReplayNotStartedError: if Replay start-up fails.
     """
     cmd_line = [sys.executable, self.replay_py]
     cmd_line.extend(self.replay_options)
     cmd_line.append(self.archive_path)
     self.log_fh = self._OpenLogFile()
     logging.debug('Starting Web-Page-Replay: %s', cmd_line)
-    kwargs = { 'stdout': self.log_fh, 'stderr': subprocess.STDOUT }
+    kwargs = {'stdout': self.log_fh, 'stderr': subprocess.STDOUT}
     if sys.platform.startswith('linux') or sys.platform == 'darwin':
       kwargs['preexec_fn'] = ResetInterruptHandler
     self.replay_process = subprocess.Popen(cmd_line, **kwargs)
     if not self.IsStarted():
       log = open(self.log_path).read()
       raise ReplayNotStartedError(
           'Web Page Replay failed to start. Log output:\n%s' % log)
 
   def StopServer(self):
     """Stop Web Page Replay."""
     if self.replay_process:
-      logging.debug('Stopping Web-Page-Replay')
-      # Use a SIGINT so that it can do graceful cleanup. On Windows, we are left
-      # with no other option than terminate().
+      logging.debug('Trying to stop Web-Page-Replay gracefully')
       try:
-        self.replay_process.send_signal(signal.SIGINT)
-      except:
-        self.replay_process.terminate()
-      self.replay_process.wait()
+        url = 'http://localhost:%s/web-page-replay-command-exit'
+        urllib.urlopen(url % self._http_port, None, {})
+      except IOError:
+        # IOError is possible because the server might exit without response.
+        pass
+
+      start_time = time.time()
+      while time.time() - start_time < 10:  # Timeout after 10 seconds.
+        if self.replay_process.poll() is not None:
+          break
+        time.sleep(1)
+      else:
+        try:
+          # Use a SIGINT so that it can do graceful cleanup.

[kkania, 2013/08/29 15:30:14]

would it be simpler at this point to just do a force kill instead of going
through another attempt at graceful cleanup?

[chrisgao (Use stgao instead), 2013/08/29 20:54:26]

As discussed offline, keep the current approach.

+          self.replay_process.send_signal(signal.SIGINT)
+        except:  # pylint: disable=W0702
+          # On Windows, we are left with no other option than terminate().
+          if 'no-dns_forwarding' not in self.replay_options:
+            logging.warning('DNS configuration might not be restored!')
+          try:
+            self.replay_process.terminate()
+          except:  # pylint: disable=W0702
+            pass
+        self.replay_process.wait()
     if self.log_fh:
       self.log_fh.close()
 
   def __enter__(self):
     """Add support for with-statement."""
     self.StartServer()
     return self
 
   def __exit__(self, unused_exc_type, unused_exc_val, unused_exc_tb):
     """Add support for with-statement."""
     self.StopServer()