Ensure host_forwarder is killed when setting up/tearing down sharding.

build/android/pylib/forwarder.py

 # 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.
 
 import logging
 import os
 import re
 import sys
 import time
 
@@ skipping 87 matching lines @@
         raise Exception('Unexpected host forwarder output "%s", ' +
                         'expected "device_port:host_port"' % output)
       device_port = int(tokens[0])
       host_port = int(tokens[1])
       self._host_to_device_port_map[host_port] = device_port
       logging.info('Forwarding device port: %d to host port: %d.', device_port,
                    host_port)
 
   @staticmethod
   def KillHost(build_type):
+    logging.info('Killing host_forwarder.')
     host_forwarder_path = _MakeBinaryPath(build_type, 'host_forwarder')
     (exit_code, output) = cmd_helper.GetCmdStatusAndOutput(
         [host_forwarder_path, 'kill-server'])
     if exit_code != 0:
-      raise Exception('%s exited with %d:\n%s' % (host_forwarder_path,
-                                                  exit_code, '\n'.join(output)))
+      (exit_code, output) = cmd_helper.GetCmdStatusAndOutput(
+          ['pkill', 'host_forwarder'])
+      if exit_code != 0:
+        raise Exception('%s exited with %d:\n%s' % (
+              host_forwarder_path, exit_code, '\n'.join(output)))
 
   @staticmethod
   def KillDevice(adb):
     logging.info('Killing device_forwarder.')
     if not adb.FileExistsOnDevice(Forwarder._DEVICE_FORWARDER_PATH):
       return
     (exit_code, output) = adb.GetShellCommandStatusAndOutput(
         '%s kill-server' % Forwarder._DEVICE_FORWARDER_PATH)
     # TODO(pliard): Remove the following call to KillAllBlocking() when we are
     # sure that the old version of device_forwarder (not supporting
     # 'kill-server') is not running on the bots anymore.
     timeout_sec = 5
     processes_killed = adb.KillAllBlocking('device_forwarder', timeout_sec)
     if not processes_killed:
       pids = adb.ExtractPid('device_forwarder')
       if pids:
         raise Exception('Timed out while killing device_forwarder')
 
   def DevicePortForHostPort(self, host_port):
     """Get the device port that corresponds to a given host port."""
     return self._host_to_device_port_map.get(host_port)
 
   def Close(self):
     """Terminate the forwarder process."""
     if self._device_process:
       self._device_process.close()
       self._device_process = None