Android: makes "RestartAdbdOnDevice" more robust.

build/android/pylib/android_commands.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.
 
 """Provides an interface to communicate with the device via the adb command.
 
 Assumes adb binary is currently on system path.
 """
 
 import collections
@@ skipping 447 matching lines @@
         reboots_left -= 1
 
   def MakeSystemFolderWritable(self):
     """Remounts the /system folder rw."""
     out = self._adb.SendCommand('remount')
     if out.strip() != 'remount succeeded':
       raise errors.MsgException('Remount failed: %s' % out)
 
   def RestartAdbdOnDevice(self):
     logging.info('Killing adbd on the device...')
-    adb_pids = self.KillAll('adbd', signal=signal.SIGTERM, with_su=True)
-    assert adb_pids, 'Unable to obtain adbd pid'
-    logging.info('Waiting for device to settle...')
-    self._adb.SendCommand('wait-for-device')
+    try:
+      if not self.KillAll('adbd', signal=signal.SIGTERM, with_su=True):
+        logging.error('Unable to obtain adbd pid')
+      logging.info('Waiting for device to settle...')
+      self._adb.SendCommand('wait-for-device')

[tonyg, 2013/11/27 16:24:15]

The idea of this wait-for-device is that it must be done after killing adbd.
However, if it needs to be done for some other reason, then callers are relying
on an unintended side effect of this method.

I think we should only do this if we actually kill adbd. That will flush out any
callers or other places that need their own wait-for-device for other reasons.

[bulach, 2013/11/27 18:04:27]

you're right. I was mistaken, KillAll just returns the len of pids it sent the
signal to, no guarantees if the procs were actually restarted...
I made it slightly more robust by checking that the pid has indeed changed, and
printing an error if they haven't. wdyt?

+    except Except as e:

[tonyg, 2013/11/27 16:24:15]

s/Except/Exception/ -- no?

[bulach, 2013/11/27 18:04:27]

facepalm :(

+      logging.error('Exception when trying to kill adbd on the device [%s]', e)
 
   def RestartAdbServer(self):
     """Restart the adb server."""
     ret = self.KillAdbServer()
     if ret != 0:
       raise errors.MsgException('KillAdbServer: %d' % ret)
 
     ret = self.StartAdbServer()
     if ret != 0:
       raise errors.MsgException('StartAdbServer: %d' % ret)
@@ skipping 1221 matching lines @@
   """
   def __init__(self, output):
     self._output = output
 
   def write(self, data):
     data = data.replace('\r\r\n', '\n')
     self._output.write(data)
 
   def flush(self):
     self._output.flush()