Migrate device_utils.RestartServer to adb_wrapper

build/android/pylib/device/adb_wrapper.py

 # Copyright 2013 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.
 
 """This module wraps Android's adb tool.
 
 This is a thin wrapper around the adb interface. Any additional complexity
 should be delegated to a higher level (ex. DeviceUtils).
 """
 
@@ skipping 40 matching lines @@
       device_serial: The device serial number as a string.
     """
     if not device_serial:
       raise ValueError('A device serial must be specified')
     self._device_serial = str(device_serial)
 
   # pylint: disable=unused-argument
   @classmethod
   @decorators.WithTimeoutAndRetries
   def _RunAdbCmd(cls, args, timeout=None, retries=None, device_serial=None,
-                 check_error=True):
-    cmd = [constants.GetAdbPath()]
+                 check_error=True, cpu_affinity=None):

[jbudorick, 2014/12/11 01:43:13]

Probably doesn't surprise you to hear that I'm not a fan of adding arguments for
a one-off, although I'm not immediately sure how else you'd do this since it
needs to precede the adb call.

[perezju, 2014/12/11 11:38:00]

Yeah, I don't like this too much either. But couldn't think of other way to
achieve what was needed. Also I don't think setting the cpu_affinity should be a
matter of DeviceUtils, because it's really an issue of adb (imagine a
theoretical PyAdbWrapper, presumably this "fix" for adb instability shouldn't be
needed at all).

[jbudorick, 2014/12/11 16:27:17]

Agreed.

+    if cpu_affinity is not None:
+      cmd = ['taskset', '-c', str(cpu_affinity)]

[jbudorick, 2014/12/11 01:43:13]

How is this going to interact with _BuildAdbCmd in your Logcat CL?

[perezju, 2014/12/11 11:38:00]

I think cpu_affinity (or something like that) would end up as an option to
_BuildAdbCmd. And yes, one of the two CLs should land first, and the other will
have to be rebased against the first one.

+    else:
+      cmd = []
+    cmd.append(constants.GetAdbPath())
     if device_serial is not None:
       cmd.extend(['-s', device_serial])
     cmd.extend(args)
     status, output = cmd_helper.GetCmdStatusAndOutputWithTimeout(
         cmd, timeout_retry.CurrentTimeoutThread().GetRemainingTime())
     if status != 0:
       raise device_errors.AdbCommandFailedError(
           args, output, status, device_serial)
     # This catches some errors, including when the device drops offline;
     # unfortunately adb is very inconsistent with error reporting so many
@@ skipping 35 matching lines @@
     """The string representation of an instance.
 
     Returns:
       The device serial number as a string.
     """
     return self._device_serial
 
   def __repr__(self):
     return '%s(\'%s\')' % (self.__class__.__name__, self)
 
+  @classmethod
+  def KillServer(cls, timeout=_DEFAULT_TIMEOUT, retries=_DEFAULT_RETRIES):
+    cls._RunAdbCmd(['kill-server'], timeout=timeout, retries=retries)
+
+  @classmethod
+  def StartServer(cls, timeout=_DEFAULT_TIMEOUT, retries=_DEFAULT_RETRIES):
+    # CPU affinity is used to reduce adb instability http://crbug.com/268450
+    cls._RunAdbCmd(['start-server'], timeout=timeout, retries=retries,
+                   cpu_affinity=0)
+
   # TODO(craigdh): Determine the filter criteria that should be supported.
   @classmethod
   def GetDevices(cls, timeout=_DEFAULT_TIMEOUT, retries=_DEFAULT_RETRIES):
     """Get the list of active attached devices.
 
     Args:
       timeout: (optional) Timeout per try in seconds.
       retries: (optional) Number of retries to attempt.
 
     Yields:
@@ skipping 310 matching lines @@
     """Restarts the adbd daemon with root permissions, if possible.
 
     Args:
       timeout: (optional) Timeout per try in seconds.
       retries: (optional) Number of retries to attempt.
     """
     output = self._RunDeviceAdbCmd(['root'], timeout, retries)
     if 'cannot' in output:
       raise device_errors.AdbCommandFailedError(
           ['root'], output, device_serial=self._device_serial)