tools/profile_chrome/chrome_startup_controller.py

   1 # Copyright 2015 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 import os
   6 import re
   7 import time
   8
   9 from pylib import flag_changer
  10 from pylib.device import intent
  11 from pylib.perf import cache_control
  12
  13 from profile_chrome import controllers
  14
  15 class ChromeStartupTracingController(controllers.BaseController):
  16   def __init__(self, device, package_info, cold, url):
  17     self._device = device
  18     self._package_info = package_info
  19     self._cold = cold
  20     self._logcat_monitor = self._device.GetLogcatMonitor()
  21     self._url = url
  22     self._trace_file = None
  23     self._trace_finish_re = re.compile(r' Completed startup tracing to (.*)')
  24
  25   def __repr__(self):
  26     return 'Browser Startup Trace'
  27
  28   def _SetupTracing(self):
  29     # TODO(lizeb): Figure out how to clean up the command-line file when
  30     # _TearDownTracing() is not executed in StopTracing().
  31     changer = flag_changer.FlagChanger(
  32         self._device, self._package_info.cmdline_file)
  33     changer.AddFlags(['--trace-startup'])
  34     self._device.ForceStop(self._package_info.package)
  35     if self._cold:
  36       self._device.EnableRoot()
  37       cache_control.CacheControl(self._device).DropRamCaches()
  38     self._device.StartActivity(
  39         intent.Intent(
  40             package=self._package_info.package,
  41             activity=self._package_info.activity,
  42             data=self._url,
  43             extras={'create_new_tab' : True}), blocking=True)
  44
  45   def _TearDownTracing(self):
  46     changer = flag_changer.FlagChanger(
  47         self._device, self._package_info.cmdline_file)
  48     changer.RemoveFlags(['--trace-startup'])
  49
  50   def StartTracing(self, interval):
  51     self._SetupTracing()
  52     self._logcat_monitor.Start()
  53
  54   def StopTracing(self):
  55     try:
  56       self._trace_file = self._logcat_monitor.WaitFor(
  57           self._trace_finish_re).group(1)
  58     finally:
  59       self._TearDownTracing()
  60
  61   def PullTrace(self):
  62     # Wait a bit for the browser to finish writing the trace file.
  63     time.sleep(3)
  64     trace_file = self._trace_file.replace('/storage/emulated/0/', '/sdcard/')
  65     host_file = os.path.join(os.path.curdir, os.path.basename(trace_file))
  66     self._device.PullFile(trace_file, host_file)
  67     return host_file