sdk/platform-tools/systrace/catapult/telemetry/telemetry/internal/platform/power_monitor/android_temperature_monitor.py

   1 # Copyright 2014 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 logging
   6
   7 from telemetry.internal.platform import power_monitor
   8
   9 try:
  10   from devil.android import device_errors  # pylint: disable=import-error
  11 except ImportError:
  12   device_errors = None
  13
  14
  15 _TEMPERATURE_FILE = '/sys/class/thermal/thermal_zone0/temp'
  16
  17
  18 class AndroidTemperatureMonitor(power_monitor.PowerMonitor):
  19   """
  20   Returns temperature results in power monitor dictionary format.
  21   """
  22   def __init__(self, device):
  23     super(AndroidTemperatureMonitor, self).__init__()
  24     self._device = device
  25
  26   def CanMonitorPower(self):
  27     return self._GetBoardTemperatureCelsius() is not None
  28
  29   def StartMonitoringPower(self, browser):
  30     # don't call _CheckStart() because this is temperature, not power
  31     # therefore, StartMonitoringPower and StopMonitoringPower
  32     # do not need to be paired
  33     pass
  34
  35   def StopMonitoringPower(self):
  36     avg_temp = self._GetBoardTemperatureCelsius()
  37     if avg_temp is None:
  38       return {'identifier': 'android_temperature_monitor'}
  39     else:
  40       return {'identifier': 'android_temperature_monitor',
  41               'platform_info': {'average_temperature_c': avg_temp}}
  42
  43   def _GetBoardTemperatureCelsius(self):
  44     try:
  45       contents = self._device.ReadFile(_TEMPERATURE_FILE)
  46       return float(contents) if contents else None
  47     except ValueError:
  48       logging.warning('String returned from device.ReadFile(_TEMPERATURE_FILE) '
  49                       'in invalid format.')
  50       return None
  51     except device_errors.CommandFailedError:
  52       return None