src/tools/telemetry/telemetry/core/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 telemetry.core.platform.power_monitor as power_monitor
   6
   7 _TEMPERATURE_FILE = '/sys/class/thermal/thermal_zone0/temp'
   8
   9
  10 class AndroidTemperatureMonitor(power_monitor.PowerMonitor):
  11   """
  12   Delegates monitoring to another PowerMonitor and adds temperature measurements
  13   to overall results.
  14   """
  15   def __init__(self, monitor, device):
  16     super(AndroidTemperatureMonitor, self).__init__()
  17     self._device = device
  18     self._power_monitor = monitor
  19     self._can_monitor_with_power_monitor = None
  20
  21   def CanMonitorPower(self):
  22     self._can_monitor_with_power_monitor = (
  23         self._power_monitor.CanMonitorPower())
  24     # Always report ability to monitor power to be able to provide temperature
  25     # metrics and other useful power-related data from sensors.
  26     return True
  27
  28   def StartMonitoringPower(self, browser):
  29     if self._can_monitor_with_power_monitor:
  30       self._power_monitor.StartMonitoringPower(browser)
  31
  32   def StopMonitoringPower(self):
  33     if self._can_monitor_with_power_monitor:
  34       power_data = self._power_monitor.StopMonitoringPower()
  35     else:
  36       power_data = {'identifier': 'android_temperature_monitor'}
  37
  38     # Take the current temperature as average based on the assumption that the
  39     # temperature changes slowly during measurement time.
  40     average_temperature = self._GetBoardTemperatureCelsius()
  41     if average_temperature is None:
  42       return power_data
  43
  44     # Insert temperature into the appropriate position in the dictionary
  45     # returned by StopMonitoringPower() creating appropriate sub-dictionaries on
  46     # the way if necessary.
  47     temperature_path = [
  48         'component_utilization', 'whole_package', 'average_temperature_c']
  49     temperature_insertion_point = power_data
  50     for path_element in temperature_path[:-1]:
  51       if not path_element in temperature_insertion_point:
  52         temperature_insertion_point[path_element] = {}
  53       temperature_insertion_point = temperature_insertion_point[path_element]
  54     assert temperature_path[-1] not in temperature_insertion_point
  55     temperature_insertion_point[temperature_path[-1]] = average_temperature
  56
  57     return power_data
  58
  59   def _GetBoardTemperatureCelsius(self):
  60     contents = self._device.ReadFile(_TEMPERATURE_FILE)
  61     if len(contents) > 0:
  62       return float(contents[0])
  63     return None