base/hi_res_timer_manager_win.cc

   1 // Copyright (c) 2011 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 #include "base/hi_res_timer_manager.h"
   6
   7 #include "base/power_monitor/power_monitor.h"
   8 #include "base/time.h"
   9
  10 HighResolutionTimerManager::HighResolutionTimerManager()
  11     : hi_res_clock_available_(false) {
  12   base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
  13   power_monitor->AddObserver(this);
  14   UseHiResClock(!power_monitor->BatteryPower());
  15 }
  16
  17 HighResolutionTimerManager::~HighResolutionTimerManager() {
  18   base::PowerMonitor::Get()->RemoveObserver(this);
  19   UseHiResClock(false);
  20 }
  21
  22 void HighResolutionTimerManager::OnPowerStateChange(bool on_battery_power) {
  23   UseHiResClock(!on_battery_power);
  24 }
  25
  26 void HighResolutionTimerManager::UseHiResClock(bool use) {
  27   if (use == hi_res_clock_available_)
  28     return;
  29   hi_res_clock_available_ = use;
  30   base::Time::EnableHighResolutionTimer(use);
  31 }