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/timer/hi_res_timer_manager.h" 6 7 #include "base/power_monitor/power_monitor.h" 8 #include "base/time/time.h" 9 10 namespace base { 11 12 HighResolutionTimerManager::HighResolutionTimerManager() 13 : hi_res_clock_available_(false) { 14 base::PowerMonitor* power_monitor = base::PowerMonitor::Get(); 15 DCHECK(power_monitor != NULL); 16 power_monitor->AddObserver(this); 17 UseHiResClock(!power_monitor->IsOnBatteryPower()); 18 } 19 20 HighResolutionTimerManager::~HighResolutionTimerManager() { 21 base::PowerMonitor::Get()->RemoveObserver(this); 22 UseHiResClock(false); 23 } 24 25 void HighResolutionTimerManager::OnPowerStateChange(bool on_battery_power) { 26 UseHiResClock(!on_battery_power); 27 } 28 29 void HighResolutionTimerManager::UseHiResClock(bool use) { 30 if (use == hi_res_clock_available_) 31 return; 32 hi_res_clock_available_ = use; 33 base::Time::EnableHighResolutionTimer(use); 34 } 35 36 } // namespace base 37