base/hi_res_timer_manager.h

   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 #ifndef BASE_HI_RES_TIMER_MANAGER_H_
   6 #define BASE_HI_RES_TIMER_MANAGER_H_
   7
   8 #include "base/base_export.h"
   9 #include "base/system_monitor/system_monitor.h"
  10
  11 // Ensures that the Windows high resolution timer is only used
  12 // when not running on battery power.
  13 class BASE_EXPORT HighResolutionTimerManager
  14     : public base::SystemMonitor::PowerObserver {
  15  public:
  16   HighResolutionTimerManager();
  17   virtual ~HighResolutionTimerManager();
  18
  19   // base::SystemMonitor::PowerObserver:
  20   virtual void OnPowerStateChange(bool on_battery_power) OVERRIDE;
  21
  22   // Returns true if the hi resolution clock could be used right now.
  23   bool hi_res_clock_available() const { return hi_res_clock_available_; }
  24
  25  private:
  26   // Enable or disable the faster multimedia timer.
  27   void UseHiResClock(bool use);
  28
  29   bool hi_res_clock_available_;
  30
  31   DISALLOW_COPY_AND_ASSIGN(HighResolutionTimerManager);
  32 };
  33
  34 #endif  // BASE_HI_RES_TIMER_MANAGER_H_