base/timer/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_TIMER_HI_RES_TIMER_MANAGER_H_
   6 #define BASE_TIMER_HI_RES_TIMER_MANAGER_H_
   7
   8 #include "base/base_export.h"
   9 #include "base/basictypes.h"
  10 #include "base/power_monitor/power_observer.h"
  11
  12 namespace base {
  13
  14 // Ensures that the Windows high resolution timer is only used
  15 // when not running on battery power.
  16 class BASE_EXPORT HighResolutionTimerManager : public base::PowerObserver {
  17  public:
  18   HighResolutionTimerManager();
  19   virtual ~HighResolutionTimerManager();
  20
  21   // base::PowerObserver method.
  22   virtual void OnPowerStateChange(bool on_battery_power) OVERRIDE;
  23
  24   // Returns true if the hi resolution clock could be used right now.
  25   bool hi_res_clock_available() const { return hi_res_clock_available_; }
  26
  27  private:
  28   // Enable or disable the faster multimedia timer.
  29   void UseHiResClock(bool use);
  30
  31   bool hi_res_clock_available_;
  32
  33   DISALLOW_COPY_AND_ASSIGN(HighResolutionTimerManager);
  34 };
  35
  36 }  // namespace base
  37
  38 #endif  // BASE_TIMER_HI_RES_TIMER_MANAGER_H_