base/hi_res_timer_manager.h


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// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_HI_RES_TIMER_MANAGER_H_
#define BASE_HI_RES_TIMER_MANAGER_H_

#include "base/base_export.h"
#include "base/system_monitor/system_monitor.h"

// Ensures that the Windows high resolution timer is only used
// when not running on battery power.
class BASE_EXPORT HighResolutionTimerManager
    : public base::SystemMonitor::PowerObserver {
 public:
  HighResolutionTimerManager();
  virtual ~HighResolutionTimerManager();

  // base::SystemMonitor::PowerObserver:
  virtual void OnPowerStateChange(bool on_battery_power) OVERRIDE;

  // Returns true if the hi resolution clock could be used right now.
  bool hi_res_clock_available() const { return hi_res_clock_available_; }

 private:
  // Enable or disable the faster multimedia timer.
  void UseHiResClock(bool use);

  bool hi_res_clock_available_;

  DISALLOW_COPY_AND_ASSIGN(HighResolutionTimerManager);
};

#endif  // BASE_HI_RES_TIMER_MANAGER_H_