[转]WM/WINCE代码研读系列之Power Management(4)

下面是PmSetSystemPowerState函数的详细内容

PmSetSystemPowerState
{
    PlatformSendSystemPowerState
    {
        SendSystemPowerState
        {
              PlatformMapPowerStateHint;   //将StateFlags转化成电源状态名
              {
                        对应关系如下：
                        POWER_STATE_ON -- _T("on");
                        POWER_STATE_IDLE -- _T("screenoff");
                        POWER_STATE_SUSPEND -- _T("suspend");
                        POWER_STATE_OFF -- _T("suspend");
                        POWER_STATE_CRITICAL -- _T("suspend");
                        POWER_STATE_RESET -- _T("reboot");
                        POWER_STATE_USERIDLE -- _T("useridle");
                }
 
                //下面两个函数由要设置的电源状态名得到相应的对象指针
                SystemStateToActivityState
                GetStateObject
 
                AppsCanRequestState           //判断要设置的电源状态是否可以被设置
                if((dwOptions & POWER_DUMPDW)!=0)
                {
                          //Options 参数带POWER_DUMPDW 时会产生Dr. Watson dump file.
                          CaptureDumpFileOnDevice; 
                 }
                 pNewPowerState->EnterState();//这里是实质的设置函数
 
                 //将电源状态的状态机转至设置的系统电源状态
                 pNewPowerState = SetSystemState(pNewPowerState);
                 m_pCurPowerState = pNewPowerState;
 
             //将ResumingSuspendTimeout,SuspendTimeout,BacklightTimeout,UserIdleTimeout这几个定时器复位
                 ReInitTimeOuts(FALSE);
 
                //通知PowerStateManager::ThreadRun,这里没有做实质性内容
                SetEvent(m_hSystemApiCalled);
          }
      }
}