关于CE 6.0 的powermanager 代码的一点理解

 

发个以前阅读ce 6.0 powermanager default mode  代码的简单分析：

   因为最近玩了下win7的手机,感觉的确快,在同样的硬件设备上,比android  快不是一点点

所以还是看好的win的, 假以时日,一定会卷土重来的!

记得以前CE5.0 下call set power state ,是直接改变电源状态,如果各线程同时调用,会发生状态变化的不完整，所以以前一直通过notify
去改变电源状态,6.0 不同了,估计发现这个问题了,这方面做了改进
另外pdd 层都改成c++的, 代码更清晰了

具体简要分析记录如下:
*  classes
  PowerStateManager(PMSystemAPI)
  PowerState
     other system state derive PowerState

* start sync (关键点在于 m_hNotEmpty 就是SystemPowerStateAPI => GetEventHandle(PM_SYSTEM_API_EVENT))

(PmSetSystemPowerState  call 不到 实际EnterState !!!)
ThreadRun                                    | PmSetSystemPowerState (pm self first
                                             |           call or api call !!!)
GetFirstPowerState (ret CurPowerState)       |   PlatformSendSystemPowerState
*0 GetAPISignalHandle (wait m_hNotEmpty)     |     SendSystemPowerState (carry
                                             |            out the power state change)
**1 RequestComplete(setEvent m_hComplete     |       wait m_hEmpty      {  ( mutex )
pCurPowerState->EnterState(); !!!            |       ResetEvent(m_hComplete);
                                             |       StringCchCopy(m_szStateName, 
                                             |              MAX_PATH,pwsState);!!!实际 
above do enterstate)                         |         *1 SetEvent(m_hNotEmpty);
while (!fDone && pCurPowerState)             |         **0 wait m_hComplete 
 (m_hNotEmpty 就是 SystemPowerStateAPI)      |         setEvent (m_hEmpty) }
 case SystemPowerStateAPI                    |

    apiState=  RequestedSystemPowerState     |
                    *0 wait m_hNotEmpty      |
               PowerState * pNewPowerState = GetStateObject(apiState);

         pCurPowerState = SetSystemState(pCurPowerState ) ;  (=>EnterState!!!)
         if (activityEvent == SystemPowerStateAPI) {
                   RequestComplete();
         }

   上面看出,ce6 上外部call 并不是直接call api 而是走powermanager thread run 流程
  竖线两边表示两个并行运行的部分

* timeout state change:  (除了api call event ,所有时间都减wait time)
  on --(userilde timeout)--->useridle
     --(backlight timeout)-->backlightoff
     --(suspend timeout)---->suspend

  useridle--(suspend timeout)--->unattend            (UserActivity event)-->on

  backlightoff-->(suspend timeout)-------->unattend  (UserActivity event)-->on
  backlightoff-->(UserActivityTimeout)---->useridle

  unattend---->(SuspendTimeout)----->suspend   并且 enter unattend count !=0  说明有unattend 请求
  unattend 当有enter unattend 请求时 PowerManager ThreadRun 最后状态实作时(SetSystemState) 会去call unattend state的
           GetLastNewState 其中判断如果有enter unattend count 请求 next state 仍旧是unattend,否则为suspend

  Resuming---->(all timeout)-------------->unattend 

  suspend (not timeout) to resuming (at extern wakeup)!!!

  比如:
  1.
  userilde timeout = 3
  backlightoff timeout =6
  suspend timeout  =9

  on 不动过3秒 ===>useridle 不动过9秒 ===>unattend===>不动0秒===>suspend
                                          如果请求进入unattend 那么 suspend timeout 重新设置,然后leave unattend 后过9秒入 suspend
  2.
  userilde timeout = 6
  backlightoff timeout =3
  suspend timeout  =9

  on 不动过3秒 ===>backlightoff 不动过3秒 ===>useridle 不动过3秒===>unattend===>不动0秒===>suspend (错)
  
  根据ThreadRun==>SetSystemState =>EnterState ==> ReAdjustTimeOuts  不为infinit  并且getNewstate != cur state,的都重新获得timout时间
  on 不动过3秒 ===>backlightoff 不动过6秒 ===>useridle 不动过9秒===>unattend===>不动0秒===>suspend (对)

  这种情况如果把backlightoff 设置 为半暗, useridle 为全暗 ,这样感觉比较好

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