Android60 亮屏灭屏流程DisplayPowerControlerWMS二亮度设置Word格式文档下载.docx
《Android60 亮屏灭屏流程DisplayPowerControlerWMS二亮度设置Word格式文档下载.docx》由会员分享，可在线阅读，更多相关《Android60 亮屏灭屏流程DisplayPowerControlerWMS二亮度设置Word格式文档下载.docx（16页珍藏版）》请在冰豆网上搜索。
mScreenUpdatePending=false;
intbrightness=mScreenState!
=Display.STATE_OFF
&
&
mColorFadeLevel>
0f?
mScreenBrightness:
0;
if（mPhotonicModulator.setState（mScreenState,brightness））{
Screenready"
）;
mScreenReady=true;
invokeCleanListenerIfNeeded（）;
}else{
Screennotready"
};
DisplayPowerState的设置亮度状态逻辑分析
mPhotonicModulator.setState应该要PhotonicModulator的run函数结合一起看。
publicbooleansetState（intstate,intbacklight）{
synchronized（mLock）{
booleanstateChanged=state!
=mPendingState;
booleanbacklightChanged=backlight!
=mPendingBacklight;
if（stateChanged||backlightChanged）{
Requestingnewscreenstate:
+Display.stateToString（state）+"
backlight="
+backlight）;
mPendingState=state;
mPendingBacklight=backlight;
booleanchangeInProgress=mStateChangeInProgress||mBacklightChangeInProgress;
mStateChangeInProgress=stateChanged;
mBacklightChangeInProgress=backlightChanged;
if（!
changeInProgress）{
Slog.d（TAG,"
notifysetbacklightthreadrun"
mLock.notifyAll（）;
return!
mStateChangeInProgress;
两者结合看先setState设置了状态，只有状态改变时，我们才能重新设置状态（设置到mpendingState和mPendingBacklight）。
而在run函数中，当设置的状态mPendingState、mPendingBacklight和mActualState、mActualBacklight（真正设置到背光的状态、亮度）不一样时，才会调用mBlanker.requestDisplayState设置亮度。
否则状态没有改变，就会把mStateChangeInProgress和mBacklightChangeInProgress设置为false，然后线程就wait住。
而此时setState重新设置下来的话，这个时候把亮度和状态设置到mPendingState和mPendingBacklight。
然后这时mStateChangeInProgress和mBacklightChangeInProgress都是false。
这样就可以调用mLock的notifyAll函数重新唤醒线程，这样就把把前面setState设置下来的mPendingState和mPendingBacklight再通过mBlanker.requestDisplayState设置到背光设备中去。
@Override
publicvoidrun（）{
for（;
;
）{
//Getpendingchange.
finalintstate;
finalbooleanstateChanged;
finalintbacklight;
finalbooleanbacklightChanged;
state=mPendingState;
stateChanged=（state!
=mActualState）;
backlight=mPendingBacklight;
backlightChanged=（backlight!
=mActualBacklight）;
stateChanged）{
//Statechangedapplied,notifyouterclass.
postScreenUpdateThreadSafe（）;
mStateChangeInProgress=false;
backlightChanged）{
mBacklightChangeInProgress=false;
stateChanged&
!
try{
mLock.wait（）;
}catch（InterruptedExceptionex）{}
continue;
mActualState=state;
mActualBacklight=backlight;
//Applypendingchange.
if（true）{
Updatingscreenstate:
mBlanker.requestDisplayState（state,backlight）;
kangchenUpdatingscreenstate:
设置亮度、状态到背光设备
DisplayBlanker的requestDisplayState如下，主要调用requestGlobalDisplayStateInternal函数。
DisplayBlankerblanker=newDisplayBlanker（）{
publicvoidrequestDisplayState（intstate,intbrightness）{
//Theorderofoperationsisimportantforlegacyreasons.
if（state==Display.STATE_OFF）{
requestGlobalDisplayStateInternal（state,brightness）;
callbacks.onDisplayStateChange（state）;
if（state!
=Display.STATE_OFF）{
requestGlobalDisplayStateInternal函数先是对state和brightness的处理，然后把这个两个变量放在mGlobalDisplayState和mGlobalDisplayBrightness成员变量中。
紧接着调用applyGlobalDisplayStateLocked函数mTempDisplayStateWorkQueue作为参数。
最后再调用mTempDisplayStateWorkQueue各个成员的run函数（这里返回的是Runnable接口，这里就会设置状态和亮度到设备中去）。
privatevoidrequestGlobalDisplayStateInternal（intstate,intbrightness）{
if（state==Display.STATE_UNKNOWN）{
state=Display.STATE_ON;
brightness=PowerManager.BRIGHTNESS_OFF;
}elseif（brightness<
0）{
brightness=PowerManager.BRIGHTNESS_DEFAULT;
}elseif（brightness>
PowerManager.BRIGHTNESS_ON）{
brightness=PowerManager.BRIGHTNESS_ON;
synchronized（mTempDisplayStateWorkQueue）{
synchronized（mSyncRoot）{
if（mGlobalDisplayState==state
mGlobalDisplayBrightness==brightness）{
return;
//nochange
mGlobalDisplayState=state;
mGlobalDisplayBrightness=brightness;
applyGlobalDisplayStateLocked（mTempDisplayStateWorkQueue）;
//Settingthedisplaypowerstatecantakehundredsofmilliseconds
//tocompletesowedeferthemostexpensivepartoftheworkuntil
//afterwehaveexitedthecriticalsectiontoavoidblockingother
//threadsforalongtime.
for（inti=0;
i<
mTempDisplayStateWorkQueue.size（）;
i++）{
mTempDisplayStateWorkQueue.get（i）.run（）;
//设置亮度、状态到设备
}finally{
mTempDisplayStateWorkQueue.clear（）;
applyGlobalDisplayStateLocked函数会遍历各个显示设备（多显示），然后调用updateDisplayStateLocked函数返回一个Runnable，最后把这个Runnable放入之前传入的mTempDisplayStateWorkQueue队列中。
privatevoidapplyGlobalDisplayStateLocked（List<
Runnable>
workQueue）{
finalintcount=mDisplayDevices.size（）;
count;
DisplayDevicedevice=mDisplayDevices.get（i）;
Runnablerunnable=updateDisplayStateLocked（device）;
if（runnable!
=null）{
workQueue.add（runnable）;
那下面我们看下updateDisplayStateLocked函数，主要是调用了DisplayDevice的requestDisplayStateLocked函数，当然mGlobalDisplayState和mGlobalDisplayBrightness作为参数。
privateRunnableupdateDisplayStateLocked（DisplayDevicedevice）{
//Blankorunblankthedisplayimmediatelytomatchthestaterequested
//bythedisplaypowercontroller（ifknown）.
DisplayDeviceInfoinfo=device.getDisplayDeviceInfoLocked（）;
if（（info.flags&
DisplayDeviceInfo.FLAG_NEVER_BLANK）==0）{
returndevice.requestDisplayStateLocked（mGlobalDisplayState,mGlobalDisplayBrightness）;
returnnull;
这里的DisplayDevice的requestDisplayStateLocked函数，是在LocalDisplayAdapter中实现的，这里吧state和brightness保存在mState和mBrightness中，然后返回Runnable接口，最后在Runnable接口中设置亮度和状态。
publicRunnablerequestDisplayStateLocked（finalintstate,finalintbrightness）{
//Assumethatthebrightnessisoffifthedisplayisbeingturnedoff.
assertstate!
=Display.STATE_OFF||brightness==PowerManager.BRIGHTNESS_OFF;
finalbooleanstateChanged=（mState!
=state）;
finalbooleanbrightnessChanged=（mBrightness!
=brightness）&
mBacklight!
=null;
if（stateChanged||brightnessChanged）{
finalintdisplayId=mBuiltInDisplayId;
finalIBindertoken=getDisplayTokenLocked（）;
finalintoldState=mState;
if（stateChanged）{
mState=state;
//保存state
updateDeviceInfoLocked（）;
if（brightnessChanged）{
mBrightness=brightness;
//保存brightness
//Deferactuallysettingthedisplaystateuntilafterwehaveexited
//thecriticalsectionsinceitcantakehundredsofmilliseconds
//tocomplete.
returnnewRunnable（）{//返回Runnable
//Exitasuspendedstatebeforemakinganychanges.
intcurrentState=oldState;
if（Display.isSuspendedState（oldState）
||oldState==Display.STATE_UNKNOWN）{
Display.isSuspendedState（state））{
setDisplayState（state）;
currentState=state;
}elseif（state==Display.STATE_DOZE_SUSPEND
||oldState==Display.STATE_DOZE_SUSPEND）{
setDisplayState（Display.STATE_DOZE）;
currentState=Display.STATE_DOZE;
//oldstateandnewstateisoff
//Applybrightnesschangesgiventhatweareinanon-suspendedstate.
kangchensetDisplayBrightnessbrightness1="
+brightness）;
setDisplayBrightness（brightness）;
kangchensetDisplayBrightnessbrightness2="
//Enterthefinaldesiredstate,possiblysuspended.
=currentState）{
privatevoidsetDisplayState（intstate）{
setDisplayState（"
+"
id="
+displayId
state="
）"
finalintmode=getPowerModeForState（state）;
SurfaceControl.setDisplayPowerMode（token,mode）;
//到SurfaceControl设置状态
Trace.traceEnd（Trace.TRACE_TAG_POWER）;
privatevoidsetDisplayBrightness（intbrightness）{
mBacklight.setBrightness（brightness）;
//设置亮度
};
DisplayPowerControl设置亮度逻辑（根据VSync信号将亮度慢慢变亮）
上面在DisplayPowerState中仅仅是设置状态，比如刚点亮屏幕这个时候其实设置的brightness为0，我们继续分析DisplayPowerState的updatePowerState函数。
在updatePowerState函数中，当设置亮度时会调用如下代码：
if（!
mPendingScreenOff）{
if（state==Display.STATE_ON||state==Display.STATE_DOZE）{
animateScreenBrightness（brightness,
slowChange?
BRIGHTNESS_RAMP_RATE_SLOW:
BRIGHTNESS_RAMP_RATE_FAST）;
升级会员 