android60 power顯示(亮度等)深入分析(二)DisplayManagerService

1、android6.0 power顯示(亮度等)深入分析(二)DisplayManagerService一、DisplayManagerService注冊(cè)localDisplay的適配層我們先來(lái)看構(gòu)造函數(shù)：cpp view plain copy 在CODE上查看代碼片派生到我的代碼片public DisplayManagerService(Context context) super(context); mContext = context; mHandler = new DisplayManagerHandler(DisplayThread.get().getLooper();/消息處理 mU

2、iHandler = UiThread.getHandler(); mDisplayAdapterListener = new DisplayAdapterListener();/display適配層監(jiān)視器 mSingleDisplayDemoMode = SystemProperties.getBoolean("persist.demo.singledisplay", false); PowerManager pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE); mGlobalDispl

3、ayBrightness = pm.getDefaultScreenBrightnessSetting();/成員變量屏幕亮度 我們?cè)賮?lái)看onStart函數(shù)，publish了一個(gè)BinderService和LocalService，還有發(fā)送了一個(gè)消息。cpp view plain copy 在CODE上查看代碼片派生到我的代碼片Override public void onStart() mHandler.sendEmptyMessage(MSG_REGISTER_DEFAULT_DISPLAY_ADAPTER); publishBinderService(Context.DISPLAY_SE

4、RVICE, new BinderService(), true /*allowIsolated*/); publishLocalService(DisplayManagerInternal.class, new LocalService(); 我們看消息處理，就是調(diào)用了registerDefaultDisplayAdapter函數(shù)：cpp view plain copy 在CODE上查看代碼片派生到我的代碼片Override public void handleMessage(Message msg) switch (msg.what) case MSG_REGISTER_DEFAULT_D

5、ISPLAY_ADAPTER: registerDefaultDisplayAdapter(); break; registerDefaultDisplayAdapter函數(shù)cpp view plain copy 在CODE上查看代碼片派生到我的代碼片private void registerDefaultDisplayAdapter() / Register default display adapter. synchronized (mSyncRoot) registerDisplayAdapterLocked(new LocalDisplayAdapter( mSyncRoot, mCo

6、ntext, mHandler, mDisplayAdapterListener); 再來(lái)看看registerDisplayAdapterLockedcpp view plain copy 在CODE上查看代碼片派生到我的代碼片private void registerDisplayAdapterLocked(DisplayAdapter adapter) mDisplayAdapters.add(adapter); adapter.registerLocked(); 這里就是register了DefaultDisplay的適配層，就是和背光相關(guān)的。在新建LocalDisplayAdapter

7、的時(shí)候我們把mDisplayAdapterListener傳過(guò)去了。二、LocalDisplayAdapter & LocalDisplayDeviceLocalDisplayAdapter構(gòu)造函數(shù)調(diào)用了父類的，而父類也就是保存了變量cpp view plain copy 在CODE上查看代碼片派生到我的代碼片public LocalDisplayAdapter(DisplayManagerService.SyncRoot syncRoot, Context context, Handler handler, Listener listener) super(syncRoot, con

8、text, handler, listener, TAG); 上面又緊跟著調(diào)用了registerLocked函數(shù)cpp view plain copy 在CODE上查看代碼片派生到我的代碼片public void registerLocked() super.registerLocked(); mHotplugReceiver = new HotplugDisplayEventReceiver(getHandler().getLooper(); for (int builtInDisplayId : BUILT_IN_DISPLAY_IDS_TO_SCAN) tryConnectDisplay

9、Locked(builtInDisplayId); tryConnectDisplayLocked函數(shù)，先是看傳入的builtInDisplayId是否支持，一個(gè)是main，一個(gè)是hdmi的。cpp view plain copy 在CODE上查看代碼片派生到我的代碼片private void tryConnectDisplayLocked(int builtInDisplayId) IBinder displayToken = SurfaceControl.getBuiltInDisplay(builtInDisplayId); if (displayToken != null) Surfa

10、ceControl.PhysicalDisplayInfo configs = SurfaceControl.getDisplayConfigs(displayToken); if (configs = null) / There are no valid configs for this device, so we can't use it Slog.w(TAG, "No valid configs found for display device " + builtInDisplayId); return; int activeConfig = SurfaceC

11、ontrol.getActiveConfig(displayToken); if (activeConfig < 0) / There is no active config, and for now we don't have the / policy to set one. Slog.w(TAG, "No active config found for display device " + builtInDisplayId); return; LocalDisplayDevice device = mDevices.get(builtInDisplayId

12、); if (device = null) / Display was added. device = new LocalDisplayDevice(displayToken, builtInDisplayId, configs, activeConfig); mDevices.put(builtInDisplayId, device); sendDisplayDeviceEventLocked(device, DISPLAY_DEVICE_EVENT_ADDED); else if (device.updatePhysicalDisplayInfoLocked(configs, active

13、Config) / Display properties changed. sendDisplayDeviceEventLocked(device, DISPLAY_DEVICE_EVENT_CHANGED); else / The display is no longer available. Ignore the attempt to add it. / If it was connected but has already been disconnected, we'll get a / disconnect event that will remove it from mDev

14、ices. 然后再去查找這個(gè)LocalDisplayDevice，如果是找到了需要更新下configs，沒(méi)找到需要新建一個(gè)LocalDisplayDevice。最后都調(diào)用了sendDisplayDeviceEventLocked函數(shù)。我們?cè)賮?lái)看LocalDisplayDevice，如果傳入的是BUILT_IN_DISPLAY_ID_MAIN就是背光的，我們獲取背光的Light，保存在mBackLight變量。cpp view plain copy 在CODE上查看代碼片派生到我的代碼片public LocalDisplayDevice(IBinder displayToken, int bui

15、ltInDisplayId, SurfaceControl.PhysicalDisplayInfo physicalDisplayInfos, int activeDisplayInfo) super(LocalDisplayAdapter.this, displayToken, UNIQUE_ID_PREFIX + builtInDisplayId); mBuiltInDisplayId = builtInDisplayId; updatePhysicalDisplayInfoLocked(physicalDisplayInfos, activeDisplayInfo); if (mBuil

16、tInDisplayId = SurfaceControl.BUILT_IN_DISPLAY_ID_MAIN) LightsManager lights = LocalServices.getService(LightsManager.class); mBacklight = lights.getLight(LightsManager.LIGHT_ID_BACKLIGHT); else mBacklight = null; 然后上面函數(shù)調(diào)用了sendDisplayDeviceEventLocked函數(shù)，就是調(diào)用了傳入的參數(shù)DisplayAdapterListenercpp view plain

17、 copy 在CODE上查看代碼片派生到我的代碼片protected final void sendDisplayDeviceEventLocked( final DisplayDevice device, final int event) mHandler.post(new Runnable() Override public void run() mListener.onDisplayDeviceEvent(device, event); ); 如果是新建就調(diào)用了handleDisplayDeviceAdded函數(shù)，cpp view plain copy 在CODE上查看代碼片派生到我的代

18、碼片private final class DisplayAdapterListener implements DisplayAdapter.Listener Override public void onDisplayDeviceEvent(DisplayDevice device, int event) switch (event) case DisplayAdapter.DISPLAY_DEVICE_EVENT_ADDED: handleDisplayDeviceAdded(device); break; case DisplayAdapter.DISPLAY_DEVICE_EVENT_

19、CHANGED: handleDisplayDeviceChanged(device); break; case DisplayAdapter.DISPLAY_DEVICE_EVENT_REMOVED: handleDisplayDeviceRemoved(device); break; Override public void onTraversalRequested() synchronized (mSyncRoot) scheduleTraversalLocked(false); 我們先來(lái)看看handleDisplayDeviceAdded，最后將device保存在了mDisplayDe

20、vices中。cpp view plain copy 在CODE上查看代碼片派生到我的代碼片private void handleDisplayDeviceAdded(DisplayDevice device) synchronized (mSyncRoot) handleDisplayDeviceAddedLocked(device); private void handleDisplayDeviceAddedLocked(DisplayDevice device) DisplayDeviceInfo info = device.getDisplayDeviceInfoLocked(); i

21、f (mDisplayDevices.contains(device) Slog.w(TAG, "Attempted to add already added display device: " + info); return; Slog.i(TAG, "Display device added: " + info); device.mDebugLastLoggedDeviceInfo = info; mDisplayDevices.add(device); addLogicalDisplayLocked(device); Runnable work =

22、 updateDisplayStateLocked(device); if (work != null) work.run(); scheduleTraversalLocked(false); 三、設(shè)置背光現(xiàn)在我們?cè)谏掀┛筒皇钦f(shuō)背光的調(diào)制最后是在DisplayManagerService中，是在下面函數(shù)的requestGlobalDisplayStateInternal中調(diào)用的cpp view plain copy 在CODE上查看代碼片派生到我的代碼片public void initPowerManagement(final DisplayPowerCallbacks callbacks,

23、 Handler handler, SensorManager sensorManager) synchronized (mSyncRoot) DisplayBlanker blanker = new DisplayBlanker() Override public void requestDisplayState(int state, int brightness) / The order of operations is important for legacy reasons. if (state = Display.STATE_OFF) requestGlobalDisplayStat

24、eInternal(state, brightness); callbacks.onDisplayStateChange(state); if (state != Display.STATE_OFF) requestGlobalDisplayStateInternal(state, brightness); ; mDisplayPowerController = new DisplayPowerController( mContext, callbacks, handler, sensorManager, blanker); 我們?cè)賮?lái)看看requestGlobalDisplayStateInt

25、ernal函數(shù)：cpp view plain copy 在CODE上查看代碼片派生到我的代碼片private void requestGlobalDisplayStateInternal(int state, int brightness) if (state = Display.STATE_UNKNOWN) state = Display.STATE_ON; if (state = Display.STATE_OFF) brightness = PowerManager.BRIGHTNESS_OFF; else if (brightness < 0) brightness = Powe

26、rManager.BRIGHTNESS_DEFAULT; else if (brightness > PowerManager.BRIGHTNESS_ON) brightness = PowerManager.BRIGHTNESS_ON; synchronized (mTempDisplayStateWorkQueue) try / Update the display state within the lock. / Note that we do not need to schedule traversals here although it / may happen as a si

27、de-effect of displays changing state. synchronized (mSyncRoot) if (mGlobalDisplayState = state && mGlobalDisplayBrightness = brightness) return; / no change Trace.traceBegin(Trace.TRACE_TAG_POWER, "requestGlobalDisplayState(" + Display.stateToString(state) + ", brightness=&quo

28、t; + brightness + ")"); mGlobalDisplayState = state; mGlobalDisplayBrightness = brightness; applyGlobalDisplayStateLocked(mTempDisplayStateWorkQueue); / Setting the display power state can take hundreds of milliseconds / to complete so we defer the most expensive part of the work until / a

29、fter we have exited the critical section to avoid blocking other / threads for a long time. for (int i = 0; i < mTempDisplayStateWorkQueue.size(); i+) mTempDisplayStateWorkQueue.get(i).run(); Trace.traceEnd(Trace.TRACE_TAG_POWER); finally mTempDisplayStateWorkQueue.clear(); 再看看applyGlobalDisplayS

30、tateLocked函數(shù)，最后遍歷device調(diào)用updateDisplayStateLocked函數(shù)cpp view plain copy 在CODE上查看代碼片派生到我的代碼片private void applyGlobalDisplayStateLocked(List<Runnable> workQueue) final int count = mDisplayDevices.size(); for (int i = 0; i < count; i+) DisplayDevice device = mDisplayDevices.get(i); Runnable run

31、nable = updateDisplayStateLocked(device); if (runnable != null) workQueue.add(runnable); updateDisplayStateLocked函數(shù)調(diào)用device的requestDisplayStateLocked返回是Runnable，最后放在workQueue隊(duì)列中cpp view plain copy 在CODE上查看代碼片派生到我的代碼片private Runnable updateDisplayStateLocked(DisplayDevice device) / Blank or unblank t

32、he display immediately to match the state requested / by the display power controller (if known). DisplayDeviceInfo info = device.getDisplayDeviceInfoLocked(); if (info.flags & DisplayDeviceInfo.FLAG_NEVER_BLANK) = 0) return device.requestDisplayStateLocked(mGlobalDisplayState, mGlobalDisplayBri

33、ghtness); return null; 我們?cè)賮?lái)看看LocalDisplayDevice的requestDisplayStateLocked函數(shù)cpp view plain copy 在CODE上查看代碼片派生到我的代碼片public Runnable requestDisplayStateLocked(final int state, final int brightness) / Assume that the brightness is off if the display is being turned off. assert state != Display.STATE_OFF

34、 | brightness = PowerManager.BRIGHTNESS_OFF; final boolean stateChanged = (mState != state); final boolean brightnessChanged = (mBrightness != brightness) && mBacklight != null; if (stateChanged | brightnessChanged) final int displayId = mBuiltInDisplayId; final IBinder token = getDisplayTok

35、enLocked(); final int oldState = mState; if (stateChanged) mState = state;/ 狀態(tài) updateDeviceInfoLocked(); if (brightnessChanged) mBrightness = brightness;/保存亮度 / Defer actually setting the display state until after we have exited / the critical section since it can take hundreds of milliseconds / to

36、complete. return new Runnable() Override public void run() / Exit a suspended state before making any changes. int currentState = oldState; if (Display.isSuspendedState(oldState) | oldState = Display.STATE_UNKNOWN) if (!Display.isSuspendedState(state) setDisplayState(state); currentState = state; el

37、se if (state = Display.STATE_DOZE_SUSPEND | oldState = Display.STATE_DOZE_SUSPEND) setDisplayState(Display.STATE_DOZE); currentState = Display.STATE_DOZE; else return; / old state and new state is off / Apply brightness changes given that we are in a non-suspended state. if (brightnessChanged) setDi

38、splayBrightness(brightness);/設(shè)置亮度 / Enter the final desired state, possibly suspended. if (state != currentState) setDisplayState(state); private void setDisplayState(int state) if (DEBUG) Slog.d(TAG, "setDisplayState(" + "id=" + displayId + ", state=" + Display.stateTo

39、String(state) + ")"); Trace.traceBegin(Trace.TRACE_TAG_POWER, "setDisplayState(" + "id=" + displayId + ", state=" + Display.stateToString(state) + ")"); try final int mode = getPowerModeForState(state); SurfaceControl.setDisplayPowerMode(token, mode)

40、; finally Trace.traceEnd(Trace.TRACE_TAG_POWER); private void setDisplayBrightness(int brightness) if (DEBUG) Slog.d(TAG, "setDisplayBrightness(" + "id=" + displayId + ", brightness=" + brightness + ")"); Trace.traceBegin(Trace.TRACE_TAG_POWER, "setDispla

41、yBrightness(" + "id=" + displayId + ", brightness=" + brightness + ")"); try mBacklight.setBrightness(brightness);/真正的設(shè)置背光 finally Trace.traceEnd(Trace.TRACE_TAG_POWER); ; return null; 上面函數(shù)返回一個(gè)Runnable放在workQueue，在Runnable 中會(huì)調(diào)用mBacklight.setBrightness設(shè)置背光。之前是將Runna

42、ble接口都放在了mTempDisplayStateWorkQueue中，然后遍歷調(diào)用了run函數(shù)。最后就調(diào)用到了LocalDisplayDevice的Runnable接口中設(shè)置背光了。cpp view plain copy 在CODE上查看代碼片派生到我的代碼片synchronized (mSyncRoot) if (mGlobalDisplayState = state && mGlobalDisplayBrightness = brightness) return; / no change Trace.traceBegin(Trace.TRACE_TAG_POWER, &

43、quot;requestGlobalDisplayState(" + Display.stateToString(state) + ", brightness=" + brightness + ")"); mGlobalDisplayState = state; mGlobalDisplayBrightness = brightness; applyGlobalDisplayStateLocked(mTempDisplayStateWorkQueue); / Setting the display power state can take hu

44、ndreds of milliseconds / to complete so we defer the most expensive part of the work until / after we have exited the critical section to avoid blocking other / threads for a long time. for (int i = 0; i < mTempDisplayStateWorkQueue.size(); i+) mTempDisplayStateWorkQueue.get(i).run(); 四、背光hal層我們先

45、來(lái)看看LightsServicecpp view plain copy 在CODE上查看代碼片派生到我的代碼片public class LightsService extends SystemService static final String TAG = "LightsService" static final boolean DEBUG = false; final LightImpl mLights = new LightImplLightsManager.LIGHT_ID_COUNT; private final class LightImpl extends Light private LightImpl(int id) mId = id; Override public void setBrightness(int brightness) setBrightness(brightness, BRIGHTNESS_MODE_USER); Ove