http://blog.youkuaiyun.com/kc58236582/article/details/54612777
亮屏、灭屏流程整个流程涉及的模块比较多,包括PowerManagerService、DisplayPowerControl、WMS、AMS。因此在分析完WMS之后,我们把这块也分析下。
DisplayPowerControl
我们知道灭屏流程的发起是在PowerManagerService中,会通过updatePowerState函数调用updateDisplayPowerStateLocked函数,再调用DisplayPowerControl的requestPowerState函数,到DisplayPowerControl中。DisplayPowerControl中后面会调用updatePowerState函数,我们也主要从这个函数开始分析:
updatePowerState会根据PowerManagerService传过来的显示状态,然后调用animateScreenStateChange函数。
- animateScreenStateChange(state, performScreenOffTransition);
下面我们先来看animateScreenStateChange函数:
- private void animateScreenStateChange(int target, boolean performScreenOffTransition) {
- // If there is already an animation in progress, don't interfere with it.
- if (mColorFadeOnAnimator.isStarted()
- || mColorFadeOffAnimator.isStarted()) {
- return;
- }
- // If we were in the process of turning off the screen but didn't quite
- // finish. Then finish up now to prevent a jarring transition back
- // to screen on if we skipped blocking screen on as usual.
- if (mPendingScreenOff && target != Display.STATE_OFF) {
- setScreenState(Display.STATE_OFF);
- mPendingScreenOff = false;
- mPowerState.dismissColorFadeResources();
- }
- if (target == Display.STATE_ON) {//亮屏处理
- // Want screen on. The contents of the screen may not yet
- // be visible if the color fade has not been dismissed because
- // its last frame of animation is solid black.
- if (!setScreenState(Display.STATE_ON)) {
- return; // screen on blocked
- }
- if (USE_COLOR_FADE_ON_ANIMATION && mPowerRequest.isBrightOrDim()) {//亮屏动画
- // Perform screen on animation.
- if (mPowerState.getColorFadeLevel() == 1.0f) {
- mPowerState.dismissColorFade();
- } else if (mPowerState.prepareColorFade(mContext,
- mColorFadeFadesConfig ?
- ColorFade.MODE_FADE :
- ColorFade.MODE_WARM_UP)) {
- mColorFadeOnAnimator.start();
- } else {
- mColorFadeOnAnimator.end();
- }
- } else {//跳过亮屏动画
- // Skip screen on animation.
- mPowerState.setColorFadeLevel(1.0f);
- mPowerState.dismissColorFade();
- }
- } else if (target == Display.STATE_DOZE) {
- // Want screen dozing.
- // Wait for brightness animation to complete beforehand when entering doze
- // from screen on to prevent a perceptible jump because brightness may operate
- // differently when the display is configured for dozing.
- ......
- } else if (target == Display.STATE_DOZE_SUSPEND) {
- // Want screen dozing and suspended.
- // Wait for brightness animation to complete beforehand unless already
- // suspended because we may not be able to change it after suspension.
- ......
- } else {//灭屏处理
- // Want screen off.
- mPendingScreenOff = true;
- if (mPowerState.getColorFadeLevel() == 0.0f) {//灭屏动画结束
- // Turn the screen off.
- // A black surface is already hiding the contents of the screen.
- setScreenState(Display.STATE_OFF);
- mPendingScreenOff = false;
- mPowerState.dismissColorFadeResources();
- } else if (performScreenOffTransition
- && mPowerState.prepareColorFade(mContext,
- mColorFadeFadesConfig ?
- ColorFade.MODE_FADE : ColorFade.MODE_COOL_DOWN)
- && mPowerState.getScreenState() != Display.STATE_OFF) {
- // Perform the screen off animation.
- mColorFadeOffAnimator.start();//开启灭屏动画
- } else {
- // Skip the screen off animation and add a black surface to hide the
- // contents of the screen.
- mColorFadeOffAnimator.end();//关闭灭屏动画
- }
- }
- }
animateScreenStateChange在亮屏的处理的时候,先会调用setScreenState(Display.STATE_ON),然后根据USE_COLOR_FADE_ON_ANIMATION 判断是否要开启亮屏动画,这里我们是没有设置的。因此直接跳过亮屏动画。灭屏的处理的话,会有一个灭屏动画(也是注册一个VSync信号回调函数处理的,这里我们不分析了),当动画结束后,直接就调用setScreenState(Display.STATE_OFF)结束。
我们再来看看setScreenState函数
- private boolean setScreenState(int state) {
- if (mPowerState.getScreenState() != state) {
- final boolean wasOn = (mPowerState.getScreenState() != Display.STATE_OFF);
- mPowerState.setScreenState(state);
- ......
- }
- // Tell the window manager policy when the screen is turned off or on unless it's due
- // to the proximity sensor. We temporarily block turning the screen on until the
- // window manager is ready by leaving a black surface covering the screen.
- // This surface is essentially the final state of the color fade animation and
- // it is only removed once the window manager tells us that the activity has
- // finished drawing underneath.
- final boolean isOff = (state == Display.STATE_OFF);
- if (isOff && mReportedScreenStateToPolicy != REPORTED_TO_POLICY_SCREEN_OFF
- && !mScreenOffBecauseOfProximity) {
- mReportedScreenStateToPolicy = REPORTED_TO_POLICY_SCREEN_OFF;
- unblockScreenOn();
- mWindowManagerPolicy.screenTurnedOff();//调用PhoneWindowManager的screenTurnedOff
- } else if (!isOff && mReportedScreenStateToPolicy == REPORTED_TO_POLICY_SCREEN_OFF) {
- mReportedScreenStateToPolicy = REPORTED_TO_POLICY_SCREEN_TURNING_ON;
- if (mPowerState.getColorFadeLevel() == 0.0f) {
- blockScreenOn();
- } else {
- unblockScreenOn();
- }
- mWindowManagerPolicy.screenTurningOn(mPendingScreenOnUnblocker);//调用PhoneWindowManager的screenTurningOn函数
- }
- // Return true if the screen isn't blocked.
- return mPendingScreenOnUnblocker == null;
- }
setScreenState函数,先是调用了DisplayPowerState的setScreenState函数,然后根据屏幕是灭屏还是亮屏调用PhoneWindowManager的相关函数。
PhoneWindowManager的screenTurnedOff和screenTurningOn函数
PhoneWindowManager的screenTurnedOff函数主要是通知kerguard,屏幕灭屏了。
- @Override
- public void screenTurnedOff() {
- if (DEBUG_WAKEUP) Slog.i(TAG, "Screen turned off...");
- updateScreenOffSleepToken(true);
- synchronized (mLock) {
- mScreenOnEarly = false;
- mScreenOnFully = false;
- mKeyguardDrawComplete = false;
- mWindowManagerDrawComplete = false;
- mScreenOnListener = null;
- updateOrientationListenerLp();
- if (mKeyguardDelegate != null) {
- mKeyguardDelegate.onScreenTurnedOff();
- }
- }
- }
我们再来看PhoneWindowManager的screenTurningOn函数。当有keyguard时,我们会先发一个延时的MSG_KEYGUARD_DRAWN_TIMEOUT信号,并且会调用keyguard的onScreenTurningOn函数,当完成会调用mKeyguardDrawnCallback回调函数。我们这里还要注意下有一个屏幕点亮后的回调。
- @Override
- public void screenTurningOn(final ScreenOnListener screenOnListener) {
- if (DEBUG_WAKEUP) Slog.i(TAG, "Screen turning on...");
- updateScreenOffSleepToken(false);
- synchronized (mLock) {
- mScreenOnEarly = true;
- mScreenOnFully = false;
- mKeyguardDrawComplete = false;
- mWindowManagerDrawComplete = false;
- mScreenOnListener = screenOnListener;//屏幕点亮后的回调
- if (mKeyguardDelegate != null) {
- if (DEBUG_WAKEUP) Slog.d(TAG,
- "send delay message MSG_KEYGUARD_DRAWN_TIMEOUT");
- mHandler.removeMessages(MSG_KEYGUARD_DRAWN_TIMEOUT);
- mHandler.sendEmptyMessageDelayed(MSG_KEYGUARD_DRAWN_TIMEOUT, 1000);
- mKeyguardDelegate.onScreenTurningOn(mKeyguardDrawnCallback);
- } else {
- if (DEBUG_WAKEUP) Slog.d(TAG,
- "null mKeyguardDelegate: setting mKeyguardDrawComplete.");
- finishKeyguardDrawn();
- }
- }
- }
我们先看下mKeyguardDrawnCallback 回调,就是发送MSG_KEYGUARD_DRAWN_COMPLETE(keyguard绘制完的消息)
- final DrawnListener mKeyguardDrawnCallback = new DrawnListener() {
- @Override
- public void onDrawn() {
- if (DEBUG_WAKEUP) Slog.d(TAG, "mKeyguardDelegate.ShowListener.onDrawn.");
- mHandler.sendEmptyMessage(MSG_KEYGUARD_DRAWN_COMPLETE);
- }
- };
我们再来看看MSG_KEYGUARD_DRAWN_COMPLETE以及MSG_KEYGUARD_DRAWN_TIMEOUT信号的处理,都会调用finishKeyguardDrawn函数。
- case MSG_KEYGUARD_DRAWN_COMPLETE:
- if (DEBUG_WAKEUP) Slog.w(TAG, "Setting mKeyguardDrawComplete");
- finishKeyguardDrawn();
- break;
- case MSG_KEYGUARD_DRAWN_TIMEOUT:
- Slog.w(TAG, "Keyguard drawn timeout. Setting mKeyguardDrawComplete");
- finishKeyguardDrawn();
- break;
- private void finishKeyguardDrawn() {
- synchronized (mLock) {
- if (!mScreenOnEarly || mKeyguardDrawComplete) {
- return; // We are not awake yet or we have already informed of this event.
- }
- mKeyguardDrawComplete = true;
- if (mKeyguardDelegate != null) {
- mHandler.removeMessages(MSG_KEYGUARD_DRAWN_TIMEOUT);
- }
- mWindowManagerDrawComplete = false;
- }
- // ... eventually calls finishWindowsDrawn which will finalize our screen turn on
- // as well as enabling the orientation change logic/sensor.
- mWindowManagerInternal.waitForAllWindowsDrawn(mWindowManagerDrawCallback,
- WAITING_FOR_DRAWN_TIMEOUT);
- }
最后我们再看看WMS的waitForAllWindowsDrawn函数,以及两个参数mWindowManagerDrawCallback和一个WAITING_FOR_DRAWN_TIMEOUT(1秒)。
WMS的waitForAllWindowsDrawn函数
我们先来看看WMS的waitForAllWindowsDrawn函数,会把传进来的回调保存在mWaitingForDrawnCallback 。然后遍历所有的windows,把需要显示或者已经显示的窗口全部加入到mWaitingForDrawn,然后调用requestTraversalLocked这个函数我们之前分析过,就是发送一个消息,重新刷新UI布局。然后我们继续分析这个函数,如果mWaitingForDrawn为空,代表没啥显示的直接调用回调函数,如果mWaitingForDrawn有要显示的窗口,就要会先发送一个WAITING_FOR_DRAWN_TIMEOUT,这个timeout之前传进来的是1秒。然后调用checkDrawnWindowsLocked函数。
- @Override
- public void waitForAllWindowsDrawn(Runnable callback, long timeout) {
- synchronized (mWindowMap) {
- mWaitingForDrawnCallback = callback;//回调保存在mWaitingForDrawnCallback
- final WindowList windows = getDefaultWindowListLocked();
- for (int winNdx = windows.size() - 1; winNdx >= 0; --winNdx) {
- final WindowState win = windows.get(winNdx);
- final boolean isForceHiding = mPolicy.isForceHiding(win.mAttrs);
- Slog.i(TAG,"In the function waitForAllWindowsDrawn");
- if (win.isVisibleLw()
- && (win.mAppToken != null || isForceHiding)) {
- Slog.i(TAG,"In the function win.isVisibleLw()");
- win.mWinAnimator.mDrawState = WindowStateAnimator.DRAW_PENDING;
- // Force add to mResizingWindows.
- win.mLastContentInsets.set(-1, -1, -1, -1);
- mWaitingForDrawn.add(win);
- // No need to wait for the windows below Keyguard.
- if (isForceHiding) {
- break;
- }
- }
- }
- requestTraversalLocked();
- }
- mH.removeMessages(H.WAITING_FOR_DRAWN_TIMEOUT);
- if (mWaitingForDrawn.isEmpty()) {
- callback.run();
- Slog.i(TAG,"In the function mWaitingForDrawn.isEmpty()");
- } else {
- mH.sendEmptyMessageDelayed(H.WAITING_FOR_DRAWN_TIMEOUT, timeout);
- checkDrawnWindowsLocked();
- Slog.i(TAG,"In the function checkDrawnWindowsLocked()");
- }
- }
我们先来看下checkDrawnWindowsLocked函数,这个函数。遍历之前加入的mWaitingForDrawn(要显示的窗口),这个时候我们把已经去除的,不需要显示的,没有surface的窗口从mWaitingForDrawn去除,还有已经绘制好的也去除。然后再当mWaitingForDrawn为空时,就发送ALL_WINDOWS_DRAWN消息。
- void checkDrawnWindowsLocked() {
- if (mWaitingForDrawn.isEmpty() || mWaitingForDrawnCallback == null) {
- return;
- }
- for (int j = mWaitingForDrawn.size() - 1; j >= 0; j--) {
- WindowState win = mWaitingForDrawn.get(j);
- if (win.mRemoved || !win.mHasSurface || !win.mPolicyVisibility) {
- // Window has been removed or hidden; no draw will now happen, so stop waiting.
- if (DEBUG_SCREEN_ON) Slog.w(TAG, "Aborted waiting for drawn: " + win);
- mWaitingForDrawn.remove(win);
- } else if (win.hasDrawnLw()) {
- // Window is now drawn (and shown).
- if (DEBUG_SCREEN_ON) Slog.d(TAG, "Window drawn win=" + win);
- mWaitingForDrawn.remove(win);
- }
- }
- if (mWaitingForDrawn.isEmpty()) {
- if (DEBUG_SCREEN_ON) Slog.d(TAG, "All windows drawn!");
- mH.removeMessages(H.WAITING_FOR_DRAWN_TIMEOUT);
- mH.sendEmptyMessage(H.ALL_WINDOWS_DRAWN);
- }
- }
ALL_WINDOWS_DRAWN消息的处理就是清除mWaitingForDrawnCallback ,然后调用回调。
- case ALL_WINDOWS_DRAWN: {
- Runnable callback;
- synchronized (mWindowMap) {
- callback = mWaitingForDrawnCallback;
- mWaitingForDrawnCallback = null;
- }
- if (callback != null) {
- callback.run();
- }
- }
还有当我们调用waitForAllWindowsDrawn一般都是有需要显示的窗口,但是我们直接调用checkDrawnWindowsLocked函数,发现有的窗口还没绘制完成。那么我们就要等,会在刷新的核心函数中performLayoutAndPlaceSurfacesLockedInner有如下代码,这个时候如果之前还没绘制完成的窗口,绘制好了。会再调用checkDrawnWindowsLocked函数,如果mWaitingForDrawn中的窗口绘制好了,会在mWaitingForDrawn中去除这个窗口。然后mWaitingForDrawn为空了,之后会发送ALL_WINDOWS_DRAWN消息,还调用mWaitingForDrawnCallback回调函数。
- if (mWaitingForDrawnCallback != null ||
- (mInnerFields.mOrientationChangeComplete && !defaultDisplay.layoutNeeded &&
- !mInnerFields.mUpdateRotation)) {
- checkDrawnWindowsLocked();
- }
当然如果我们之前没有把mWaitingForDrawn中的窗口清空,最后在WAITING_FOR_DRAWN_TIMEOUT(这里是1秒)时间到了也会调用回调的。
- case WAITING_FOR_DRAWN_TIMEOUT: {
- Runnable callback = null;
- synchronized (mWindowMap) {
- Slog.w(TAG, "Timeout waiting for drawn: undrawn=" + mWaitingForDrawn);
- mWaitingForDrawn.clear();
- callback = mWaitingForDrawnCallback;
- mWaitingForDrawnCallback = null;
- }
- if (callback != null) {
- callback.run();
- }
- break;
- }
PhoneWindowManager窗口绘制完成的回调函数
那下面我们就要继续看PhoneWindowManager中窗口绘制完成之后的回调函数。代码如下就是发送了一个消息。
- final Runnable mWindowManagerDrawCallback = new Runnable() {
- @Override
- public void run() {
- if (DEBUG_WAKEUP) Slog.i(TAG, "All windows ready for display!");
- mHandler.sendEmptyMessage(MSG_WINDOW_MANAGER_DRAWN_COMPLETE);
- }
- };
我们来看这个消息的处理
- case MSG_WINDOW_MANAGER_DRAWN_COMPLETE:
- if (DEBUG_WAKEUP) Slog.w(TAG, "Setting mWindowManagerDrawComplete");
- finishWindowsDrawn();
- break;
finishWindowsDrawn就是把mWindowManagerDrawComplete 置为true,然后调用finishScreenTurningOn函数。
- private void finishWindowsDrawn() {
- synchronized (mLock) {
- if (!mScreenOnEarly || mWindowManagerDrawComplete) {
- return; // Screen is not turned on or we did already handle this case earlier.
- }
- mWindowManagerDrawComplete = true;
- }
- finishScreenTurningOn();
- }
finishScreenTurningOn函数调用了之前在DisplayPowerControl中调用screenTurningOn传入的回调,然后再调用WMS的enableScreenIfNeeded函数。
- private void finishScreenTurningOn() {
- synchronized (mLock) {
- updateOrientationListenerLp();
- }
- final ScreenOnListener listener;
- final boolean enableScreen;
- synchronized (mLock) {
- if (mScreenOnFully || !mScreenOnEarly || !mWindowManagerDrawComplete
- || (mAwake && !mKeyguardDrawComplete)) {
- return; // spurious or not ready yet
- }
- listener = mScreenOnListener;
- mScreenOnListener = null;
- mScreenOnFully = true;
- ......
- }
- if (listener != null) {
- listener.onScreenOn();
- }
- if (enableScreen) {
- try {
- mWindowManager.enableScreenIfNeeded();
- } catch (RemoteException unhandled) {
- }
- }
- }
我们先分析下WMS的enableScreenIfNeeded函数,然后再看DisplayPowerControl的回调onScreenOn函数。
WMS的enableScreenIfNeeded函数
WMS的enableScreenIfNeeded函数就是调用了enableScreenIfNeededLocked函数
- @Override
- public void enableScreenIfNeeded() {
- synchronized (mWindowMap) {
- enableScreenIfNeededLocked();
- }
- }
enableScreenIfNeededLocked这个函数仅仅是保证mDisplayEnabled为true,如果为true直接结束。
- void enableScreenIfNeededLocked() {
- if (mDisplayEnabled) {
- return;
- }
- if (!mSystemBooted && !mShowingBootMessages) {
- return;
- }
- mH.sendEmptyMessage(H.ENABLE_SCREEN);
- }
mDisplayEnabled不为true,发送ENABLE_SCREEN消息
- case ENABLE_SCREEN: {
- performEnableScreen();
- break;
performEnableScreen函数会让SurfaceFlinger去停止开机动画等,也会把mDisplayEnabled置为true。当然performEnableScreen在开机的时候会AMS中调用WMS的enableScreenAfterBoot函数来调用performEnableScreen函数。这个我们在博客http://blog.youkuaiyun.com/kc58236582/article/details/52921978分析过了。
- public void performEnableScreen() {
- synchronized(mWindowMap) {
- if (mDisplayEnabled) {
- return;
- }
- if (!mSystemBooted && !mShowingBootMessages) {
- return;
- }
- // Don't enable the screen until all existing windows have been drawn.
- if (!mForceDisplayEnabled && checkWaitingForWindowsLocked()) {
- return;
- }
- if (!mBootAnimationStopped) {
- // Do this one time.
- try {//停止开机动画
- IBinder surfaceFlinger = ServiceManager.getService("SurfaceFlinger");
- if (surfaceFlinger != null) {
- //Slog.i(TAG, "******* TELLING SURFACE FLINGER WE ARE BOOTED!");
- Parcel data = Parcel.obtain();
- data.writeInterfaceToken("android.ui.ISurfaceComposer");
- surfaceFlinger.transact(IBinder.FIRST_CALL_TRANSACTION, // BOOT_FINISHED
- data, null, 0);
- data.recycle();
- }
- } catch (RemoteException ex) {
- Slog.e(TAG, "Boot completed: SurfaceFlinger is dead!");
- }
- mBootAnimationStopped = true;
- }
- if (!mForceDisplayEnabled && !checkBootAnimationCompleteLocked()) {
- if (DEBUG_BOOT) Slog.i(TAG, "performEnableScreen: Waiting for anim complete");
- return;
- }
- mDisplayEnabled = true;//置为true
- if (DEBUG_SCREEN_ON || DEBUG_BOOT) Slog.i(TAG, "******************** ENABLING SCREEN!");
- // Enable input dispatch.
- mInputMonitor.setEventDispatchingLw(mEventDispatchingEnabled);
- }
- try {
- mActivityManager.bootAnimationComplete();
- } catch (RemoteException e) {
- }
- mPolicy.enableScreenAfterBoot();
- // Make sure the last requested orientation has been applied.
- updateRotationUnchecked(false, false);
- }
窗口绘制完成后调用DisplayPowerControl中的回调
当WMS窗口绘制完成后,会在PhoneWindowManager中的finishScreenTurningOn函数调用DisplayPowerControl的回调函数。最后我们再来看看DisplayPowerControl中的回调的onScreenOn函数。只是发送了一个MSG_SCREEN_ON_UNBLOCKED消息。
- private final class ScreenOnUnblocker implements WindowManagerPolicy.ScreenOnListener {
- @Override
- public void onScreenOn() {
- Message msg = mHandler.obtainMessage(MSG_SCREEN_ON_UNBLOCKED, this);
- msg.setAsynchronous(true);
- mHandler.sendMessage(msg);
- }
- }
MSG_SCREEN_ON_UNBLOCKED的处理先是调用了unblockScreenOn函数,然后再调用updatePowerState更新状态。
- case MSG_SCREEN_ON_UNBLOCKED:
- if (mPendingScreenOnUnblocker == msg.obj) {
- unblockScreenOn();
- updatePowerState();
- }
- break;
unblockScreenOn函数,只是打印下从调用screenTurningOn开始,到窗口绘制完成在PhoneWindowManager中回调这个函数的时间差打印。
- private void unblockScreenOn() {
- if (mPendingScreenOnUnblocker != null) {
- mPendingScreenOnUnblocker = null;
- long delay = SystemClock.elapsedRealtime() - mScreenOnBlockStartRealTime;
- Slog.i(TAG, "Unblocked screen on after " + delay + " ms");
- Trace.asyncTraceEnd(Trace.TRACE_TAG_POWER, SCREEN_ON_BLOCKED_TRACE_NAME, 0);
- }
- }