android6.0 PowerManagerService dream分析.doc

android6.0 PowerManagerService dream分析一、Dream关闭首先我们结合打印的log，看看handleSandman函数，log直接加在下面的函数中。当然我们现在说的情况是mWakefulness是dozing状态。cpp view plain copy 在CODE上查看代码片派生到我的代码片private void handleSandman() / runs on handler thread / Handle preconditions. final boolean startDreaming; final int wakefulness; synchronized (mLock) mSandmanScheduled = false; wakefulness = mWakefulness; if (mSandmanSummoned & mDisplayReady) startDreaming = canDreamLocked() | canDozeLocked(); Slog.d(TAG, handleSandman startDreaming: + startDreaming);/这个变量log打印为true mSandmanSummoned = false; else startDreaming = false; / Start dreaming if needed. / We only control the dream on the handler thread, so we dont need to worry about / concurrent attempts to start or stop the dream. final boolean isDreaming; if (mDreamManager != null) / Restart the dream whenever the sandman is summoned. if (startDreaming) mDreamManager.stopDream(false /*immediate*/); mDreamManager.startDream(wakefulness = WAKEFULNESS_DOZING);/调用startStream isDreaming = mDreamManager.isDreaming(); Slog.d(TAG, handleSandman isDreaming: + isDreaming);/返回false else Slog.d(TAG, handleSandman mDreamManager null); isDreaming = false; / Update dream state. synchronized (mLock) / Remember the initial battery level when the dream started. if (startDreaming & isDreaming) mBatteryLevelWhenDreamStarted = mBatteryLevel; if (wakefulness = WAKEFULNESS_DOZING) Slog.i(TAG, Dozing.); else Slog.i(TAG, Dreaming.); / If preconditions changed, wait for the next iteration to determine / whether the dream should continue (or be restarted). if (mSandmanSummoned | mWakefulness != wakefulness) return; / wait for next cycle / Determine whether the dream should continue. if (wakefulness = WAKEFULNESS_DREAMING) Slog.d(TAG, handleSandman WAKEFULNESS_DREAMING); if (isDreaming & canDreamLocked() if (mDreamsBatteryLevelDrainCutoffConfig = 0 & mBatteryLevel mBatteryLevelWhenDreamStarted - mDreamsBatteryLevelDrainCutoffConfig & !isBeingKeptAwakeLocked() / If the user activity timeout expired and the battery appears / to be draining faster than it is charging then stop dreaming / and go to sleep. Slog.i(TAG, Stopping dream because the battery appears to + be draining faster than it is charging. + Battery level when dream started: + mBatteryLevelWhenDreamStarted + %. + Battery level now: + mBatteryLevel + %.); else return; / continue dreaming / Dream has ended or will be stopped. Update the power state. if (isItBedTimeYetLocked() goToSleepNoUpdateLocked(SystemClock.uptimeMillis(), PowerManager.GO_TO_SLEEP_REASON_TIMEOUT, 0, Process.SYSTEM_UID); updatePowerStateLocked(); else wakeUpNoUpdateLocked(SystemClock.uptimeMillis(), android.server.power:DREAM, Process.SYSTEM_UID, mContext.getOpPackageName(), Process.SYSTEM_UID); updatePowerStateLocked(); else if (wakefulness = WAKEFULNESS_DOZING) if (isDreaming) /为false Slog.d(TAG, handleSandman isDreaming = true); return; / continue dozing / Doze has ended or will be stopped. Update the power state. Slog.d(TAG, handleSandman mwakefulness: + mWakefulness);/dozing状态 reallyGoToSleepNoUpdateLocked(SystemClock.uptimeMillis(), Process.SYSTEM_UID); Slog.d(TAG, handleSandman mwakefulness: + mWakefulness);/sleep状态了 updatePowerStateLocked(); Slog.d(TAG, handleSandman wakefulness: + mWakefulness); / Stop dream. if (isDreaming) mDreamManager.stopDream(false /*immediate*/); 看了上面的注释很明显，我们是调用了startdream，但是isDreaming返回是false。明显是没有支持dream。因此power也就直接进入的sleep状态。那我们再来看看这个dream，下面是DreamManagerService的LocalServicecpp view plain copy 在CODE上查看代码片派生到我的代码片private final class LocalService extends DreamManagerInternal Override public void startDream(boolean doze) startDreamInternal(doze); Override public void stopDream(boolean immediate) stopDreamInternal(immediate); Override public boolean isDreaming() return isDreamingInternal(); 我们来看startDreamInternal函数cpp view plain copy 在CODE上查看代码片派生到我的代码片private void startDreamInternal(boolean doze) Slog.d(TAG, startDreamInternal); final int userId = ActivityManager.getCurrentUser(); final ComponentName dream = chooseDreamForUser(doze, userId); if (dream != null) synchronized (mLock) startDreamLocked(dream, false /*isTest*/, doze, userId); else Slog.d(TAG, dream is null);/ 加的打印log 我们在这个函数中加了log，发现dream为null，所以压根美欧调用startDreamLocked函数。cpp view plain copy 在CODE上查看代码片派生到我的代码片private ComponentName chooseDreamForUser(boolean doze, int userId) if (doze) ComponentName dozeComponent = getDozeComponent(userId); return validateDream(dozeComponent) ? dozeComponent : null; ComponentName dreams = getDreamComponentsForUser(userId); return dreams != null & dreams.length != 0 ? dreams0 : null; chooseDreamForUser返回为null，是因为getDozeComponent返回为null。我们再看getDozeComponent函数：cpp view plain copy 在CODE上查看代码片派生到我的代码片private ComponentName getDozeComponent(int userId) String name = Build.IS_DEBUGGABLE ? SystemProperties.get(ponent) : null; if (TextUtils.isEmpty(name) name = mContext.getResources().getString( ernal.R.string.config_dozeComponent); boolean enabled = Settings.Secure.getIntForUser(mContext.getContentResolver(), Settings.Secure.DOZE_ENABLED, 1, userId) != 0; return TextUtils.isEmpty(name) | !enabled ? null : ComponentName.unflattenFromString(name); 上面这个变量name是null，导致返回null。还是系统没有支持dream的原因。二、DreamService虽然我们系统不支持，我们也看下代码，先看下startDreamLocked函数cpp view plain copy 在CODE上查看代码片派生到我的代码片private void startDreamLocked(final ComponentName name, final boolean isTest, final boolean canDoze, final int userId) if (Objects.equal(mCurrentDreamName, name) & mCurrentDreamIsTest = isTest & mCurrentDreamCanDoze = canDoze & mCurrentDreamUserId = userId) return; stopDreamLocked(true /*immediate*/); Slog.i(TAG, Entering dreamland.); final Binder newToken = new Binder(); mCurrentDreamToken = newToken; mCurrentDreamName = name; mCurrentDreamIsTest = isTest; mCurrentDreamCanDoze = canDoze; mCurrentDreamUserId = userId; mHandler.post(new Runnable() Override public void run() mController.startDream(newToken, name, isTest, canDoze, userId); ); 最终是调用了mController.startDream函数，再来看DreamController类的startDream函数cpp view plain copy 在CODE上查看代码片派生到我的代码片public void startDream(Binder token, ComponentName name, boolean isTest, boolean canDoze, int userId) stopDream(true /*immediate*/); Trace.traceBegin(Trace.TRACE_TAG_POWER, startDream); try / Close the tification shade. Dont need to send to all, but better to be explicit. mContext.sendBroadcastAsUser(mCloseNotificationShadeIntent, UserHandle.ALL); mCurrentDream = new DreamRecord(token, name, isTest, canDoze, userId); mDreamStartTime = SystemClock.elapsedRealtime(); MetricsLogger.visible(mContext, mCurrentDream.mCanDoze ? MetricsLogger.DOZING : MetricsLogger.DREAMING); try mIWindowManager.addWindowToken(token, WindowManager.LayoutParams.TYPE_DREAM); catch (RemoteException ex) Slog.e(TAG, Unable to add window token for dream., ex); stopDream(true /*immediate*/); return; Intent intent = new Intent(DreamService.SERVICE_INTERFACE); intent.setComponent(name); intent.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS); try if (!mContext.bindServiceAsUser(intent, mCurrentDream,/开启Service Context.BIND_AUTO_CREATE | Context.BIND_FOREGROUND_SERVICE, new UserHandle(userId) Slog.e(TAG, Unable to bind dream service: + intent); stopDream(true /*immediate*/); return; catch (SecurityException ex) Slog.e(TAG, Unable to bind dream service: + intent, ex); stopDream(true /*immediate*/); return; mCurrentDream.mBound = true; mHandler.postDelayed(mStopUnconnectedDreamRunnable, DREAM_CONNECTION_TIMEOUT);/出错处理 finally Trace.traceEnd(Trace.TRACE_TAG_POWER); 然后bindService了DreamService，我们来看这个Service的onBind接口。cpp view plain copy 在CODE上查看代码片派生到我的代码片public final IBinder onBind(Intent intent) if (mDebug) Slog.v(TAG, onBind() intent = + intent); return new DreamServiceWrapper(); DreamServiceWrapper 如下，就是binder接口。用来binder通信cpp view plain copy 在CODE上查看代码片派生到我的代码片private final class DreamServiceWrapper extends IDreamService.Stub Override public void attach(final IBinder windowToken, final boolean canDoze) mHandler.post(new Runnable() Override public void run() DreamService.this.attach(windowToken, canDoze); ); Override public void detach() mHandler.post(new Runnable() Override public void run() DreamService.this.detach(); ); Override public void wakeUp() mHandler.post(new Runnable() Override public void run() DreamService.this.wakeUp(true /*fromSystem*/); ); 我们再来看DreamRecord ，就是在DreamController调用bindService时候作为ServiceConnection cpp view ain copy 在CODE上查看代码片派生到我的代码片private final class DreamRecord implements DeathRecipient, ServiceConnection . / May be ca