frameworks 之 AMS与ActivityThread交互
- 1. 类关系
- 2. 流程
- 2.1 AMS流程
- 2.1 ActivityThread流程
- 3. 堆栈
讲解AMS 如何和 ActivityThread 生命周期调用流程
涉及到的类如下
- frameworks/base/core/java/android/app/servertransaction/ResumeActivityItem.java
- frameworks/base/core/java/android/app/Activity.java
- frameworks/base/core/java/android/app/ActivityThread.java
- frameworks/base/services/core/java/com/android/server/wm/ActivityTaskSupervisor.java
- frameworks/base/core/java/android/app/servertransaction/ClientTransaction.java
- frameworks/base/core/java/android/app/ClientTransactionHandler.java
1. 类关系
- TransactionItem** 以及其子类都为 具体执行的对象
- ClientTransaction 作为 AMS 和 ActivityThread 交互的对象,里面包含 ActivityLifecycleItem 的 mLifecycleStateRequest 和 List<ClientTransactionItem> mActivityCallbacks 成员变量。
- ActivityThread 继承自 ClientTransactionHandler,里面包含了内部类 ApplicationThread 该类实现了 IApplicationThread.AIDL 方法。当服务端调用该AIDL方法执行app逻辑, 该内容类又会调用 ActivityThread 下的方法,部分方法实现 在 ClientTransactionHandler 中
@Overridepublic void scheduleTransaction(ClientTransaction transaction) throws RemoteException {//在父类 ClientTransactionHandlerActivityThread.this.scheduleTransaction(transaction);}
2. 流程
2.1 AMS流程
startActivity 最后会调用到 realStartActivityLocked 方法。
- 构建 ClientTransaction 负责传递给 界面端调用,第一个参数为客户端IApplicationThread AIDL传递给变量mClient
- 通过 addCallback添加对应的执行对象
- // 将 生命周期要执行的状态 lifecycleItem 传递给对应的 mLifecycleStateRequest 属性
- 调用 scheduleTransaction 方法,里面会调用 clientTransaction 的schedule 方法,schedule方法又会调用 mClient 的scheduleTransaction,这时候调用到客户端
// 构建 ClientTransaction 负责传递给 界面端调用,第一个参数为客户端IApplicationThread AIDL传递给变量mClientfinal ClientTransaction clientTransaction = ClientTransaction.obtain(proc.getThread(), r.appToken);final boolean isTransitionForward = r.isTransitionForward();// 添加对应执行的LaunchActivityItem对象,用于给客户端执行clientTransaction.addCallback(LaunchActivityItem.obtain(new Intent(r.intent),System.identityHashCode(r), r.info,// TODO: Have this take the merged configuration instead of separate global// and override configs.mergedConfiguration.getGlobalConfiguration(),mergedConfiguration.getOverrideConfiguration(), r.compat,r.getFilteredReferrer(r.launchedFromPackage), task.voiceInteractor,proc.getReportedProcState(), r.getSavedState(), r.getPersistentSavedState(),results, newIntents, r.takeOptions(), isTransitionForward,proc.createProfilerInfoIfNeeded(), r.assistToken, activityClientController,r.createFixedRotationAdjustmentsIfNeeded(), r.shareableActivityToken,r.getLaunchedFromBubble()));// Set desired final state.final ActivityLifecycleItem lifecycleItem;// 设置对应的状态if (andResume) {lifecycleItem = ResumeActivityItem.obtain(isTransitionForward);} else {lifecycleItem = PauseActivityItem.obtain();}// 将 生命周期要执行的状态 lifecycleItem 传递给对应的 mLifecycleStateRequest 属性clientTransaction.setLifecycleStateRequest(lifecycleItem);// Schedule transaction.// 里面会调用 clientTransaction 的schedule 方法,schedule方法又会调用 mClient 的scheduleTransactionmService.getLifecycleManager().scheduleTransaction(clientTransaction);
void scheduleTransaction(ClientTransaction transaction) throws RemoteException {final IApplicationThread client = transaction.getClient();transaction.schedule();if (!(client instanceof Binder)) {// If client is not an instance of Binder - it's a remote call and at this point it is// safe to recycle the object. All objects used for local calls will be recycled after// the transaction is executed on client in ActivityThread.transaction.recycle();}}public void schedule() throws RemoteException {mClient.scheduleTransaction(this);}
2.1 ActivityThread流程
调用了 scheduleTransaction aidl 方法后,就到了 客户端ApplicationThread 执行的方法, 该方法又会调用 scheduleTransaction,该方法在 ClientTransactionHandler 中
private class ApplicationThread extends IApplicationThread.Stub {@Overridepublic void scheduleTransaction(ClientTransaction transaction) throws RemoteException {// 在父类 ClientTransactionHandlerActivityThread.this.scheduleTransaction(transaction);}
}
查看 ClientTransactionHandler 的 scheduleTransaction 方法。
- 执行对应的 preExecute并将对应的 ActvityThread传递进去
- 发送了对应 handler 消息,该消息的接收在 ActvityThread
void scheduleTransaction(ClientTransaction transaction) {// 执行对应的 preExecute并将对应的 ActvityThread传递进去transaction.preExecute(this);// 发送消息sendMessage(ActivityThread.H.EXECUTE_TRANSACTION, transaction);}
收到消息后,执行对应的 TransactionExecutor 的 execute 方法,并和咨询
case EXECUTE_TRANSACTION:// 该回调在其父类触发 scheduleTransaction 发送消息final ClientTransaction transaction = (ClientTransaction) msg.obj;mTransactionExecutor.execute(transaction);if (isSystem()) {// Client transactions inside system process are recycled on the client side// instead of ClientLifecycleManager to avoid being cleared before this// message is handled.transaction.recycle();}// TODO(lifecycler): Recycle locally scheduled transactions.break;
该方法 会通过 executeCallbacks, executeLifecycleState 依次调用 服务端赋值给对应的执行实现类 。
public void execute(ClientTransaction transaction) {...executeCallbacks(transaction);// 调用对应的生命周期回调executeLifecycleState(transaction);mPendingActions.clear();if (DEBUG_RESOLVER) Slog.d(TAG, tId(transaction) + "End resolving transaction");}
onResume 对应的是 executeLifecycleState 方法,该方法会又会调用 对应 实现类的 **execute 和 postExecute ** 方法。从服务端知道 onResume 实现类为 ResumeActivityItem。
private void executeLifecycleState(ClientTransaction transaction) {....// Execute the final transition with proper parameters.lifecycleItem.execute(mTransactionHandler, token, mPendingActions);lifecycleItem.postExecute(mTransactionHandler, token, mPendingActions);}
ResumeActivityItem 的 execute 会执行 ActivityThread 的 handleResumeActivity 方法,开始进行对应 activity的 onResume 回调
@Overridepublic void execute(ClientTransactionHandler client, ActivityClientRecord r,PendingTransactionActions pendingActions) {Trace.traceBegin(TRACE_TAG_ACTIVITY_MANAGER, "activityResume");// 执行 ActivityThread 的 handleResumeActivityclient.handleResumeActivity(r, true /* finalStateRequest */, mIsForward,"RESUME_ACTIVITY");Trace.traceEnd(TRACE_TAG_ACTIVITY_MANAGER);}
handleResumeActivity 方法又会调用对应的 performResumeActivity方法,这样就开始了 onResume回调的触发
@Overridepublic void handleResumeActivity(ActivityClientRecord r, boolean finalStateRequest,boolean isForward, String reason) {// If we are getting ready to gc after going to the background, well// we are back active so skip it.unscheduleGcIdler();mSomeActivitiesChanged = true;// TODO Push resumeArgs into the activity for consideration// skip below steps for double-resume and r.mFinish = true case.if (!performResumeActivity(r, finalStateRequest, reason)) {return;}...}
3. 堆栈
追踪Activity 生命周期调用 如 onResume 可以在 Activity 添加堆栈
01-16 06:26:45.387 1265 1265 E traceResume: traceResume
01-16 06:26:45.387 1265 1265 E traceResume: java.lang.NullPointerException
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.Activity.onResume(Activity.java:1951)
01-16 06:26:45.387 1265 1265 E traceResume: at com.android.launcher3.BaseActivity.onResume(BaseActivity.java:182)
01-16 06:26:45.387 1265 1265 E traceResume: at com.android.launcher3.BaseDraggingActivity.onResume(BaseDraggingActivity.java:114)
01-16 06:26:45.387 1265 1265 E traceResume: at com.android.launcher3.statemanager.StatefulActivity.onResume(StatefulActivity.java:175)
01-16 06:26:45.387 1265 1265 E traceResume: at com.android.launcher3.Launcher.onResume(Launcher.java:1133)
01-16 06:26:45.387 1265 1265 E traceResume: at com.android.launcher3.BaseQuickstepLauncher.onResume(BaseQuickstepLauncher.java:133)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1488)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.Activity.performResume(Activity.java:8196)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.ActivityThread.performResumeActivity(ActivityThread.java:4814)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:4857)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.servertransaction.ResumeActivityItem.execute(ResumeActivityItem.java:54)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.servertransaction.ActivityTransactionItem.execute(ActivityTransactionItem.java:45)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:176)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2253)
01-16 06:26:45.387 1265 1265 E traceResume: at android.os.Handler.dispatchMessage(Handler.java:106)
01-16 06:26:45.387 1265 1265 E traceResume: at android.os.Looper.loopOnce(Looper.java:201)
01-16 06:26:45.387 1265 1265 E traceResume: at android.os.Looper.loop(Looper.java:288)
01-16 06:26:45.387 1265 1265 E traceResume: at android.app.ActivityThread.main(ActivityThread.java:7870)
01-16 06:26:45.387 1265 1265 E traceResume: at java.lang.reflect.Method.invoke(Native Method)
01-16 06:26:45.387 1265 1265 E traceResume: at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
01-16 06:26:45.387 1265 1265 E traceResume: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
onResume 的时候 执行 IApplicationThread.aidl 的 scheduleTransaction 堆栈
01-16 07:37:38.101 576 1055 E traceReumeService: traceReumeServiceResumeActivityItem{procState=-1,updateProcState=false,isForward=true}
01-16 07:37:38.101 576 1055 E traceReumeService: java.lang.NullPointerException
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.ActivityTaskSupervisor.realStartActivityLocked(ActivityTaskSupervisor.java:878)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.RootWindowContainer.startActivityForAttachedApplicationIfNeeded(RootWindowContainer.java:2013)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.RootWindowContainer.$r8$lambda$auelgeOhCvbItmS_07q5VFEb1ac(Unknown Source:0)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.RootWindowContainer$$ExternalSyntheticLambda2.apply(Unknown Source:8)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.internal.util.function.pooled.PooledLambdaImpl.doInvoke(PooledLambdaImpl.java:318)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.internal.util.function.pooled.PooledLambdaImpl.invoke(PooledLambdaImpl.java:204)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.internal.util.function.pooled.OmniFunction.apply(OmniFunction.java:78)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.ActivityRecord.forAllActivities(ActivityRecord.java:4260)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.WindowContainer.forAllActivities(WindowContainer.java:1449)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.WindowContainer.forAllActivities(WindowContainer.java:1442)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.RootWindowContainer.lambda$attachApplication$15$RootWindowContainer(RootWindowContainer.java:1991)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.RootWindowContainer$$ExternalSyntheticLambda20.accept(Unknown Source:6)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.Task.forAllRootTasks(Task.java:3197)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1825)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1825)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1825)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1825)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1825)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1825)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1818)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.RootWindowContainer.attachApplication(RootWindowContainer.java:1977)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.wm.ActivityTaskManagerService$LocalService.attachApplication(ActivityTaskManagerService.java:6032)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.am.ActivityManagerService.attachApplicationLocked(ActivityManagerService.java:4591)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.am.ActivityManagerService.attachApplication(ActivityManagerService.java:4672)
01-16 07:37:38.101 576 1055 E traceReumeService: at android.app.IActivityManager$Stub.onTransact(IActivityManager.java:2404)
01-16 07:37:38.101 576 1055 E traceReumeService: at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:2518)
01-16 07:37:38.101 576 1055 E traceReumeService: at android.os.Binder.execTransactInternal(Binder.java:1179)
01-16 07:37:38.101 576 1055 E traceReumeService: at android.os.Binder.execTransact(Binder.java:1143)