【Android12】Android Framework系列--AMS启动Activity分析

2023-12-16 11:15

本文主要是介绍【Android12】Android Framework系列--AMS启动Activity分析,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!

AMS启动Activity分析

通过ActivityManagerService(AMS)提供的方法,可以启动指定的Activity。比如Launcher中点击应用图标后,调用AMS的startActivity函数启动应用。
AMS提供的服务通过IActivityManager.aidl文件定义。

// frameworks/base/core/java/android/app/IActivityManager.aidl
package android.app;
// 省略
/*** System private API for talking with the activity manager service.  This* provides calls from the application back to the activity manager.** {@hide}*/
interface IActivityManager {// 省略/** @deprecated Use {@link #startActivityWithFeature} instead */@UnsupportedAppUsage(maxTargetSdk=29, publicAlternatives="Use {@link android.content.Context#startActivity(android.content.Intent)} instead")int startActivity(in IApplicationThread caller, in String callingPackage, in Intent intent,in String resolvedType, in IBinder resultTo, in String resultWho, int requestCode,int flags, in ProfilerInfo profilerInfo, in Bundle options);int startActivityWithFeature(in IApplicationThread caller, in String callingPackage,in String callingFeatureId, in Intent intent, in String resolvedType,in IBinder resultTo, in String resultWho, int requestCode, int flags,in ProfilerInfo profilerInfo, in Bundle options);// 省略
}

代码版本是Android12。分析一下从应用侧(比如Launcher)调用startActivity启动另一个应用的流程。
在这里插入图片描述

startActivity源码分析

应用侧可以通过context的startActivity函数调用AMS。比如下述例子。

Intent intent = new Intent();
// 启动com.linduo.test这个Package中的  MainActivity
intent.setComponent(new ComponentName("com.linduo.test", "com.linduo.test.MainActivity"));
context.startActivity(intent);

context是abstract的类,其实现在ContextImpl中。

// frameworks/base/core/java/android/content/ContextWrapper.java
public class ContextWrapper extends Context {
}// frameworks/base/core/java/android/app/ContextImpl.java
class ContextImpl extends Context {
@Override
public void startActivity(Intent intent) {warnIfCallingFromSystemProcess();startActivity(intent, null);
}@Override
public void startActivity(Intent intent, Bundle options) {warnIfCallingFromSystemProcess();// Calling start activity from outside an activity without FLAG_ACTIVITY_NEW_TASK is// generally not allowed, except if the caller specifies the task id the activity should// be launched in. A bug was existed between N and O-MR1 which allowed this to work. We// maintain this for backwards compatibility.final int targetSdkVersion = getApplicationInfo().targetSdkVersion;if ((intent.getFlags() & Intent.FLAG_ACTIVITY_NEW_TASK) == 0&& (targetSdkVersion < Build.VERSION_CODES.N|| targetSdkVersion >= Build.VERSION_CODES.P)&& (options == null|| ActivityOptions.fromBundle(options).getLaunchTaskId() == -1)) {throw new AndroidRuntimeException("Calling startActivity() from outside of an Activity "+ " context requires the FLAG_ACTIVITY_NEW_TASK flag."+ " Is this really what you want?");}mMainThread.getInstrumentation().execStartActivity(getOuterContext(), mMainThread.getApplicationThread(), null,(Activity) null, intent, -1, options);
}
}

ContextImpl通过mMainThread(ActivityThread类型)得到了Instrumentation对象,调用Instrumentation的execStartActivity函数。execStartActivity函数中,如果开启了Activity监听模式,会通知监听者onStartActivity,然后调用ActivityTaskManagerService的startActivity函数启动Activity。最后检查启动的结果,如果启动失败抛出对应的异常。
onStartActivity的监听,可以使用Instrumentation.addMonitor方式,具体内容可以查看Instrumentation.java

// frameworks/base/core/java/android/app/Instrumentation.java
@UnsupportedAppUsage
public ActivityResult execStartActivity(Context who, IBinder contextThread, IBinder token, Activity target,Intent intent, int requestCode, Bundle options) {IApplicationThread whoThread = (IApplicationThread) contextThread;Uri referrer = target != null ? target.onProvideReferrer() : null;if (referrer != null) {intent.putExtra(Intent.EXTRA_REFERRER, referrer);}if (mActivityMonitors != null) {// 如果开启了监听,会给监听者通过 onStartActivitysynchronized (mSync) {final int N = mActivityMonitors.size();for (int i=0; i<N; i++) {final ActivityMonitor am = mActivityMonitors.get(i);ActivityResult result = null;if (am.ignoreMatchingSpecificIntents()) {result = am.onStartActivity(intent);}if (result != null) {am.mHits++;return result;} else if (am.match(who, null, intent)) {am.mHits++;if (am.isBlocking()) {return requestCode >= 0 ? am.getResult() : null;}break;}}}}try {intent.migrateExtraStreamToClipData(who);intent.prepareToLeaveProcess(who);// 调用ActivityTaskManagerService( AMS中提供的服务)int result = ActivityTaskManager.getService().startActivity(whoThread,who.getOpPackageName(), who.getAttributionTag(), intent,intent.resolveTypeIfNeeded(who.getContentResolver()), token,target != null ? target.mEmbeddedID : null, requestCode, 0, null, options);// 检查启动的结果,如果失败会throw异常。checkStartActivityResult(result, intent);} catch (RemoteException e) {throw new RuntimeException("Failure from system", e);}return null;
}

ActivityTaskManagerService继承了IActivityTaskManager.Stub,属于AMS提供的服务。在其startActivity函数中,会调用startActivityAsUser,判断package与UID是否相符、是否为Isolated模式的应用、并检查用户权限(源码中可以看出系统用户权限非常大,所以为了安全要慎用系统用户权限),最终调用ActivityStarterexecute启动Activity。

// frameworks/base/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@Override
public final int startActivity(IApplicationThread caller, String callingPackage,String callingFeatureId, Intent intent, String resolvedType, IBinder resultTo,String resultWho, int requestCode, int startFlags, ProfilerInfo profilerInfo,Bundle bOptions) {// 调用startActivityAsUserreturn startActivityAsUser(caller, callingPackage, callingFeatureId, intent, resolvedType,resultTo, resultWho, requestCode, startFlags, profilerInfo, bOptions,UserHandle.getCallingUserId());
}@Override
public int startActivityAsUser(IApplicationThread caller, String callingPackage,String callingFeatureId, Intent intent, String resolvedType, IBinder resultTo,String resultWho, int requestCode, int startFlags, ProfilerInfo profilerInfo,Bundle bOptions, int userId) {// 调用startActivityAsUser,validateIncomingUser为truereturn startActivityAsUser(caller, callingPackage, callingFeatureId, intent, resolvedType,resultTo, resultWho, requestCode, startFlags, profilerInfo, bOptions, userId,true /*validateIncomingUser*/);
}private int startActivityAsUser(IApplicationThread caller, String callingPackage,@Nullable String callingFeatureId, Intent intent, String resolvedType,IBinder resultTo, String resultWho, int requestCode, int startFlags,ProfilerInfo profilerInfo, Bundle bOptions, int userId, boolean validateIncomingUser) {// 判断调用的package和UID相符assertPackageMatchesCallingUid(callingPackage);// 禁止来自Isolated模式应用的调用enforceNotIsolatedCaller("startActivityAsUser");// 检测用户权限。这个函数中,可以看出系统用户权限非常大(感兴趣的可以看一下)userId = getActivityStartController().checkTargetUser(userId, validateIncomingUser,Binder.getCallingPid(), Binder.getCallingUid(), "startActivityAsUser");// 通过ActivityStartController,取得ActivityStarter,设置好系列参数后调用execute// TODO: Switch to user app stacks here.return getActivityStartController().obtainStarter(intent, "startActivityAsUser").setCaller(caller).setCallingPackage(callingPackage).setCallingFeatureId(callingFeatureId).setResolvedType(resolvedType).setResultTo(resultTo).setResultWho(resultWho).setRequestCode(requestCode).setStartFlags(startFlags).setProfilerInfo(profilerInfo).setActivityOptions(bOptions).setUserId(userId).execute();}

ActivityStarter的execute函数中,再次进行了一些检查,比如是否存在文件句柄泄露(Intent)、config是否要变更,并调用了executeRequest函数。

// frameworks/base/services/core/java/com/android/server/wm/ActivityStarter.java
int execute() {try {// Refuse possible leaked file descriptorsif (mRequest.intent != null && mRequest.intent.hasFileDescriptors()) {throw new IllegalArgumentException("File descriptors passed in Intent");}final LaunchingState launchingState;synchronized (mService.mGlobalLock) {final ActivityRecord caller = ActivityRecord.forTokenLocked(mRequest.resultTo);final int callingUid = mRequest.realCallingUid == Request.DEFAULT_REAL_CALLING_UID?  Binder.getCallingUid() : mRequest.realCallingUid;launchingState = mSupervisor.getActivityMetricsLogger().notifyActivityLaunching(mRequest.intent, caller, callingUid);}// If the caller hasn't already resolved the activity, we're willing// to do so here. If the caller is already holding the WM lock here,// and we need to check dynamic Uri permissions, then we're forced// to assume those permissions are denied to avoid deadlocking.if (mRequest.activityInfo == null) {mRequest.resolveActivity(mSupervisor);}// Add checkpoint for this shutdown or reboot attempt, so we can record the original// intent action and package name.if (mRequest.intent != null) {String intentAction = mRequest.intent.getAction();String callingPackage = mRequest.callingPackage;if (intentAction != null && callingPackage != null&& (Intent.ACTION_REQUEST_SHUTDOWN.equals(intentAction)|| Intent.ACTION_SHUTDOWN.equals(intentAction)|| Intent.ACTION_REBOOT.equals(intentAction))) {ShutdownCheckPoints.recordCheckPoint(intentAction, callingPackage, null);}}int res;synchronized (mService.mGlobalLock) {final boolean globalConfigWillChange = mRequest.globalConfig != null&& mService.getGlobalConfiguration().diff(mRequest.globalConfig) != 0;// 获取当前处于Top且Focus的RootTaskfinal Task rootTask = mRootWindowContainer.getTopDisplayFocusedRootTask();if (rootTask != null) {// RookTask非空,更新一下ConfigChange的Flag。rootTask.mConfigWillChange = globalConfigWillChange;}ProtoLog.v(WM_DEBUG_CONFIGURATION, "Starting activity when config "+ "will change = %b", globalConfigWillChange);final long origId = Binder.clearCallingIdentity();res = resolveToHeavyWeightSwitcherIfNeeded();if (res != START_SUCCESS) {return res;}// 这个函数中,会创建ActivityRecord,并启动Activityres = executeRequest(mRequest);// 后面的函数,主要是Config的变更。如果有变化会给config变化的通知。// 以及结果的检查。Binder.restoreCallingIdentity(origId);if (globalConfigWillChange) {// If the caller also wants to switch to a new configuration, do so now.// This allows a clean switch, as we are waiting for the current activity// to pause (so we will not destroy it), and have not yet started the// next activity.mService.mAmInternal.enforceCallingPermission(android.Manifest.permission.CHANGE_CONFIGURATION,"updateConfiguration()");if (rootTask != null) {rootTask.mConfigWillChange = false;}ProtoLog.v(WM_DEBUG_CONFIGURATION,"Updating to new configuration after starting activity.");mService.updateConfigurationLocked(mRequest.globalConfig, null, false);}// The original options may have additional info about metrics. The mOptions is not// used here because it may be cleared in setTargetRootTaskIfNeeded.final ActivityOptions originalOptions = mRequest.activityOptions != null? mRequest.activityOptions.getOriginalOptions() : null;// If the new record is the one that started, a new activity has created.final boolean newActivityCreated = mStartActivity == mLastStartActivityRecord;// Notify ActivityMetricsLogger that the activity has launched.// ActivityMetricsLogger will then wait for the windows to be drawn and populate// WaitResult.mSupervisor.getActivityMetricsLogger().notifyActivityLaunched(launchingState, res,newActivityCreated, mLastStartActivityRecord, originalOptions);if (mRequest.waitResult != null) {mRequest.waitResult.result = res;res = waitResultIfNeeded(mRequest.waitResult, mLastStartActivityRecord,launchingState);}return getExternalResult(res);}} finally {onExecutionComplete();}
}

ActivityStarter的executeRequest比较长,下面省略一部分内容。根据其注释内容“Executing activity start request and starts the journey of starting an activity”也可以看出,在这里处理了activity启动的请求。函数中,进行了权限检查,包括判断了是否为Home应用,创建了ActivityRecord记录这次启动为最后一次启动的Activity,然后调用startActivityUnchecked启动应用。

// frameworks/base/services/core/java/com/android/server/wm/ActivityStarter.java
/*** Executing activity start request and starts the journey of starting an activity. Here* begins with performing several preliminary checks. The normally activity launch flow will* go through {@link #startActivityUnchecked} to {@link #startActivityInner}.*/
private int executeRequest(Request request) {// 检查启动 权限boolean abort = !mSupervisor.checkStartAnyActivityPermission(intent, aInfo, resultWho,requestCode, callingPid, callingUid, callingPackage, callingFeatureId,request.ignoreTargetSecurity, inTask != null, callerApp, resultRecord,resultRootTask);abort |= !mService.mIntentFirewall.checkStartActivity(intent, callingUid,callingPid, resolvedType, aInfo.applicationInfo);abort |= !mService.getPermissionPolicyInternal().checkStartActivity(intent, callingUid,callingPackage);boolean restrictedBgActivity = false;if (!abort) {try {Trace.traceBegin(Trace.TRACE_TAG_WINDOW_MANAGER,"shouldAbortBackgroundActivityStart");// 判断是否可以启动Activity.// 这里也会判断是否为Home应用,如果是Home应用的可以启动。如果不是,还要进行其他判断。restrictedBgActivity = shouldAbortBackgroundActivityStart(callingUid,callingPid, callingPackage, realCallingUid, realCallingPid, callerApp,request.originatingPendingIntent, request.allowBackgroundActivityStart,intent);} finally {Trace.traceEnd(Trace.TRACE_TAG_WINDOW_MANAGER);}}// 创建ActivityRecordfinal ActivityRecord r = new ActivityRecord.Builder(mService).setCaller(callerApp).setLaunchedFromPid(callingPid).setLaunchedFromUid(callingUid).setLaunchedFromPackage(callingPackage).setLaunchedFromFeature(callingFeatureId).setIntent(intent).setResolvedType(resolvedType).setActivityInfo(aInfo).setConfiguration(mService.getGlobalConfiguration()).setResultTo(resultRecord).setResultWho(resultWho).setRequestCode(requestCode).setComponentSpecified(request.componentSpecified).setRootVoiceInteraction(voiceSession != null).setActivityOptions(checkedOptions).setSourceRecord(sourceRecord).build();// 记录为最后一次启动的ActivitymLastStartActivityRecord = r;// 调用startActivityUnchecked,启动ActivitymLastStartActivityResult = startActivityUnchecked(r, sourceRecord, voiceSession,request.voiceInteractor, startFlags, true /* doResume */, checkedOptions, inTask,restrictedBgActivity, intentGrants);if (request.outActivity != null) {request.outActivity[0] = mLastStartActivityRecord;}return mLastStartActivityResult;
}

ActivityStarter的startActivityUnchecked函数会调用startActivityInner函数,在这个函数中获取加载Activity的RootTask加载Activity,并调用RootWindowContainer的resumeFocusedTasksTopActivities函数fork出一个进程来运行Activity。


// frameworks/base/services/core/java/com/android/server/wm/ActivityStarter.java/*** Start an activity while most of preliminary checks has been done and caller has been* confirmed that holds necessary permissions to do so.* Here also ensures that the starting activity is removed if the start wasn't successful.*/
private int startActivityUnchecked(final ActivityRecord r, ActivityRecord sourceRecord,IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,int startFlags, boolean doResume, ActivityOptions options, Task inTask,boolean restrictedBgActivity, NeededUriGrants intentGrants) {// 省略try {mService.deferWindowLayout();Trace.traceBegin(Trace.TRACE_TAG_WINDOW_MANAGER, "startActivityInner");// 调用startActivityInnerresult = startActivityInner(r, sourceRecord, voiceSession, voiceInteractor,startFlags, doResume, options, inTask, restrictedBgActivity, intentGrants);} finally {// 省略}postStartActivityProcessing(r, result, startedActivityRootTask);return result;
}/*** Start an activity and determine if the activity should be adding to the top of an existing* task or delivered new intent to an existing activity. Also manipulating the activity task* onto requested or valid root-task/display.** Note: This method should only be called from {@link #startActivityUnchecked}.*/// TODO(b/152429287): Make it easier to exercise code paths through startActivityInner
@VisibleForTesting
int startActivityInner(final ActivityRecord r, ActivityRecord sourceRecord,IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,int startFlags, boolean doResume, ActivityOptions options, Task inTask,boolean restrictedBgActivity, NeededUriGrants intentGrants) {// 省略if (mTargetRootTask == null) {// 获取目标RootTaskmTargetRootTask = getLaunchRootTask(mStartActivity, mLaunchFlags, targetTask, mOptions);}// 调用RootTask,startActivity(细节可以顺着这个函数看)mTargetRootTask.startActivityLocked(mStartActivity,topRootTask != null ? topRootTask.getTopNonFinishingActivity() : null, newTask,mKeepCurTransition, mOptions, sourceRecord);// mDoResume为Tureif (mDoResume) {if (!mTargetRootTask.isTopActivityFocusable()|| (topTaskActivity != null && topTaskActivity.isTaskOverlay()&& mStartActivity != topTaskActivity)) {// 省略} else {// If the target root-task was not previously focusable (previous top running// activity on that root-task was not visible) then any prior calls to move the// root-task to the will not update the focused root-task.  If starting the new// activity now allows the task root-task to be focusable, then ensure that we// now update the focused root-task accordingly.if (mTargetRootTask.isTopActivityFocusable()&& !mRootWindowContainer.isTopDisplayFocusedRootTask(mTargetRootTask)) {mTargetRootTask.moveToFront("startActivityInner");}mRootWindowContainer.resumeFocusedTasksTopActivities(mTargetRootTask, mStartActivity, mOptions, mTransientLaunch);}}mRootWindowContainer.updateUserRootTask(mStartActivity.mUserId, mTargetRootTask);// Update the recent tasks list immediately when the activity startsmSupervisor.mRecentTasks.add(mStartActivity.getTask());mSupervisor.handleNonResizableTaskIfNeeded(mStartActivity.getTask(),mPreferredWindowingMode, mPreferredTaskDisplayArea, mTargetRootTask);return START_SUCCESS;
}

启动的Activity如果是另一个应用,Android会fork出一个进程来加载Activity。那么是在哪里进行的fork?
在ActivityStarter的handleStartResult中,会进行fork进程操作(调用Process.start实现)

// frameworks/base/services/core/java/com/android/server/wm/ActivityStarter.java
/*** Start an activity while most of preliminary checks has been done and caller has been* confirmed that holds necessary permissions to do so.* Here also ensures that the starting activity is removed if the start wasn't successful.*/
private int startActivityUnchecked(final ActivityRecord r, ActivityRecord sourceRecord,IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,int startFlags, boolean doResume, ActivityOptions options, Task inTask,TaskFragment inTaskFragment, boolean restrictedBgActivity,NeededUriGrants intentGrants) {int result = START_CANCELED;final Task startedActivityRootTask;// Create a transition now to record the original intent of actions taken within// startActivityInner. Otherwise, logic in startActivityInner could start a different// transition based on a sub-action.// Only do the create here (and defer requestStart) since startActivityInner might abort.final TransitionController transitionController = r.mTransitionController;Transition newTransition = (!transitionController.isCollecting()&& transitionController.getTransitionPlayer() != null)? transitionController.createTransition(TRANSIT_OPEN) : null;RemoteTransition remoteTransition = r.takeRemoteTransition();if (newTransition != null && remoteTransition != null) {newTransition.setRemoteTransition(remoteTransition);}transitionController.collect(r);try {mService.deferWindowLayout();Trace.traceBegin(Trace.TRACE_TAG_WINDOW_MANAGER, "startActivityInner");result = startActivityInner(r, sourceRecord, voiceSession, voiceInteractor,startFlags, doResume, options, inTask, inTaskFragment, restrictedBgActivity,intentGrants);} finally {Trace.traceEnd(Trace.TRACE_TAG_WINDOW_MANAGER);// 这里会fork出一个进程(调用RootWindowContainer.ensureVisibilityAndConfig),最终调用Process.startstartedActivityRootTask = handleStartResult(r, options, result, newTransition,remoteTransition);mService.continueWindowLayout();}postStartActivityProcessing(r, result, startedActivityRootTask);return result;
}

下面是调用的堆栈(Android13输出的,大概流程一样),感兴趣的可以依照堆栈看源码.

ActivityTaskManager:     at com.android.server.wm.ActivityTaskManagerService.startProcessAsync(ActivityTaskManagerService.java:4683)
ActivityTaskManager:     at com.android.server.wm.ActivityTaskSupervisor.startSpecificActivity(ActivityTaskSupervisor.java:1013)
ActivityTaskManager:     at com.android.server.wm.EnsureActivitiesVisibleHelper.makeVisibleAndRestartIfNeeded(EnsureActivitiesVisibleHelper.java:265)
ActivityTaskManager:     at com.android.server.wm.EnsureActivitiesVisibleHelper.setActivityVisibilityState(EnsureActivitiesVisibleHelper.java:191)
ActivityTaskManager:     at com.android.server.wm.EnsureActivitiesVisibleHelper.process(EnsureActivitiesVisibleHelper.java:139)
ActivityTaskManager:     at com.android.server.wm.TaskFragment.updateActivityVisibilities(TaskFragment.java:985)
ActivityTaskManager:     at com.android.server.wm.Task.lambda$ensureActivitiesVisible$15(Task.java:4866)
ActivityTaskManager:     at com.android.server.wm.Task$$ExternalSyntheticLambda20.accept(Unknown Source:10)
ActivityTaskManager:     at com.android.server.wm.Task.forAllLeafTasks(Task.java:3185)
ActivityTaskManager:     at com.android.server.wm.Task.ensureActivitiesVisible(Task.java:4865)
ActivityTaskManager:     at com.android.server.wm.DisplayContent.lambda$ensureActivitiesVisible$46(DisplayContent.java:6000)
ActivityTaskManager:     at com.android.server.wm.DisplayContent$$ExternalSyntheticLambda17.accept(Unknown Source:10)
ActivityTaskManager:     at com.android.server.wm.Task.forAllRootTasks(Task.java:3197)
ActivityTaskManager:     at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1806)
ActivityTaskManager:     at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1806)
ActivityTaskManager:     at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1806)
ActivityTaskManager:     at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1806)
ActivityTaskManager:     at com.android.server.wm.WindowContainer.forAllRootTasks(WindowContainer.java:1799)
ActivityTaskManager:     at com.android.server.wm.DisplayContent.ensureActivitiesVisible(DisplayContent.java:5999)
ActivityTaskManager:     at com.android.server.wm.RootWindowContainer.ensureActivitiesVisible(RootWindowContainer.java:2075)
ActivityTaskManager:     at com.android.server.wm.RootWindowContainer.ensureVisibilityAndConfig(RootWindowContainer.java:1876)
ActivityTaskManager:     at com.android.server.wm.ActivityStarter.handleStartResult(ActivityStarter.java:1669)
ActivityTaskManager:     at com.android.server.wm.ActivityStarter.startActivityUnchecked(ActivityStarter.java:1598)
ActivityTaskManager:     at com.android.server.wm.ActivityStarter.executeRequest(ActivityStarter.java:1185)
ActivityTaskManager:     at com.android.server.wm.ActivityStarter.execute(ActivityStarter.java:672)
ActivityTaskManager:     at com.android.server.wm.ActivityTaskManagerService.startActivityAsUser(ActivityTaskManagerService.java:1243)
ActivityTaskManager:     at com.android.server.wm.ActivityTaskManagerService.startActivityAsUser(ActivityTaskManagerService.java:1215)
ActivityTaskManager:     at android.app.IActivityTaskManager$Stub.onTransact(IActivityTaskManager.java:969)
ActivityTaskManager:     at com.android.server.wm.ActivityTaskManagerService.onTransact(ActivityTaskManagerService.java:5152)
ActivityTaskManager:     at android.os.Binder.execTransactInternal(Binder.java:1179)
ActivityTaskManager:     at android.os.Binder.execTransact(Binder.java:1143)
ActivityTaskManager: java.lang.Throwable

这篇关于【Android12】Android Framework系列--AMS启动Activity分析的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!



http://www.chinasem.cn/article/500261

相关文章

Nginx分布式部署流程分析

《Nginx分布式部署流程分析》文章介绍Nginx在分布式部署中的反向代理和负载均衡作用,用于分发请求、减轻服务器压力及解决session共享问题,涵盖配置方法、策略及Java项目应用,并提及分布式事... 目录分布式部署NginxJava中的代理代理分为正向代理和反向代理正向代理反向代理Nginx应用场景

Redis中的有序集合zset从使用到原理分析

《Redis中的有序集合zset从使用到原理分析》Redis有序集合(zset)是字符串与分值的有序映射,通过跳跃表和哈希表结合实现高效有序性管理,适用于排行榜、延迟队列等场景,其时间复杂度低,内存占... 目录开篇:排行榜背后的秘密一、zset的基本使用1.1 常用命令1.2 Java客户端示例二、zse

Redis中的AOF原理及分析

《Redis中的AOF原理及分析》Redis的AOF通过记录所有写操作命令实现持久化,支持always/everysec/no三种同步策略,重写机制优化文件体积,与RDB结合可平衡数据安全与恢复效率... 目录开篇:从日记本到AOF一、AOF的基本执行流程1. 命令执行与记录2. AOF重写机制二、AOF的

MyBatis Plus大数据量查询慢原因分析及解决

《MyBatisPlus大数据量查询慢原因分析及解决》大数据量查询慢常因全表扫描、分页不当、索引缺失、内存占用高及ORM开销,优化措施包括分页查询、流式读取、SQL优化、批处理、多数据源、结果集二次... 目录大数据量查询慢的常见原因优化方案高级方案配置调优监控与诊断总结大数据量查询慢的常见原因MyBAT

分析 Java Stream 的 peek使用实践与副作用处理方案

《分析JavaStream的peek使用实践与副作用处理方案》StreamAPI的peek操作是中间操作,用于观察元素但不终止流,其副作用风险包括线程安全、顺序混乱及性能问题,合理使用场景有限... 目录一、peek 操作的本质:有状态的中间操作二、副作用的定义与风险场景1. 并行流下的线程安全问题2. 顺

MyBatis/MyBatis-Plus同事务循环调用存储过程获取主键重复问题分析及解决

《MyBatis/MyBatis-Plus同事务循环调用存储过程获取主键重复问题分析及解决》MyBatis默认开启一级缓存,同一事务中循环调用查询方法时会重复使用缓存数据,导致获取的序列主键值均为1,... 目录问题原因解决办法如果是存储过程总结问题myBATis有如下代码获取序列作为主键IdMappe

Java中最全最基础的IO流概述和简介案例分析

《Java中最全最基础的IO流概述和简介案例分析》JavaIO流用于程序与外部设备的数据交互,分为字节流(InputStream/OutputStream)和字符流(Reader/Writer),处理... 目录IO流简介IO是什么应用场景IO流的分类流的超类类型字节文件流应用简介核心API文件输出流应用文

Android实现图片浏览功能的示例详解(附带源码)

《Android实现图片浏览功能的示例详解(附带源码)》在许多应用中,都需要展示图片并支持用户进行浏览,本文主要为大家介绍了如何通过Android实现图片浏览功能,感兴趣的小伙伴可以跟随小编一起学习一... 目录一、项目背景详细介绍二、项目需求详细介绍三、相关技术详细介绍四、实现思路详细介绍五、完整实现代码

在Android中使用WebView在线查看PDF文件的方法示例

《在Android中使用WebView在线查看PDF文件的方法示例》在Android应用开发中,有时我们需要在客户端展示PDF文件,以便用户可以阅读或交互,:本文主要介绍在Android中使用We... 目录简介:1. WebView组件介绍2. 在androidManifest.XML中添加Interne

Android协程高级用法大全

《Android协程高级用法大全》这篇文章给大家介绍Android协程高级用法大全,本文结合实例代码给大家介绍的非常详细,对大家的学习或工作具有一定的参考借鉴价值,需要的朋友跟随小编一起学习吧... 目录1️⃣ 协程作用域(CoroutineScope)与生命周期绑定Activity/Fragment 中手