activity启动过程

TransactionExecutor#execute（）

Instrumentation#callActivityOnCreate()

executeCallbacks(transaction);

LaunchActivityItem#excute()

mClient.scheduleTransaction(this);

ActivityManagerService#attachApplication()

Launcher#startActivitySafely()

AMS---->ActivityThread

ActivityStackSupervisor#startSpecificActivityLocked()

Activity#performCreate();

普通Activity

ActivityManagerService#getLifecycleManager().scheduleTransaction();

Activity启动源码分析（Android28_9.0）普通Activity启动过程：1.应用进程IPC调用AMS2.AMS使用IPC调用ActivityThread3.ActivityThread启动Activity

Launcher启动根Activity

startActivityForResult

1.这里IApplicationThread是一个IPC接口，它调用scheduleTransaction(this)是一次IPC调用。2.IApplicationThread的实现类是ApplicationThread，它继承了IApplicationThread.Stub.3.ApplicationThread是ActivityThread的内部类

ActivityStackSuperVisor#attachApplicationLocked()

onCreate()

ActivityThread#main()

mStackSupervisor.attachApplicationLocked(app)

mService.getLifecycleManager().scheduleTransaction(clientTransaction);

ClientTransactionHandler#scheduleTransaction(transaction)

Activity启动源码分析（Android28_9.0）根Activity启动过程：1.Launcher进程启动AMS2.AMS启动应用进程3.AMS使用IPC调用ActivityThread4.ActivityThread启动Activity

transaction.schedule();

ClientTransaction#schedule();

根Activity

用户点击桌面图标触发Launcher#startActivitySafely()

Activity#startActivity

Instrumentation#execStartActivity()

IApplicationThread#scheduleTransaction(this)

IActivityManager#startActivity()

Activity#startActivity()

ClientLifecycleManager#scheduleTransaction();

ClientTransactionItem#excute()

这里是AMS请求启动应用进程，之后系统ZYGOTE会孵化出应用进程，应用进程启动后，会先进入Activity#main()方法中

ActivityThread#handleLaunchActivity()

ActivityStackSupervisor#resumeFocusedStackTopActivityLocked()

H#handleMessage:case H.EXECUTE_TRANSACTION:

ActivityStartController#obtainStarter()

Activity---->AMS

ApplicationThread#scheduleTransaction(transaction)

ActivityThread.this.scheduleTransaction(transaction);

ActivityThread启动Activity

ActivityStack#resumeTopActivityUncheckedLocked()

startActivity(...)

ClientTransactionHandler#handleLaunchActivity()

resumeTopActivityInnerLocked()

ActivityManageService#startActivity()

BaseDraggingActivity#startActivitySafely()

1.这里IActivityManager是通过IActivityManagerSingleton.get()得到的，其内部是final IActivityManager am = IActivityManager.Stub.asInterface(b);初始化的，可以得知，IActivityManager是IPC接口，它执行startActivity是一次IPC调用。2.这个IPC的另一端是ActivityManageService，它实现了IActivityManager.Stub

startActivityMayWait(...)

ActivityStarter#excute()

ActivityThread#scheduleTransaction(transaction)

     mTransactionExecutor.execute(transaction);