Activity -> startActivity - >
Instrumentation
->execStartActivity
->ActivityManager.getService()
->binder->ActivityManagerService
->IBinder b = ServiceManager.getService(Context.ACTIVITY_SERVICE);
->IActivityManager am = IActivityManager.Stub.asInterface(b)
->ActivityManagerService:
->startActivity
-> startActivityAsUser
->ActivityStarter
->execute()->startActivity->startActivityUnchecked
-> computeLaunchingTaskFlags->computeSourceStack->getReusableIntentActivity
->ActivityStack(作用,结合TaskRecord,ActivityRecord)
->startActivityLocked()
->createWindowContainer()
->showStartingWindow()
