纸上得来终觉浅，绝知此事要躬行。 ------ 宋陆游
基于aosp_cf_x86_64_phone-trunk_staging-eng ， 下面是具体断点位置。
第一部分，桌面launcher进程
com.android.launcher3.touch.ItemClickHandler
- onClick
- onClickAppShortcut
- startAppShortcutOrInfoActivity
com.android.launcher3.Launcher
- startActivitySafely
com.android.launcher3.views.ActivityContext
- startActivitySafely
android.app.Activity
- startActivity(android.content.Intent, android.os.Bundle)
com.android.launcher3.uioverrides.QuickstepLauncher
- startActivityForResult
com.android.launcher3.Launcher
- startActivityForResult
android.app.Activity
- startActivityForResult(android.content.Intent, int, android.os.Bundle)
android.app.Instrumentation
- execStartActivity
第二部分，系统服务进程
com.android.server.wm.ActivityTaskManagerService
- startActivity
- startActivityAsUser
- startActivityAsUser // 初始化了ActivityStarter
com.android.server.wm.ActivityStarter
- execute
- executeRequest // 准备了ActivityRecord
- startActivityUnchecked
- startActivityInner
com.android.server.wm.Task
- startActivityLocked // 准备切换动画，此处WMS,showStartingWindow
com.android.server.wm.StartingSurfaceController
- showStartingWindow
com.android.server.wm.ActivityRecord
- showStartingWindow
com.android.server.wm.RootWindowContainer
- resumeFocusedTasksTopActivities
com.android.server.wm.Task
- resumeTopActivityUncheckedLocked
- resumeTopActivityInnerLocked
com.android.server.wm.TaskFragment
- resumeTopActivity
com.android.server.wm.ActivityTaskManagerService
- startProcessAsync
com.android.server.am.ActivityManagerService.LocalService
- startProcess
com.android.server.am.ActivityManagerService - startProcessLocked
com.android.server.am.ProcessList
- startProcessLocked
com.android.server.am.ProcessList
- startProcessLocked
com.android.server.am.ProcessList
- startProcess
android.os.Process
- start
android.os.ZygoteProcess
- start
- startViaZygote
- zygoteSendArgsAndGetResult
- attemptZygoteSendArgsAndGetResult
android.app.ActivityThread
- main
- attach
com.android.server.am.ActivityManagerService
- attachApplication // 目标进程已启动
- attachApplicationLocked
- finishAttachApplicationInner
// --- ActivityThread
android.app.ActivityThread.ApplicationThread
- bindApplication // 组装一个AppBindData
android.app.ActivityThread.H
- handleMessage
android.app.ActivityThread
- handleBindApplication
android.app.Instrumentation
- callApplicationOnCreate
// --- ActivityThread
com.android.server.wm.ActivityTaskManagerService.LocalService
- attachApplication
com.android.server.wm.RootWindowContainer
- attachApplication
com.android.server.wm.ActivityTaskSupervisor // LaunchActivityItem
- realStartActivityLocked
// While there are activities pausing we skipping starting any new activities until pauses are complete.- if (!mRootWindowContainer.allPausedActivitiesComplete())
com.android.server.wm.ClientLifecycleManager
- scheduleTransactionAndLifecycleItems
- scheduleTransaction
android.app.servertransaction.ClientTransaction
- schedule
第三部分，目标应用进程
android.app.ActivityThread.ApplicationThread
- scheduleTransaction
android.app.ClientTransactionHandler // ActivityThread的父类，此时，ActivityThread已经启动了
- scheduleTransaction
android.app.ActivityThread.H
- handleMessage // EXECUTE_TRANSACTION
android.app.servertransaction.TransactionExecutor
- execute
- executeLifecycleState
- executeLifecycleItem
android.app.servertransaction.ActivityTransactionItem
- execute(android.app.ClientTransactionHandler, android.app.servertransaction.PendingTransactionActions)
android.app.servertransaction.LaunchActivityItem //ActivityClientRecord
- execute
android.app.ActivityThread
- handleLaunchActivity // 这里已经触发了ON_CREATE
android.app.ActivityThread
- performLaunchActivity
android.app.Instrumentation
- newActivity(java.lang.ClassLoader, java.lang.String, android.content.Intent)
android.app.Activity
- attach // 此时出现PhoneWindow 窗口
android.app.Instrumentation
- callActivityOnCreate(android.app.Activity, android.os.Bundle)
android.app.Activity
- performCreate(android.os.Bundle)
- onCreate(android.os.Bundle)
时序图
