查看应用的启动流程的源代码应用的启动流程 0

com.android.launcher中执行：
<pre>
W/System.err(  527): java.lang.Exception: kaigo print trace - startActivity
W/System.err(  527): 	at android.app.ActivityManagerProxy.startActivity(ActivityManagerNative.java:1610)
W/System.err(  527): 	at android.app.Instrumentation.execStartActivity(Instrumentation.java:1385)
W/System.err(  527): 	at android.app.Activity.startActivityForResult(Activity.java:3315)
W/System.err(  527): 	at com.android.launcher2.Launcher.startActivityForResult(Launcher.java:1504)
W/System.err(  527): 	at android.app.Activity.startActivity(Activity.java:3422)
W/System.err(  527): 	at com.android.launcher2.Launcher.startActivitySafely(Launcher.java:2025)
W/System.err(  527): 	at com.android.launcher2.AppsCustomizePagedView$3.run(AppsCustomizePagedView.java:539)
W/System.err(  527): 	at com.android.launcher2.PagedView$1.onAnimationRepeat(PagedView.java:1068)
W/System.err(  527): 	at android.animation.ValueAnimator.animationFrame(ValueAnimator.java:1128)
W/System.err(  527): 	at android.animation.ValueAnimator$AnimationHandler.handleMessage(ValueAnimator.java:656)
W/System.err(  527): 	at android.os.Handler.dispatchMessage(Handler.java:99)
W/System.err(  527): 	at android.os.Looper.loop(Looper.java:154)
W/System.err(  527): 	at android.app.ActivityThread.main(ActivityThread.java:4643)
W/System.err(  527): 	at java.lang.reflect.Method.invokeNative(Native Method)
W/System.err(  527): 	at java.lang.reflect.Method.invoke(Method.java:511)
W/System.err(  527): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:811)
W/System.err(  527): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
W/System.err(  527): 	at dalvik.system.NativeStart.main(Native Method)
</pre>

通过 binder 跨进程，进而在 system_server中执行：
<pre>
W/System.err(  305): java.lang.Exception: kaigo print trace - schedulePauseActivity
W/System.err(  305): 	at android.app.ApplicationThreadProxy.schedulePauseActivity(ApplicationThreadNative.java:572)
W/System.err(  305): 	at com.android.server.am.ActivityStack.startPausingLocked(ActivityStack.java:914)
W/System.err(  305): 	at com.android.server.am.ActivityStack.resumeTopActivityLocked(ActivityStack.java:1444)
W/System.err(  305): 	at com.android.server.am.ActivityStack.startActivityLocked(ActivityStack.java:1853)
W/System.err(  305): 	at com.android.server.am.ActivityStack.startActivityUncheckedLocked(ActivityStack.java:2946)
W/System.err(  305): 	at com.android.server.am.ActivityStack.startActivityLocked(ActivityStack.java:2518)
W/System.err(  305): 	at com.android.server.am.ActivityStack.startActivityMayWait(ActivityStack.java:3099)
W/System.err(  305): 	at com.android.server.am.ActivityManagerService.startActivity(ActivityManagerService.java:2535)
W/System.err(  305): 	at android.app.ActivityManagerNative.onTransact(ActivityManagerNative.java:132)
W/System.err(  305): 	at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:1756)
W/System.err(  305): 	at android.os.Binder.execTransact(Binder.java:338)
W/System.err(  305): 	at dalvik.system.NativeStart.run(Native Method)
</pre>

通过 binder，调回 lanucher的 schedulePauseActivity函数：
<pre>
W/System.err(  527): java.lang.Exception: kaigo print trace - schedulePauseActivity
W/System.err(  527): 	at android.app.ActivityThread$ApplicationThread.schedulePauseActivity(ActivityThread.java:530)
W/System.err(  527): 	at android.app.ApplicationThreadNative.onTransact(ApplicationThreadNative.java:78)
W/System.err(  527): 	at android.os.Binder.execTransact(Binder.java:338)
W/System.err(  527): 	at dalvik.system.NativeStart.run(Native Method)
</pre>

launcher进入暂停状态：
<pre>
W/System.err(  527): java.lang.Exception: kaigo print trace - activityPaused
W/System.err(  527): 	at android.app.ActivityManagerProxy.activityPaused(ActivityManagerNative.java:1906)
W/System.err(  527): 	at android.app.ActivityThread.handlePauseActivity(ActivityThread.java:2801)
W/System.err(  527): 	at android.app.ActivityThread.access$800(ActivityThread.java:134)
W/System.err(  527): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1255)
W/System.err(  527): 	at android.os.Handler.dispatchMessage(Handler.java:99)
W/System.err(  527): 	at android.os.Looper.loop(Looper.java:154)
W/System.err(  527): 	at android.app.ActivityThread.main(ActivityThread.java:4643)
W/System.err(  527): 	at java.lang.reflect.Method.invokeNative(Native Method)
W/System.err(  527): 	at java.lang.reflect.Method.invoke(Method.java:511)
W/System.err(  527): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:811)
W/System.err(  527): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
W/System.err(  527): 	at dalvik.system.NativeStart.main(Native Method)
</pre>

通过 socket通知 zygote，为即将启动的 APP fork一个新进程：
<pre>
W/System.err(  305): java.lang.Exception: kaigo print trace
W/System.err(  305): 	at android.os.Process.zygoteSendArgsAndGetResult(Process.java:389)
W/System.err(  305): 	at android.os.Process.startViaZygote(Process.java:525)
W/System.err(  305): 	at android.os.Process.start(Process.java:290)
W/System.err(  305): 	at com.android.server.am.ActivityManagerService.startProcessLocked(ActivityManagerService.java:2225)
W/System.err(  305): 	at com.android.server.am.ActivityManagerService.startProcessLocked(ActivityManagerService.java:2133)
W/System.err(  305): 	at com.android.server.am.ActivityStack.startSpecificActivityLocked(ActivityStack.java:747)
W/System.err(  305): 	at com.android.server.am.ActivityStack.resumeTopActivityLocked(ActivityStack.java:1688)
W/System.err(  305): 	at com.android.server.am.ActivityStack.completePauseLocked(ActivityStack.java:1084)
W/System.err(  305): 	at com.android.server.am.ActivityStack.activityPaused(ActivityStack.java:988)
W/System.err(  305): 	at com.android.server.am.ActivityManagerService.activityPaused(ActivityManagerService.java:4751)
W/System.err(  305): 	at android.app.ActivityManagerNative.onTransact(ActivityManagerNative.java:372)
W/System.err(  305): 	at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:1756)
W/System.err(  305): 	at android.os.Binder.execTransact(Binder.java:338)
W/System.err(  305): 	at dalvik.system.NativeStart.run(Native Method)
</pre>

ZygoteInit.runSelectLoop接收到上面发的 socket，通过 forkAndSpecialize创建进程，完毕通过 ZygoteInit.invokeStaticMain抛出 ZygoteInit.MethodAndArgsCaller异常，清除之前的调用堆栈
<pre>
ZygoteInit.main
└─ZygoteInit.runSelectLoop
    └─ZygoteConnection.runOnce
        └─Zygote.forkAndSpecialize
        └─ZygoteConnection.handleChildProc
            └─ZygoteInit.invokeStaticMain
                └─throw "ZygoteInit.MethodAndArgsCaller" Exception //如此则将之前的调用堆栈清除
└─ZygoteInit.MethodAndArgsCaller.run
</pre>

从此便已进入 App自己的进程，开始执行 App自己的代码，执行 onCreate等函数：
<pre>
W/System.err( 1148): java.lang.Exception: kaigo print trace
W/System.err( 1148): 	at com.example.helloandroid_4_0.MainActivity.onCreate(MainActivity.java:106)
W/System.err( 1148): 	at android.app.Activity.performCreate(Activity.java:4590)
W/System.err( 1148): 	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1050)
W/System.err( 1148): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2042)
W/System.err( 1148): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2105)
W/System.err( 1148): 	at android.app.ActivityThread.access$600(ActivityThread.java:134)
W/System.err( 1148): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1248)
W/System.err( 1148): 	at android.os.Handler.dispatchMessage(Handler.java:99)
W/System.err( 1148): 	at android.os.Looper.loop(Looper.java:154)
W/System.err( 1148): 	at android.app.ActivityThread.main(ActivityThread.java:4643)
W/System.err( 1148): 	at java.lang.reflect.Method.invokeNative(Native Method)
W/System.err( 1148): 	at java.lang.reflect.Method.invoke(Method.java:511)
W/System.err( 1148): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:811)
W/System.err( 1148): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
W/System.err( 1148): 	at dalvik.system.NativeStart.main(Native Method)

</pre>

各 pid对应的进程如下：
<pre>
system    305   116   429368 85188 ffffffff 40019c70 S system_server
app_21    527   116   357424 60444 ffffffff 4001a9a0 S com.android.launcher
app_63    1148  116   297944 52100 ffffffff 4001a9a0 S com.example.helloandroid_4_0
</pre>
----

<pre>
I/ActivityManager(  308): java.lang.RuntimeException: here
I/ActivityManager(  308): 	at com.android.server.am.ActivityStack.startActivityLocked(ActivityStack.java:1754)
I/ActivityManager(  308): 	at com.android.server.am.ActivityStack.startActivityUncheckedLocked(ActivityStack.java:2926)
I/ActivityManager(  308): 	at com.android.server.am.ActivityStack.startActivityLocked(ActivityStack.java:2498)
I/ActivityManager(  308): 	at com.android.server.am.ActivityStack.startActivityMayWait(ActivityStack.java:3079)
I/ActivityManager(  308): 	at com.android.server.am.ActivityManagerService.startActivity(ActivityManagerService.java:2535)
I/ActivityManager(  308): 	at android.app.ActivityManagerNative.onTransact(ActivityManagerNative.java:131)
I/ActivityManager(  308): 	at com.android.server.am.ActivityManagerService.onTransact(ActivityManagerService.java:1756)
I/ActivityManager(  308): 	at android.os.Binder.execTransact(Binder.java:338)
I/ActivityManager(  308): 	at com.android.server.SystemServer.init1(Native Method)
I/ActivityManager(  308): 	at com.android.server.SystemServer.main(SystemServer.java:946)
I/ActivityManager(  308): 	at java.lang.reflect.Method.invokeNative(Native Method)
I/ActivityManager(  308): 	at java.lang.reflect.Method.invoke(Method.java:511)
I/ActivityManager(  308): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:809)
I/ActivityManager(  308): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:576)
I/ActivityManager(  308): 	at dalvik.system.NativeStart.main(Native Method)
</pre>