Android关机流程 一

关机动作从按键触发中断，linux kernel层给android framework层返回按键事件进入 framework层，

再从 framework层到kernel层执行kernel层关机任务。长按键对应的handler代码：

frameworks\policies\base\phone\com\android\internal\policy\impl\phonewindowmanager.java

[cpp] view plaincopyprint?

1. Runnable mPowerLongPress;  
2. private final Runnable mPowerLongPress = new Runnable() {  
3.         public void run() {  
4.             if (!mPowerKeyHandled) {  
5.                 mPowerKeyHandled = true;  
6.                 performHapticFeedbackLw(null, HapticFeedbackConstants.LONG_PRESS, false);  
7.                 sendCloseSystemWindows(SYSTEM_DIALOG_REASON_GLOBAL_ACTIONS);  
8.                 showGlobalActionsDialog();  
9.             }  
10.         }  
11.     };  

调用showglobalactionsdialog() 方法将会显示上面提到的显示 “飞行模式” ，“ 静音” ，“ ” 关机 ，

选项的对话框。

mGlobalActions.showDialog(keyguardShowing, isDeviceProvisioned())该函数是 

mGlobalActions.showDialog()函数定义在frameworks/base/policy/src/com/android/internal/policy/impl/GlobalActions.java文件

其中会调用 createDialog()

private AlertDialog createDialog()中

根据平台不同这里有差异，在createDialog()中

调用mWindowManagerFuncs.shutdown();

此函数在frameworks/base/services/java/com/android/server/pm/ShutdownThread.java实现

此函数中调用shutdownInner(context,confirm); 

[cpp] view plaincopyprint?

1. public static void reboot(final Context context, String reason, boolean confirm) {    
2.        mReboot = true;    
3.        mRebootSafeMode = false;    
4.        mRebootReason = reason;    
5.        shutdownInner(context, confirm);    
6.    }    

shutdownInner函數如下,其調用了beginShutdownSequence(context);

[cpp] view plaincopyprint?

1. static void shutdownInner(final Context context, boolean confirm) {    
2.       ....    
3.  if (confirm) {    
4.             final CloseDialogReceiver closer = new CloseDialogReceiver(context);    
5.             final AlertDialog dialog = new AlertDialog.Builder(context)    
6.                     .setTitle(mRebootSafeMode    
7.                             ? com.android.internal.R.string.reboot_safemode_title    
8.                             : com.android.internal.R.string.power_off)    
9.                     .setMessage(resourceId)    
10.                     .setPositiveButton(com.android.internal.R.string.yes, new DialogInterface.OnClickListener() {    
11.                         public void onClick(DialogInterface dialog, int which) {    
12.                             beginShutdownSequence(context);//調用beginShutdownSequence    
13.                         }    
14.                     })    
15.                     .setNegativeButton(com.android.internal.R.string.no, null)    
16.                     .create();    
17.             closer.dialog = dialog;    
18.             dialog.setOnDismissListener(closer);    
19.             dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);    
20.             dialog.show();    
21.         } else {    
22.             beginShutdownSequence(context);    
23.         }    
24.     }    

beginShutdownSequence如下

[cpp] view plaincopyprint?

1. private static void beginShutdownSequence(Context context) {    
2.            
3.     ......    
4.        sInstance.start();//從這兒就會開始調用到run()方法    
5.    }    

在run()方法中也會做一些reboot之前的清除工作，关掉要关的服务等。

[cpp] view plaincopyprint?

1. public void run() {    
2.        BroadcastReceiver br = new BroadcastReceiver() {    
3.            @Override public void onReceive(Context context, Intent intent) {    
4.                // We don't allow apps to cancel this, so ignore the result.    
5.                actionDone();    
6.            }    
7.        };    
8.     
9.              ......省略    
10.        // Set initial variables and time out time.    
11.        mActionDone = false;    
12.        final long endShutTime = SystemClock.elapsedRealtime() + MAX_SHUTDOWN_WAIT_TIME;    
13.        synchronized (mActionDoneSync) {    
14.            try {    
15.                final IMountService mount = IMountService.Stub.asInterface(    
16.                       ServiceManager.checkService("mount"));    
17.                if (mount != null) {    
18.                    mount.shutdown(observer);    
19.               } else {    
20.                    Log.w(TAG, "MountService unavailable for shutdown");    
21.                }    
22.            } catch (Exception e) {    
23.                Log.e(TAG, "Exception during MountService shutdown", e);    
24.            }    
25.            while (!mActionDone) {    
26.                long delay = endShutTime - SystemClock.elapsedRealtime();    
27.                if (delay <= 0) {    
28.                    Log.w(TAG, "Shutdown wait timed out");    
29.                    break;    
30.                }    
31.                try {    
32.                    mActionDoneSync.wait(delay);    
33.                } catch (InterruptedException e) {    
34.                }    
35.            }    
36.       }    
37.     
38.        rebootOrShutdown(mReboot, mRebootReason);//又繞到rebootOrShutdown函數