PowerManagerService分析之Notifier分析

这个类在PowerManagerService中是非常重要的，当PowerManagerService的状态改变时，都是靠这个类通知。比如常用的灭屏和亮屏广播，也是在这个类中发送的。

一、Notifier初始化

首先我们来看它在PowerManagerService构造函数中的初始化：

  mNotifier = new Notifier(Looper.getMainLooper(), mContext, mBatteryStats,
                    mAppOps, createSuspendBlockerLocked("PowerManagerService.Broadcasts"),
                    mPolicy);

PowerManagerService把自己的main looper传进去了，说明在Notifier的消息处理是在PowerManagerService的主线程中，还有一点和之前的WakeLocks，和Display锁一样，这里也为Notifier创建了一个Broadcasts锁。

Notifier类

public Notifier(Looper looper, Context context, IBatteryStats batteryStats,
            IAppOpsService appOps, SuspendBlocker suspendBlocker,
            WindowManagerPolicy policy) {
   
        mContext = context;
        mBatteryStats = batteryStats;
        mAppOps = appOps;
        mSuspendBlocker = suspendBlocker;
        mPolicy = policy;
        mActivityManagerInternal = LocalServices.getService(ActivityManagerInternal.class);
        mInputManagerInternal = LocalServices.getService(InputManagerInternal.class);
        mInputMethodManagerInternal = LocalServices.getService(InputMethodManagerInternal.class);

        mHandler = new NotifierHandler(looper);
        mScreenOnIntent = new Intent(Intent.ACTION_SCREEN_ON);
        ...
        // Initialize interactive state for battery stats.
        try {
   
            mBatteryStats.noteInteractive(true);
        } catch (RemoteException ex) {
    }
    }

//
private final class NotifierHandler extends Handler {
   
        public NotifierHandler(Looper looper) {
   
            super(looper, null, true /*async*/);
        }

        @Override
        public void handleMessage(Message msg) {
   
            switch (msg.what) {
   
                case MSG_USER_ACTIVITY:
                    sendUserActivity();
                    break;

                case MSG_BROADCAST:
                    sendNextBroadcast();
                    break;

                case MSG_WIRELESS_CHARGING_STARTED:
                    playWirelessChargingStartedSound();
                    break;
                case MSG_SCREEN_BRIGHTNESS_BOOST_CHANGED:
                    sendBrightnessBoostChangedBroadcast();
                    break;
            }
        }
    }

二、唤醒

在PowerManagerService的wakeUpNoUpdateLocked函数会调用如下函数：

mNotifier.onWakeUp(reason, reasonUid, opPackageName, opUid);

再看下Notifier处理：

public void onWakeUp(String reason, int reasonUid, String opPackageName, int opUid) {
   
        try {
   
            mBatteryStats.noteWakeUp(reason, reasonUid