广播接器BroadcastReceiver

广播Intent和广播接收器BroadcastReceiver，是大家android开发用的特别多的二个控件。

那如何从系统角度看待广播和广播接收器呢？

对于静态注册BroadcastReceiver和动态注册的BroadcastReceiver是如何回调其onReceive方法呢？

此文章以Android13版本为例，试浅分析之。

静态注册BroadcastReceiver回调

对于直接在AndroidManifest.xml静态注册的广播接收器BootReceiver，其回调onReceive过程为：

com.android.server.BootReceiver.onReceive(BootReceiver.java:162)
android.app.ActivityThread.handleReceiver(ActivityThread.java:4376)
android.app.ActivityThread.-$$Nest$mhandleReceiver(Unknown Source:0)
android.app.ActivityThread$H.handleMessage(ActivityThread.java:2191)

其关键回调逻辑为：

ActivityThread.handleReceiver(ActivityThread.java:4376)

//定义BroadcastReceiver
BroadcastReceiver receiver;
......
receiver = packageInfo.getAppFactory()
        .instantiateReceiver(cl, data.info.name, data.intent);
......
try {
    if (localLOGV) Slog.v(
        TAG, "Performing receive of " + data.intent
        + ": app=" + app
        + ", appName=" + app.getPackageName()
        + ", pkg=" + packageInfo.getPackageName()
        + ", comp=" + data.intent.getComponent().toShortString()
        + ", dir=" + packageInfo.getAppDir());

    sCurrentBroadcastIntent.set(data.intent);
    receiver.setPendingResult(data);
    //回调定义BroadcastReceiver的onReceive方法
    receiver.onReceive(context.getReceiverRestrictedContext(),
            data.intent);

动态注册BroadcastReceiver回调

对于我们动态注册BroadcastReceiver的情况:

filter = new IntentFilter();
filter.addAction(intentDynatic);
registerReceiver(mReceiver, filter);

其回调onReceive过程为：

com.example.demo_test.MainActivity$1.onReceive(MainActivity.java:23)
android.app.LoadedApk$ReceiverDispatcher$Args.lambda$getRunnable$0$android-app-LoadedApk$ReceiverDispatcher$Args(LoadedApk.java:1809)
android.app.LoadedApk$ReceiverDispatcher$Args$$ExternalSyntheticLambda0.run(Unknown Source:2)

其关键回调逻辑为：

frameworks/base/core/java/android/app/LoadedApk.java

final class Args extends BroadcastReceiver.PendingResult {
    private Intent mCurIntent;
    private final boolean mOrdered;
    private boolean mDispatched;
    private Throwable mPreviousRunStacktrace; // To investigate b/37809561. STOPSHIP remove.
    .....
    ClassLoader cl = mReceiver.getClass().getClassLoader();
    intent.setExtrasClassLoader(cl);
    intent.prepareToEnterProcess();
    setExtrasClassLoader(cl);
    receiver.setPendingResult(this);
    //需要在这，将intent,receiver,cl信息打印出来
    receiver.onReceive(mContext, intent);

查看设备的广播和广播接收器的整体信息

一般，我们使用以下命令读取设备的intent和BroadcastReceiver信息：
其主要有几种信息：

1.ReceiverList

  * ReceiverList{8f08ba3 2124 com.mediatek.ims/1001/u0 remote:6585ed2}
    app=2124:com.mediatek.ims/1001 pid=2124 uid=1001 user=0
    Filter #0: BroadcastFilter{c094ea0}
      Action: "com.mediatek.ims.ACTION_IMS_SIMULATE"
      Action: "android.intent.action.BOOT_COMPLETED"
      Action: "android.intent.action.SIM_STATE_CHANGED"

2.BroadcastFilter

        android.intent.action.BOOT_COMPLETED:
          BroadcastFilter{80935cb 1000/u-1 ReceiverList{62e389a 1350 system/1000/u-1 local:df35945}}
          BroadcastFilter{337fb81 1000/u-1 ReceiverList{3a64b68 1350 system/1000/u-1 local:273de8b}}
          BroadcastFilter{f263ee2 1000/u-1 ReceiverList{58e70c4 1350 system/1000/u-1 local:4d20fd7}}
          BroadcastFilter{ecb6c7a 1000/u-1 ReceiverList{f7770a5 1350 system/1000/u-1 local:83b8e9c}}
          BroadcastFilter{f11f0f9 10067/u0 ReceiverList{8b14bc0 1566 com.android.systemui/10067/u0 remote:8b3c943}}
          BroadcastFilter{8c9b038 1001/u0 ReceiverList{145949b 1762 com.android.phone/1001/u0 remote:a5890aa}}
          BroadcastFilter{9b1c005 1001/u0 ReceiverList{479ff7c 1762 com.android.phone/1001/u0 remote:6bc466f}}
          BroadcastFilter{662abaa 1001/u0 ReceiverList{ed46e95 1762 com.android.phone/1001/u0 remote:7770e4c}}
          BroadcastFilter{33a7c07 1001/u-1 ReceiverList{5740246 1762 com.android.phone/1001/u-1 remote:9e8ce21}}
          BroadcastFilter{4712dcf 1001/u0 ReceiverList{ec2be2e 1762 com.android.phone/1001/u0 remote:71ee8a9}}
          BroadcastFilter{3c5cb92 1001/u0 ReceiverList{3e1fd1d 1762 com.android.phone/1001/u0 remote:7ef21f4}}
          BroadcastFilter{c094ea0 1001/u0 ReceiverList{8f08ba3 2124 com.mediatek.ims/1001/u0 remote:6585ed2}}
          BroadcastFilter{9131711 1000/u0 ReceiverList{755b38 1350 system/1000/u0 local:f90b9b}}

3.BroadcastRecord

    BroadcastRecord{684f7bd u0 android.intent.action.BOOT_COMPLETED} to user 0
    Intent { act=android.intent.action.BOOT_COMPLETED flg=0x89000010 (has extras) }
      extras: Bundle[{android.intent.extra.user_handle=0}]
    caller=null null pid=1350 uid=1000
    requiredPermissions=[android.permission.RECEIVE_BOOT_COMPLETED]  appOp=-1
    options=Bundle[{android.pendingIntent.backgroundActivityAllowed=true, android:broadcast.temporaryAppAllowlistReasonCode=200, android:broadcast.temporaryAppAllowlistDuration=20000, android:broadcast.temporaryAppAllowlistReason=, android:broadcast.temporaryAppAllowlistType=0}]
    enqueueClockTime=2024-01-16 00:46:29.999 dispatchClockTime=2024-01-16 00:46:31.315
    dispatchTime=-2h30m5s313ms (+1s316ms since enq) finishTime=-2h29m59s267ms (+6s46ms since disp)
    resultTo=null resultCode=0 resultData=null
    resultAbort=false ordered=true sticky=false initialSticky=false
    nextReceiver=59 receiver=null
    Deliver +962ms #0: (manifest)
      priority=2147483647 preferredOrder=0 match=0x108000 specificIndex=-1 isDefault=false
      ActivityInfo:
        name=com.android.traceur.Receiver
        packageName=com.android.traceur
        enabled=true exported=true directBootAware=false
        permission=android.permission.DUMP
        launchMode=0 flags=0x20010000 privateFlags=0x0 theme=0x0
        resizeMode=RESIZE_MODE_RESIZEABLE
        knownActivityEmbeddingCerts={}
    Deliver +2ms #1: BroadcastFilter{80935cb 1000/u-1 ReceiverList{62e389a 1350 system/1000/u-1 local:df35945}}
    Deliver +55ms #2: BroadcastFilter{633e1f 10067/u0 ReceiverList{40c9dbe 1566 com.android.systemui/10067/u0 remote:c8d4c79}}