編輯:關於Android編程
一、Android應用程序注冊廣播接收器(registerReceiver)的過程分析
參考Android應用程序注冊廣播接收器(registerReceiver)的過程分析http://blog.csdn.net/luoshengyang/article/details/6737352和《Android系統源代碼情景分析》,作者羅升陽。
0、總圖:
1、MainActivity和CounterService所在應用程序主線程向ActivityManagerService進程發送REGISTER_RECEIVER_TRANSACTION
如圖:第一步
~/Android/frameworks/base/core/java/android/app
----ActivityManagerNative.java
class ActivityManagerProxy implements IActivityManager { ...... public Intent registerReceiver(IApplicationThread caller, IIntentReceiver receiver, IntentFilter filter, String perm) throws RemoteException { Parcel data = Parcel.obtain(); Parcel reply = Parcel.obtain(); data.writeInterfaceToken(IActivityManager.descriptor); data.writeStrongBinder(caller != null ? caller.asBinder() : null); data.writeStrongBinder(receiver != null ? receiver.asBinder() : null); filter.writeToParcel(data, 0); data.writeString(perm); mRemote.transact(REGISTER_RECEIVER_TRANSACTION, data, reply, 0); reply.readException(); Intent intent = null; int haveIntent = reply.readInt(); if (haveIntent != 0) { intent = Intent.CREATOR.createFromParcel(reply); } reply.recycle(); data.recycle(); return intent; } ...... }其中receiver為InnerReceiver對象,如下圖。還要filter,主要關注這兩個參數。
<喎?/kf/ware/vc/" target="_blank" class="keylink">vcD4KPHA+ICAgICAgIMjnzbyjurXatv6yvaOsyqHC1GJpbmRlcl90cmFuc2FjdGlvbrSryuS5/bPMo6zS8s6qyc/D5tLRvq231s72uf3By6GjPC9wPgo8cD48YnI+CjwvcD4KPHA+ICAgICAgIMjnzbyjurXayP2yvTwvcD4KPHA+ICAgICAgIH4vQW5kcm9pZC9mcmFtZXdvcmtzL2Jhc2UvY29yZS9qYXZhL2FuZHJvaWQvYXBwPC9wPgo8cD4gICAgICAgLS0tLUFjdGl2aXR5TWFuYWdlck5hdGl2ZS5qYXZhPC9wPgo8cD48cHJlIGNsYXNzPQ=="brush:java;">public abstract class ActivityManagerNative extends Binder implements IActivityManager
{
......
public boolean onTransact(int code, Parcel data, Parcel reply, int flags)
throws RemoteException {
switch (code) {
case REGISTER_RECEIVER_TRANSACTION:
{
data.enforceInterface(IActivityManager.descriptor);
IBinder b = data.readStrongBinder();
IApplicationThread app =
b != null ? ApplicationThreadNative.asInterface(b) : null;
b = data.readStrongBinder();
IIntentReceiver rec
= b != null ? IIntentReceiver.Stub.asInterface(b) : null;
IntentFilter filter = IntentFilter.CREATOR.createFromParcel(data);
String perm = data.readString();
Intent intent = registerReceiver(app, rec, filter, perm);
reply.writeNoException();
if (intent != null) {
reply.writeInt(1);
intent.writeToParcel(reply, 0);
} else {
reply.writeInt(0);
}
return true;
}
.......
} rec為IIntentReceiver.Stub.Proxy對象,如上圖所示。還要filter,主要關注這兩個參數。
如圖:第四步
~/Android/frameworks/base/services/java/com/android/server/am
----ActivityManagerService.java
public final class ActivityManagerService extends ActivityManagerNative implements Watchdog.Monitor, BatteryStatsImpl.BatteryCallback { ...... public Intent registerReceiver(IApplicationThread caller, IIntentReceiver receiver, IntentFilter filter, String permission) { synchronized(this) { ProcessRecord callerApp = null; if (caller != null) { callerApp = getRecordForAppLocked(caller); if (callerApp == null) { ...... } } ....... ReceiverList rl = (ReceiverList)mRegisteredReceivers.get(receiver.asBinder()); if (rl == null) { rl = new ReceiverList(this, callerApp, Binder.getCallingPid(), Binder.getCallingUid(), receiver); if (rl.app != null) { rl.app.receivers.add(rl); } else { ...... } mRegisteredReceivers.put(receiver.asBinder(), rl); } BroadcastFilter bf = new BroadcastFilter(filter, rl, permission); rl.add(bf); ...... mReceiverResolver.addFilter(bf); // Enqueue broadcasts for all existing stickies that match // this filter. if (allSticky != null) { ...... } return sticky; } } ...... }
(1)根據receiver創建ReceiverList。
(2)根據filter和rl創建BroadcastFilter。
(3)mReceiver.addFilter(bf)。
二、Android應用程序發送廣播(sendBroadcast)的過程分析
0、總圖
1、MainActivity和CounterService所在應用程序主線程向ActivityManagerService進程發送BROADCAST_INTENT_TRANSACTION
如圖:第一步
~/Android/frameworks/base/core/java/android/app
----ActivityManagerNative.java
class ActivityManagerProxy implements IActivityManager { ...... public int broadcastIntent(IApplicationThread caller, Intent intent, String resolvedType, IIntentReceiver resultTo, int resultCode, String resultData, Bundle map, String requiredPermission, boolean serialized, boolean sticky) throws RemoteException { Parcel data = Parcel.obtain(); Parcel reply = Parcel.obtain(); data.writeInterfaceToken(IActivityManager.descriptor); data.writeStrongBinder(caller != null ? caller.asBinder() : null); intent.writeToParcel(data, 0); data.writeString(resolvedType); data.writeStrongBinder(resultTo != null ? resultTo.asBinder() : null); data.writeInt(resultCode); data.writeString(resultData); data.writeBundle(map); data.writeString(requiredPermission); data.writeInt(serialized ? 1 : 0); data.writeInt(sticky ? 1 : 0); mRemote.transact(BROADCAST_INTENT_TRANSACTION, data, reply, 0); reply.readException(); int res = reply.readInt(); reply.recycle(); data.recycle(); return res; } ...... }其中主要關注intent參數。
如圖:第二步,省略binder_transaction傳輸過程,因為上面已經分析過了。
如圖:第三步
~/Android/frameworks/base/core/java/android/app
----ActivityManagerNative.java
public abstract class ActivityManagerNative extends Binder implements IActivityManager { ...... public boolean onTransact(int code, Parcel data, Parcel reply, int flags) throws RemoteException { switch (code) { case BROADCAST_INTENT_TRANSACTION: { data.enforceInterface(IActivityManager.descriptor); IBinder b = data.readStrongBinder(); IApplicationThread app = b != null ? ApplicationThreadNative.asInterface(b) : null; Intent intent = Intent.CREATOR.createFromParcel(data); String resolvedType = data.readString(); b = data.readStrongBinder(); IIntentReceiver resultTo = b != null ? IIntentReceiver.Stub.asInterface(b) : null; int resultCode = data.readInt(); String resultData = data.readString(); Bundle resultExtras = data.readBundle(); String perm = data.readString(); boolean serialized = data.readInt() != 0; boolean sticky = data.readInt() != 0; int res = broadcastIntent(app, intent, resolvedType, resultTo, resultCode, resultData, resultExtras, perm, serialized, sticky); reply.writeNoException(); reply.writeInt(res); return true; } ....... }
如圖:第四步
~/Android/frameworks/base/services/java/com/android/server/am
----ActivityManagerService.java
public final class ActivityManagerService extends ActivityManagerNative implements Watchdog.Monitor, BatteryStatsImpl.BatteryCallback { ...... public final int broadcastIntent(IApplicationThread caller, Intent intent, String resolvedType, IIntentReceiver resultTo, int resultCode, String resultData, Bundle map, String requiredPermission, boolean serialized, boolean sticky) { synchronized(this) { intent = verifyBroadcastLocked(intent); final ProcessRecord callerApp = getRecordForAppLocked(caller); final int callingPid = Binder.getCallingPid(); final int callingUid = Binder.getCallingUid(); final long origId = Binder.clearCallingIdentity(); int res = broadcastIntentLocked(callerApp, callerApp != null ? callerApp.info.packageName : null, intent, resolvedType, resultTo, resultCode, resultData, map, requiredPermission, serialized, sticky, callingPid, callingUid); Binder.restoreCallingIdentity(origId); return res; } } ...... }
(1)根據intent找出相應的廣播接收器:
List(2)根據intent(裡面還包含數據),registeredReceivers創建BroadcastRecord對象,並加入mParallelBroadcasts中:registeredReceivers = null; registeredReceivers = mReceiverResolver.queryIntent(intent, resolvedType, false);
BroadcastRecord r = new BroadcastRecord(intent, callerApp, callerPackage, callingPid, callingUid, requiredPermission, registeredReceivers, resultTo, resultCode, resultData, map, ordered, sticky, false); mParallelBroadcasts.add(r);(3)根據r和從r中得到的BroadcastFilter(即上面注冊時的BroadcastFilter),調用deliverToRegisteredReceiverLocked:
deliverToRegisteredReceiverLocked(r, (BroadcastFilter)target, false);(4)調用filter.receiverList.receiver和new Intent(r.intent)調用performReceiveLocked:
performReceiveLocked(filter.receiverList.app, filter.receiverList.receiver, new Intent(r.intent), r.resultCode, r.resultData, r.resultExtras, r.ordered, r.initialSticky);
app.thread.scheduleRegisteredReceiver(receiver, intent, resultCode, data, extras, ordered, sticky);
其中receiver為IIntentReceiver.Stub.Proxy對象。intent為要傳遞的數據。
2、ActivityManagerService進程向MainActivity和CounterService所在應用程序子線程發送SCHEDULE_REGISTERED_RECEIVER_TRANSACTION
如圖:第一步
~/Android/frameworks/base/core/java/android/app
----ApplicationThreadNative.java,ApplicationThreadProxy類
class ApplicationThreadProxy implements IApplicationThread { ...... public void scheduleRegisteredReceiver(IIntentReceiver receiver, Intent intent, int resultCode, String dataStr, Bundle extras, boolean ordered, boolean sticky) throws RemoteException { Parcel data = Parcel.obtain(); data.writeInterfaceToken(IApplicationThread.descriptor); data.writeStrongBinder(receiver.asBinder()); intent.writeToParcel(data, 0); data.writeInt(resultCode); data.writeString(dataStr); data.writeBundle(extras); data.writeInt(ordered ? 1 : 0); data.writeInt(sticky ? 1 : 0); mRemote.transact(SCHEDULE_REGISTERED_RECEIVER_TRANSACTION, data, null, IBinder.FLAG_ONEWAY); data.recycle(); } ...... }其中receiver為IIntentReceiver.Stub.Proxy對象,intent為要傳遞的數據。
如圖:第三步
~/Android/frameworks/base/core/java/android/app
----ApplicationThreadNative.java
public abstract class ApplicationThreadNative extends Binder implements IApplicationThread { ........ public boolean onTransact(int code, Parcel data, Parcel reply, int flags) throws RemoteException { switch (code) { case SCHEDULE_REGISTERED_RECEIVER_TRANSACTION: { data.enforceInterface(IApplicationThread.descriptor); IIntentReceiver receiver = IIntentReceiver.Stub.asInterface( data.readStrongBinder()); Intent intent = Intent.CREATOR.createFromParcel(data); int resultCode = data.readInt(); String dataStr = data.readString(); Bundle extras = data.readBundle(); boolean ordered = data.readInt() != 0; boolean sticky = data.readInt() != 0; scheduleRegisteredReceiver(receiver, intent, resultCode, dataStr, extras, ordered, sticky); return true; } ....... }其中receiver為InnerReceiver。intent為要傳遞的數據。
如圖:第四步
~/Android/frameworks/base/core/java/android/app
----ActivityThread.java
public final class ActivityThread { ...... private final class ApplicationThread extends ApplicationThreadNative { ...... // This function exists to make sure all receiver dispatching is // correctly ordered, since these are one-way calls and the binder driver // applies transaction ordering per object for such calls. public void scheduleRegisteredReceiver(IIntentReceiver receiver, Intent intent, int resultCode, String dataStr, Bundle extras, boolean ordered, boolean sticky) throws RemoteException { receiver.performReceive(intent, resultCode, dataStr, extras, ordered, sticky); } ...... } ...... }經過一系列折騰,最後在MainActivity和CounterService所在應用程序主線程執行:
receiver.onReceive(mContext, intent);執行onRecevice函數:
public class MainActivity extends Activity implements OnClickListener { ...... private BroadcastReceiver counterActionReceiver = new BroadcastReceiver(){ public void onReceive(Context context, Intent intent) { int counter = intent.getIntExtra(CounterService.COUNTER_VALUE, 0); String text = String.valueOf(counter); counterText.setText(text); Log.i(LOG_TAG, "Receive counter event"); } } ...... }
四大組件的運行狀態: Android中的四大組件中除了BroadcastReceiver以外,其他三種組件都必須在Android Mainfrst中注冊。對於,Bro
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