注册过程
@Override
public Intent registerReceiver(BroadcastReceiver receiver, IntentFilter filter) {
return registerReceiver(receiver, filter, null, null);
}
@Override
public Intent registerReceiver(BroadcastReceiver receiver, IntentFilter filter,
String broadcastPermission, Handler scheduler) {
return registerReceiverInternal(receiver, getUserId(),
filter, broadcastPermission, scheduler, getOuterContext(), 0);
}
private Intent registerReceiverInternal(BroadcastReceiver receiver, int userId,
IntentFilter filter, String broadcastPermission,
Handler scheduler, Context context, int flags) {
//IIntentReceiver 是个binder接口，用于进程通信
IIntentReceiver rd = null;
if (receiver != null) {
if (mPackageInfo != null && context != null) {
if (scheduler == null) {
scheduler = mMainThread.getHandler();
}
//获取rd
rd = mPackageInfo.getReceiverDispatcher(
receiver, context, scheduler,
mMainThread.getInstrumentation(), true);
} else {
if (scheduler == null) {
scheduler = mMainThread.getHandler();
}
//创建rd
rd = new LoadedApk.ReceiverDispatcher(
receiver, context, scheduler, null, true).getIIntentReceiver();
}
}
try {
//调用的是ActivityManagerService的registerReceiver
final Intent intent = ActivityManager.getService().registerReceiver(
mMainThread.getApplicationThread(), mBasePackageName, rd, filter,
broadcastPermission, userId, flags);
if (intent != null) {
intent.setExtrasClassLoader(getClassLoader());
intent.prepareToEnterProcess();
}
return intent;
} catch (RemoteException e) {
throw e.rethrowFromSystemServer();
}
}
rd是个binder驱动，它的具体实现类是LoadApk的ReceiverDispatcher类中的InnerReceiver
static final class ReceiverDispatcher {
final static class InnerReceiver extends IIntentReceiver.Stub {
final WeakReference<LoadedApk.ReceiverDispatcher> mDispatcher;
final LoadedApk.ReceiverDispatcher mStrongRef;
InnerReceiver(LoadedApk.ReceiverDispatcher rd, boolean strong) {
mDispatcher = new WeakReference<LoadedApk.ReceiverDispatcher>(rd);
mStrongRef = strong ? rd : null;
}
}
}
回到AMS的registerReceiver
public Intent registerReceiver(IApplicationThread caller, String callerPackage,
IIntentReceiver receiver, IntentFilter filter, String permission, int userId,
int flags) {
synchronized(this) {
//得到所有粘性的广播
Iterator<String> actions = filter.actionsIterator();
// Collect stickies of users
int[] userIds = { UserHandle.USER_ALL, UserHandle.getUserId(callingUid) };
while (actions.hasNext()) {
String action = actions.next();
for (int id : userIds) {
ArrayMap<String, ArrayList<Intent>> stickies = mStickyBroadcasts.get(id);
if (stickies != null) {
ArrayList<Intent> intents = stickies.get(action);
if (intents != null) {
if (stickyIntents == null) {
stickyIntents = new ArrayList<Intent>();
}
stickyIntents.addAll(intents);
}
}
}
}
}
ArrayList<Intent> allSticky = null;
if (stickyIntents != null) {
final ContentResolver resolver = mContext.getContentResolver();
//遍历所有粘性广播的集合
for (int i = 0, N = stickyIntents.size(); i < N; i++) {
Intent intent = stickyIntents.get(i);
// Don't provided intents that aren't available to instant apps.
if (instantApp &&
(intent.getFlags() & Intent.FLAG_RECEIVER_VISIBLE_TO_INSTANT_APPS) == 0) {
continue;
}
if (filter.match(resolver, intent, true, TAG) >= 0) {
if (allSticky == null) {
allSticky = new ArrayList<Intent>();
}
//所有粘性的广播添加到allSticky集合中
allSticky.add(intent);
}
}
}
synchronized (this) {
ReceiverList rl = mRegisteredReceivers.get(receiver.asBinder());
if (rl == null) {
//ReceiverList 若为空则new一个新的ReceiverList
rl = new ReceiverList(this, callerApp, callingPid, callingUid,
userId, receiver);
rl.app.receivers.add(rl);
}
//BroadcastFilter 用来描述注册的广播接受者
BroadcastFilter bf = new BroadcastFilter(filter, rl, callerPackage,
permission, callingUid, userId, instantApp, visibleToInstantApps);
if (rl.containsFilter(filter)) {
} else {
//BroadcastFilter 添加到ReceiverList集合中
rl.add(bf);
if (!bf.debugCheck()) {
Slog.w(TAG, "==> For Dynamic broadcast");
}
//再添加到mReceiverResolver
mReceiverResolver.addFilter(bf);
}
return sticky;
}
}
广播的发送sendBroadcast
@Override
public void sendBroadcast(Intent intent) {
warnIfCallingFromSystemProcess();
String resolvedType = intent.resolveTypeIfNeeded(getContentResolver());
try {
intent.prepareToLeaveProcess(this);
ActivityManager.getService().broadcastIntent(
mMainThread.getApplicationThread(), intent, resolvedType, null,
Activity.RESULT_OK, null, null, null, AppOpsManager.OP_NONE, null, false, false,
getUserId());
} catch (RemoteException e) {
throw e.rethrowFromSystemServer();
}
}
public final int broadcastIntent(IApplicationThread caller,
Intent intent, String resolvedType, IIntentReceiver resultTo,
int resultCode, String resultData, Bundle resultExtras,
String[] requiredPermissions, int appOp, Bundle bOptions,
boolean serialized, boolean sticky, int userId) {
enforceNotIsolatedCaller("broadcastIntent");
synchronized(this) {
//验证广播是否合法
intent = verifyBroadcastLocked(intent);
int res = broadcastIntentLocked(callerApp,
callerApp != null ? callerApp.info.packageName : null,
intent, resolvedType, resultTo, resultCode, resultData, resultExtras,
requiredPermissions, appOp, bOptions, serialized, sticky,
callingPid, callingUid, userId);
Binder.restoreCallingIdentity(origId);
return res;
}
}
final Intent verifyBroadcastLocked(Intent intent) {
if (intent != null && intent.hasFileDescriptors() == true) {
//如果intent不为null,且有文件描述符则抛出异常
throw new IllegalArgumentException("File descriptors passed in Intent");
}
//获取flgs
int flags = intent.getFlags();
if (!mProcessesReady) {
if ((flags&Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT) != 0) {
//FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT表示启动检查时只接受动态注册的广播接受者
} else if ((flags&Intent.FLAG_RECEIVER_REGISTERED_ONLY) == 0) {
Slog.e(TAG, "Attempt to launch receivers of broadcast intent " + intent
+ " before boot completion");
throw new IllegalStateException("Cannot broadcast before boot completed");
}
}
if ((flags&Intent.FLAG_RECEIVER_BOOT_UPGRADE) != 0) {
throw new IllegalArgumentException(
"Can't use FLAG_RECEIVER_BOOT_UPGRADE here");
}
return intent;
}
final int broadcastIntentLocked(ProcessRecord callerApp,
String callerPackage, Intent intent, String resolvedType,
IIntentReceiver resultTo, int resultCode, String resultData,
Bundle resultExtras, String[] requiredPermissions, int appOp, Bundle bOptions,
boolean ordered, boolean sticky, int callingPid, int callingUid, int userId) {
//将动态注册和动态注册的广播按照优先级高低存储再不同的列表中,receivers 包含所有广播，有序广播和无序广播
if ((receivers != null && receivers.size() > 0)
|| resultTo != null) {
BroadcastQueue queue = broadcastQueueForIntent(intent);
BroadcastRecord r = new BroadcastRecord(queue, intent, callerApp,
callerPackage, callingPid, callingUid, callerInstantApp, resolvedType,
requiredPermissions, appOp, brOptions, receivers, resultTo, resultCode,
resultData, resultExtras, ordered, sticky, false, userId);
final BroadcastRecord oldRecord =
replacePending ? queue.replaceOrderedBroadcastLocked(r) : null;
if (oldRecord != null) {
} else {
queue.enqueueOrderedBroadcastLocked(r);
queue.scheduleBroadcastsLocked();
}
} else {
if (intent.getComponent() == null && intent.getPackage() == null
&& (intent.getFlags()&Intent.FLAG_RECEIVER_REGISTERED_ONLY) == 0) {
// This was an implicit broadcast... let's record it for posterity.
addBroadcastStatLocked(intent.getAction(), callerPackage, 0, 0, 0);
}
}
return ActivityManager.BROADCAST_SUCCESS;
}
public void scheduleBroadcastsLocked() {
mHandler.sendMessage(mHandler.obtainMessage(BROADCAST_INTENT_MSG, this));
mBroadcastsScheduled = true;
}
private final class BroadcastHandler extends Handler {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case BROADCAST_INTENT_MSG: {
processNextBroadcast(true);
} break;
}
}
}
final void processNextBroadcast(boolean fromMsg) {
synchronized (mService) {
processNextBroadcastLocked(fromMsg, false);
}
}
final void processNextBroadcastLocked(boolean fromMsg, boolean skipOomAdj) {
BroadcastRecord r;
//fromMsg=true skipOomAdj=false
if (fromMsg) {
//mBroadcastsScheduled 设置为false,表示之前发来的BROADCAST_INTENT_MSG消息类型已经处理了
mBroadcastsScheduled = false;
}
//mParallelBroadcasts用来存储无序广播
while (mParallelBroadcasts.size() > 0) {
//获取BroadcastRecord类型的r对象
r = mParallelBroadcasts.remove(0);
for (int i=0; i<N; i++) {
Object target = r.receivers.get(i);
//发送给对应的广播接受者
deliverToRegisteredReceiverLocked(r, (BroadcastFilter)target, false, i);//4
}
}
}
private void deliverToRegisteredReceiverLocked(BroadcastRecord r,
BroadcastFilter filter, boolean ordered, int index) {
boolean skip = false;
//检查权限
//省略代码
try {
if (filter.receiverList.app != null && filter.receiverList.app.inFullBackup) {
} else {
//通过了权限的检查
performReceiveLocked(filter.receiverList.app, filter.receiverList.receiver,
new Intent(r.intent), r.resultCode, r.resultData,
r.resultExtras, r.ordered, r.initialSticky, r.userId);
}
if (ordered) {
r.state = BroadcastRecord.CALL_DONE_RECEIVE;
}
} catch (RemoteException e) {
}
}
void performReceiveLocked(ProcessRecord app, IIntentReceiver receiver,
Intent intent, int resultCode, String data, Bundle extras,
boolean ordered, boolean sticky, int sendingUser) throws RemoteException {
if (app != null) {
//广播接受者所在的进程正在运行
if (app.thread != null) {
try {
app.thread.scheduleRegisteredReceiver(receiver, intent, resultCode,
data, extras, ordered, sticky, sendingUser, app.repProcState);
} catch (RemoteException ex) {
}
} else {
}
} else {
receiver.performReceive(intent, resultCode, data, extras, ordered,
sticky, sendingUser);
}
}
public void scheduleRegisteredReceiver(IIntentReceiver receiver, Intent intent,
int resultCode, String dataStr, Bundle extras, boolean ordered,
boolean sticky, int sendingUser, int processState) throws RemoteException {
updateProcessState(processState, false);
//IIntentReceiver的perfromReceive
receiver.performReceive(intent, resultCode, dataStr, extras, ordered,
sticky, sendingUser);
}
上面我们分析我们知道IIntentReceiver的实现类是LoadApk类中的ReceiverDispatcher的InnerReceiver对象
static final class ReceiverDispatcher {
final static class InnerReceiver extends IIntentReceiver.Stub {
final WeakReference<LoadedApk.ReceiverDispatcher> mDispatcher;
final LoadedApk.ReceiverDispatcher mStrongRef;
@Override
public void performReceive(Intent intent, int resultCode, String data,
Bundle extras, boolean ordered, boolean sticky, int sendingUser) {
final LoadedApk.ReceiverDispatcher rd;
if (rd != null) {
rd.performReceive(intent, resultCode, data, extras,
ordered, sticky, sendingUser);
}
}
}
public void performReceive(Intent intent, int resultCode, String data,
Bundle extras, boolean ordered, boolean sticky, int sendingUser) {
//intent对象封装成Args对象
final Args args = new Args(intent, resultCode, data, extras, ordered,
sticky, sendingUser);
//mActivityThread是个Handler，调用的是args的run方法
if (intent == null || !mActivityThread.post(args.getRunnable())) {
if (mRegistered && ordered) {
IActivityManager mgr = ActivityManager.getService();
args.sendFinished(mgr);
}
}
}
public final Runnable getRunnable() {
return () -> {
Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "broadcastReceiveReg");
try {
ClassLoader cl = mReceiver.getClass().getClassLoader();
intent.setExtrasClassLoader(cl);
intent.prepareToEnterProcess();
setExtrasClassLoader(cl);
receiver.setPendingResult(this);
//最终走到receiver的onReceive
receiver.onReceive(mContext, intent);
}
if (receiver.getPendingResult() != null) {
finish();
}
Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER);
};
}
广播接受者.png
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