当在某个service中想要发送广播，我们就会调用这么的代码：
Intent intent = new Intent(BROADCAST_COUNTER_ACTION);
intent.putExtra(COUNTER_VALUE, counter);
sendBroadcast(intent);
下面我们就对这几行代码进行分析
1、一个广播使用intent来描述的，BROADCAST_COUNTER_ACTION名称就是用来和广播接收者的类型进行匹配的。
public class Intent implements Parcelable, Cloneable {
// ---------------------------------------------------------------------
private String mAction;
private Uri mData;
private String mType;
private String mPackage;
private ComponentName mComponent;
private int mFlags;
private HashSet<String> mCategories;
private Bundle mExtras;
private Rect mSourceBounds;
}
变量mAction和mExtras不为空，其余为空
2、 sendBroadcast(intent)的源码：
public class ContextWrapper extends Context {
Context mBase;
public ContextWrapper(Context base) {
mBase = base;
}
@Override
public void sendBroadcast(Intent intent) {
mBase.sendBroadcast(intent);
}
。。。
}
注释：mBase是一个ContextImpl对象，所以调用的是ContextImpl中的sendBroadcast方法。
3、mBase.sendBroadcast(intent)的源码：
@Override
public void sendBroadcast(Intent intent) {
String resolvedType = intent.resolveTypeIfNeeded(getContentResolver());
try {
ActivityManagerNative.getDefault().broadcastIntent(
mMainThread.getApplicationThread(), intent, resolvedType, null,
Activity.RESULT_OK, null, null, null, false, false);
} catch (RemoteException e) {
}
}
注释：(1)
ActivityManagerNative. getDefault()获得是ActivityManagerProxy对象。
(2) resolvedType为空null
4、ActivityManagerProxy 中的broadcastIntent（）方法的源码：
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;
}
注释：（1）将参数封装成Parcel对象data中。
（2）binder代理对象mRemote向ActivityManagerService发送一个类型为BROADCAST_INTENT_TRANSACTION的进程间通信请求。
5、ActivityManagerService 中的源码：
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;
}
}
6、broadcastIntentLocked（）方法源码：
private final int broadcastIntentLocked(ProcessRecord callerApp,
String callerPackage, Intent intent, String resolvedType,
IIntentReceiver resultTo, int resultCode, String resultData,
Bundle map, String requiredPermission,
boolean ordered, boolean sticky, int callingPid, int callingUid) {
intent = new Intent(intent);
if (DEBUG_BROADCAST_LIGHT) Slog.v(
TAG, (sticky ? "Broadcast sticky: ": "Broadcast: ") + intent
+ " ordered=" + ordered);
if ((resultTo != null) && !ordered) {
Slog.w(TAG, "Broadcast " + intent + " not ordered but result callback requested!");
}
// Handle special intents: if this broadcast is from the package
// manager about a package being removed, we need to remove all of
// its activities from the history stack.
final boolean uidRemoved = intent.ACTION_UID_REMOVED.equals(
intent.getAction());
if (intent.ACTION_PACKAGE_REMOVED.equals(intent.getAction())
|| intent.ACTION_PACKAGE_CHANGED.equals(intent.getAction())
|| Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE.equals(intent.getAction())
|| uidRemoved) {
if (checkComponentPermission(
android.Manifest.permission.BROADCAST_PACKAGE_REMOVED,
callingPid, callingUid, -1)
== PackageManager.PERMISSION_GRANTED) {
if (uidRemoved) {
final Bundle intentExtras = intent.getExtras();
final int uid = intentExtras != null
? intentExtras.getInt(Intent.EXTRA_UID) : -1;
if (uid >= 0) {
BatteryStatsImpl bs = mBatteryStatsService.getActiveStatistics();
synchronized (bs) {
bs.removeUidStatsLocked(uid);
}
}
} else {
// If resources are unvailble just force stop all
// those packages and flush the attribute cache as well.
if (Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE.equals(intent.getAction())) {
String list[] = intent.getStringArrayExtra(Intent.EXTRA_CHANGED_PACKAGE_LIST);
if (list != null && (list.length > 0)) {
for (String pkg : list) {
forceStopPackageLocked(pkg, -1, false, true, true);
}
sendPackageBroadcastLocked(
IApplicationThread.EXTERNAL_STORAGE_UNAVAILABLE, list);
}
} else {
Uri data = intent.getData();
String ssp;
if (data != null && (ssp=data.getSchemeSpecificPart()) != null) {
if (!intent.getBooleanExtra(Intent.EXTRA_DONT_KILL_APP, false)) {
forceStopPackageLocked(ssp,
intent.getIntExtra(Intent.EXTRA_UID, -1), false, true, true);
}
if (intent.ACTION_PACKAGE_REMOVED.equals(intent.getAction())) {
sendPackageBroadcastLocked(IApplicationThread.PACKAGE_REMOVED,
new String[] {ssp});
}
}
}
}
} else {
String msg = "Permission Denial: " + intent.getAction()
+ " broadcast from " + callerPackage + " (pid=" + callingPid
+ ", uid=" + callingUid + ")"
+ " requires "
+ android.Manifest.permission.BROADCAST_PACKAGE_REMOVED;
Slog.w(TAG, msg);
throw new SecurityException(msg);
}
}
/*
* If this is the time zone changed action, queue up a message that will reset the timezone
* of all currently running processes. This message will get queued up before the broadcast
* happens.
*/
if (intent.ACTION_TIMEZONE_CHANGED.equals(intent.getAction())) {
mHandler.sendEmptyMessage(UPDATE_TIME_ZONE);
}
/*
* Prevent non-system code (defined here to be non-persistent
* processes) from sending protected broadcasts.
*/
if (callingUid == Process.SYSTEM_UID || callingUid == Process.PHONE_UID
|| callingUid == Process.SHELL_UID || callingUid == 0) {
// Always okay.
} else if (callerApp == null || !callerApp.persistent) {
try {
if (AppGlobals.getPackageManager().isProtectedBroadcast(
intent.getAction())) {
String msg = "Permission Denial: not allowed to send broadcast "
+ intent.getAction() + " from pid="
+ callingPid + ", uid=" + callingUid;
Slog.w(TAG, msg);
throw new SecurityException(msg);
}
} catch (RemoteException e) {
Slog.w(TAG, "Remote exception", e);
return BROADCAST_SUCCESS;
}
}
// Add to the sticky list if requested.
if (sticky) { //（1）从上面的传值，这里sticky=false
if (checkPermission(android.Manifest.permission.BROADCAST_STICKY,
callingPid, callingUid)
!= PackageManager.PERMISSION_GRANTED) {
String msg = "Permission Denial: broadcastIntent() requesting a sticky broadcast from pid="
+ callingPid + ", uid=" + callingUid
+ " requires " + android.Manifest.permission.BROADCAST_STICKY;
Slog.w(TAG, msg);
throw new SecurityException(msg);
}
if (requiredPermission != null) {
Slog.w(TAG, "Can't broadcast sticky intent " + intent
+ " and enforce permission " + requiredPermission);
return BROADCAST_STICKY_CANT_HAVE_PERMISSION;
}
if (intent.getComponent() != null) {
throw new SecurityException(
"Sticky broadcasts can't target a specific component");
}
ArrayList<Intent> list = mStickyBroadcasts.get(intent.getAction());
if (list == null) {
list = new ArrayList<Intent>();
mStickyBroadcasts.put(intent.getAction(), list);
}
int N = list.size();
int i;
for (i=0; i<N; i++) {
if (intent.filterEquals(list.get(i))) {
// This sticky already exists, replace it.
list.set(i, new Intent(intent));
break;
}
}
if (i >= N) {
list.add(new Intent(intent));
}
}
// Figure out who all will receive this broadcast.
List receivers = null;
List<BroadcastFilter> registeredReceivers = null;
try {
if (intent.getComponent() != null) {
///（2 ）intent.getComponent()获得是广播接收者的名称，发送给特定的广播接收者。从上面的传值来看mComponent为null
// Broadcast is going to one specific receiver class...
ActivityInfo ai = AppGlobals.getPackageManager().
getReceiverInfo(intent.getComponent(), STOCK_PM_FLAGS);
if (ai != null) {
receivers = new ArrayList();
ResolveInfo ri = new ResolveInfo();
ri.activityInfo = ai;
receivers.add(ri);
}
} else {
// Need to resolve the intent to interested receivers...
if ((intent.getFlags()&Intent.FLAG_RECEIVER_REGISTERED_ONLY)
== 0) {
///(3)获得静态注册的广播接收者
receivers =
AppGlobals.getPackageManager().queryIntentReceivers(
intent, resolvedType, STOCK_PM_FLAGS);
}
registeredReceivers = mReceiverResolver.queryIntent(intent, resolvedType, false);
///（4）获得动态注册的广播接收者
}
} catch (RemoteException ex) {
// pm is in same process, this will never happen.
}
final boolean replacePending =
(intent.getFlags()&Intent.FLAG_RECEIVER_REPLACE_PENDING) != 0;
if (DEBUG_BROADCAST) Slog.v(TAG, "Enqueing broadcast: " + intent.getAction()
+ " replacePending=" + replacePending);
int NR = registeredReceivers != null ? registeredReceivers.size() : 0;
if (!ordered && NR > 0) { ///(5)这里为true
// If we are not serializing this broadcast, then send the
// registered receivers separately so they don't wait for the
// components to be launched.
BroadcastRecord r = new BroadcastRecord(intent, callerApp,
callerPackage, callingPid, callingUid, requiredPermission,
registeredReceivers, resultTo, resultCode, resultData, map,
ordered, sticky, false);
if (DEBUG_BROADCAST) Slog.v(
TAG, "Enqueueing parallel broadcast " + r
+ ": prev had " + mParallelBroadcasts.size());
boolean replaced = false;
if (replacePending) {///(6)这里检查是否存在一个这样的无序广播，如果存在替换，如果不存在择添加。
for (int i=mParallelBroadcasts.size()-1; i>=0; i--) {
if (intent.filterEquals(mParallelBroadcasts.get(i).intent)) {
if (DEBUG_BROADCAST) Slog.v(TAG,
"***** DROPPING PARALLEL: " + intent);
mParallelBroadcasts.set(i, r);
replaced = true;
break;
}
}
}
if (!replaced) {
mParallelBroadcasts.add(r);
scheduleBroadcastsLocked(); //然后执行这个方法
}
registeredReceivers = null;
NR = 0;
}
// Merge into one list.
int ir = 0;
if (receivers != null) {
// A special case for PACKAGE_ADDED: do not allow the package
// being added to see this broadcast.This prevents them from
// using this as a back door to get run as soon as they are
// installed.Maybe in the future we want to have a special install
// broadcast or such for apps, but we'd like to deliberately make
// this decision.
String skipPackages[] = null;
if (intent.ACTION_PACKAGE_ADDED.equals(intent.getAction())
|| intent.ACTION_PACKAGE_RESTARTED.equals(intent.getAction())
|| intent.ACTION_PACKAGE_DATA_CLEARED.equals(intent.getAction())) {
Uri data = intent.getData();
if (data != null) {
String pkgName = data.getSchemeSpecificPart();
if (pkgName != null) {
skipPackages = new String[] { pkgName };
}
}
} else if (intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE.equals(intent.getAction())) {
skipPackages = intent.getStringArrayExtra(Intent.EXTRA_CHANGED_PACKAGE_LIST);
}
if (skipPackages != null && (skipPackages.length > 0)) {
for (String skipPackage : skipPackages) {
if (skipPackage != null) {
int NT = receivers.size();
for (int it=0; it<NT; it++) {
ResolveInfo curt = (ResolveInfo)receivers.get(it);
if (curt.activityInfo.packageName.equals(skipPackage)) {
receivers.remove(it);
it--;
NT--;
}
}
}
}
}
int NT = receivers != null ? receivers.size() : 0;
int it = 0;
ResolveInfo curt = null;
BroadcastFilter curr = null;
while (it < NT && ir < NR) {
if (curt == null) {
curt = (ResolveInfo)receivers.get(it);
}
if (curr == null) {
curr = registeredReceivers.get(ir);
}
if (curr.getPriority() >= curt.priority) {
// Insert this broadcast record into the final list.
receivers.add(it, curr);
ir++;
curr = null;
it++;
NT++;
} else {
// Skip to the next ResolveInfo in the final list.
it++;
curt = null;
}
}
}
while (ir < NR) {
if (receivers == null) {
receivers = new ArrayList();
}
receivers.add(registeredReceivers.get(ir));
ir++;
}
if ((receivers != null && receivers.size() > 0)
|| resultTo != null) {
BroadcastRecord r = new BroadcastRecord(intent, callerApp,
callerPackage, callingPid, callingUid, requiredPermission,
receivers, resultTo, resultCode, resultData, map, ordered,
sticky, false);
if (DEBUG_BROADCAST) Slog.v(
TAG, "Enqueueing ordered broadcast " + r
+ ": prev had " + mOrderedBroadcasts.size());
if (DEBUG_BROADCAST) {
int seq = r.intent.getIntExtra("seq", -1);
Slog.i(TAG, "Enqueueing broadcast " + r.intent.getAction() + " seq=" + seq);
}
boolean replaced = false;
if (replacePending) {
for (int i=mOrderedBroadcasts.size()-1; i>0; i--) {
if (intent.filterEquals(mOrderedBroadcasts.get(i).intent)) {
if (DEBUG_BROADCAST) Slog.v(TAG,
"***** DROPPING ORDERED: " + intent);
mOrderedBroadcasts.set(i, r);
replaced = true;
break;
}
}
}
if (!replaced) {
mOrderedBroadcasts.add(r);
scheduleBroadcastsLocked();
}
}
return BROADCAST_SUCCESS;
}
注释：如上面的（1），（2）....
7、scheduleBroadcastsLocked()的源码：
private final void scheduleBroadcastsLocked() {
if (DEBUG_BROADCAST) Slog.v(TAG, "Schedule broadcasts: current="
+ mBroadcastsScheduled);
if (mBroadcastsScheduled) {
return;
}
mHandler.sendEmptyMessage(BROADCAST_INTENT_MSG);
mBroadcastsScheduled = true;
}
注释：mBroadcastsScheduled表示是否已经向所有运行的线程发送了一个类型为BROADCAST_INTENT_MSG的消息。
到这里，广播就发送完了，可以看出广播发送和接受者是异步的
8、mHandler.sendEmptyMessage( BROADCAST_INTENT_MSG)的源码：
final Handler mHandler = new Handler() {
//public Handler() {
//if (localLOGV) Slog.v(TAG, "Handler started!");
//}
public void handleMessage(Message msg) {
switch (msg.what) {
case BROADCAST_INTENT_MSG: {
if (DEBUG_BROADCAST) Slog.v(
TAG, "Received BROADCAST_INTENT_MSG");
processNextBroadcast(true);
} break;
。。。。
}}
解释：mHandler是定义在ActivityManagerService中的变量，用于发送消息。
9、processNextBroadcast(true)的源码：
private final void processNextBroadcast(boolean fromMsg) {
synchronized(this) {
BroadcastRecord r;
if (DEBUG_BROADCAST) Slog.v(TAG, "processNextBroadcast: "
+ mParallelBroadcasts.size() + " broadcasts, "
+ mOrderedBroadcasts.size() + " ordered broadcasts");
updateCpuStats();
if (fromMsg) { //(1)这里为true
mBroadcastsScheduled = false;
}
// First, deliver any non-serialized broadcasts right away.
while (mParallelBroadcasts.size() > 0) { //(2) 这里为true
,因为上面向mParallelBroadcasts添加了数据
r = mParallelBroadcasts.remove(0);
r.dispatchTime = SystemClock.uptimeMillis();
final int N = r.receivers.size();///（3）这里的r.receivers.就是上面创建BroadcastRecord对象时候传入的registeredReceivers
if (DEBUG_BROADCAST_LIGHT) Slog.v(TAG, "Processing parallel broadcast "
+ r);
for (int i=0; i<N; i++) {
Object target = r.receivers.get(i);
if (DEBUG_BROADCAST)Slog.v(TAG,
"Delivering non-ordered to registered "
+ target + ": " + r);
deliverToRegisteredReceiverLocked(r, (BroadcastFilter)target, false);
//执行这行代码
}
addBroadcastToHistoryLocked(r);
if (DEBUG_BROADCAST_LIGHT) Slog.v(TAG, "Done with parallel broadcast "
+ r);
}
// Now take care of the next serialized one...
// If we are waiting for a process to come up to handle the next
// broadcast, then do nothing at this point.Just in case, we
// check that the process we're waiting for still exists.
if (mPendingBroadcast != null) {
if (DEBUG_BROADCAST_LIGHT) {
Slog.v(TAG, "processNextBroadcast: waiting for "
+ mPendingBroadcast.curApp);
}
boolean isDead;
synchronized (mPidsSelfLocked) {
isDead = (mPidsSelfLocked.get(mPendingBroadcast.curApp.pid) == null);
}
if (!isDead) {
// It's still alive, so keep waiting
return;
} else {
Slog.w(TAG, "pending app " + mPendingBroadcast.curApp
+ " died before responding to broadcast");
mPendingBroadcast.state = BroadcastRecord.IDLE;
mPendingBroadcast.nextReceiver = mPendingBroadcastRecvIndex;
mPendingBroadcast = null;
}
}
boolean looped = false;
do {// mOrderedBroadcasts这里是处理有序队列的，因为上面没有传值，就不分析了
if (mOrderedBroadcasts.size() == 0) {
// No more broadcasts pending, so all done!
scheduleAppGcsLocked();
if (looped) {
// If we had finished the last ordered broadcast, then
// make sure all processes have correct oom and sched
// adjustments.
updateOomAdjLocked();
}
return;
}
。。。。。
}
}
10、deliverToRegisteredReceiverLocked(r, (BroadcastFilter)target, false)的源码：
private final void deliverToRegisteredReceiverLocked(BroadcastRecord r,
BroadcastFilter filter, boolean ordered) {
boolean skip = false;
if (filter.requiredPermission != null) {
///(1)检查发送者权限
int perm = checkComponentPermission(filter.requiredPermission,
r.callingPid, r.callingUid, -1);
if (perm != PackageManager.PERMISSION_GRANTED) {
Slog.w(TAG, "Permission Denial: broadcasting "
+ r.intent.toString()
+ " from " + r.callerPackage + " (pid="
+ r.callingPid + ", uid=" + r.callingUid + ")"
+ " requires " + filter.requiredPermission
+ " due to registered receiver " + filter);
skip = true;
}
}
if (r.requiredPermission != null) {
///（2）检查接受者权限
int perm = checkComponentPermission(r.requiredPermission,
filter.receiverList.pid, filter.receiverList.uid, -1);
if (perm != PackageManager.PERMISSION_GRANTED) {
Slog.w(TAG, "Permission Denial: receiving "
+ r.intent.toString()
+ " to " + filter.receiverList.app
+ " (pid=" + filter.receiverList.pid
+ ", uid=" + filter.receiverList.uid + ")"
+ " requires " + r.requiredPermission
+ " due to sender " + r.callerPackage
+ " (uid " + r.callingUid + ")");
skip = true;
}
}
if (!skip) {
// If this is not being sent as an ordered broadcast, then we
// don't want to touch the fields that keep track of the current
// state of ordered broadcasts.
if (ordered) { //这里为false
。。。。
}
try {
if (DEBUG_BROADCAST_LIGHT) {
int seq = r.intent.getIntExtra("seq", -1);
Slog.i(TAG, "Delivering to " + filter
+ " (seq=" + seq + "): " + r);
}
performReceiveLocked(filter.receiverList.app, filter.receiverList.receiver,
new Intent(r.intent), r.resultCode,
r.resultData, r.resultExtras, r.ordered, r.initialSticky);
if (ordered) {
r.state = BroadcastRecord.CALL_DONE_RECEIVE;
}
} catch (RemoteException e) {
Slog.w(TAG, "Failure sending broadcast " + r.intent, e);
if (ordered) {
r.receiver = null;
r.curFilter = null;
filter.receiverList.curBroadcast = null;
if (filter.receiverList.app != null) {
filter.receiverList.app.curReceiver = null;
}
}
}
}
}
11、performReceiveLocked（）源码：
static void performReceiveLocked(ProcessRecord app, IIntentReceiver receiver,
Intent intent, int resultCode, String data, Bundle extras,
boolean ordered, boolean sticky) throws RemoteException {
// Send the intent to the receiver asynchronously using one-way binder calls.
if (app != null && app.thread != null) {
// If we have an app thread, do the call through that so it is
// correctly ordered with other one-way calls.
app.thread.scheduleRegisteredReceiver(receiver, intent, resultCode,
data, extras, ordered, sticky);
} else {
receiver.performReceive(intent, resultCode, data, extras, ordered, sticky);
}
}
App为activity组件，app.thread即为应用运行进程的一个ApplicationThread的代理对象。
12、scheduleRegisteredReceiver源码：
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();
}
13、接下来是ActivityThread中的 的方法
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);
}
注释：参数receiver封装了一个广播接收者
14 、 receiver.performReceive源码：
public void performReceive(Intent intent, int resultCode,
String data, Bundle extras, boolean ordered, boolean sticky) {
LoadedApk.ReceiverDispatcher rd = mDispatcher.get();
if (ActivityThread.DEBUG_BROADCAST) {
int seq = intent.getIntExtra("seq", -1);
Slog.i(ActivityThread.TAG, "Receiving broadcast " + intent.getAction() + " seq=" + seq
+ " to " + (rd != null ? rd.mReceiver : null));
}
if (rd != null) {
rd.performReceive(intent, resultCode, data, extras,
ordered, sticky);
} else {
// The activity manager dispatched a broadcast to a registered
// receiver in this process, but before it could be delivered the
// receiver was unregistered.Acknowledge the broadcast on its
// behalf so that the system's broadcast sequence can continue.
if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
"Finishing broadcast to unregistered receiver");
IActivityManager mgr = ActivityManagerNative.getDefault();
try {
if (extras != null) {
extras.setAllowFds(false);
}
mgr.finishReceiver(this, resultCode, data, extras, false);
} catch (RemoteException e) {
Slog.w(ActivityThread.TAG, "Couldn't finish broadcast to unregistered receiver");
}
}
}
15、rd.performReceive的源码：
public void performReceive(Intent intent, int resultCode,
String data, Bundle extras, boolean ordered, boolean sticky) {
if (ActivityThread.DEBUG_BROADCAST) {
int seq = intent.getIntExtra("seq", -1);
Slog.i(ActivityThread.TAG, "Enqueueing broadcast " + intent.getAction() + " seq=" + seq
+ " to " + mReceiver);
}
Args args = new Args(intent, resultCode, data, extras, ordered, sticky);
if (!mActivityThread.post(args)) {
if (mRegistered && ordered) {
IActivityManager mgr = ActivityManagerNative.getDefault();
if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
"Finishing sync broadcast to " + mReceiver);
args.sendFinished(mgr);
}
}
}
注释：将intent所描述的广播封装成一个args对象，然后把它封装成一个消息，添加到主程序的消息队列中。
16、args的run（）源码：
public void run() {
final BroadcastReceiver receiver = mReceiver;
final boolean ordered = mOrdered;
if (ActivityThread.DEBUG_BROADCAST) {
int seq = mCurIntent.getIntExtra("seq", -1);
Slog.i(ActivityThread.TAG, "Dispatching broadcast " + mCurIntent.getAction()
+ " seq=" + seq + " to " + mReceiver);
Slog.i(ActivityThread.TAG, "mRegistered=" + mRegistered
+ " mOrderedHint=" + ordered);
}
final IActivityManager mgr = ActivityManagerNative.getDefault();
final Intent intent = mCurIntent;
mCurIntent = null;
if (receiver == null || mForgotten) {
if (mRegistered && ordered) {
if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
"Finishing null broadcast to " + mReceiver);
sendFinished(mgr);
}
return;
}
try {
ClassLoader cl =mReceiver.getClass().getClassLoader();
intent.setExtrasClassLoader(cl);
setExtrasClassLoader(cl);
receiver.setPendingResult(this);
receiver.onReceive(mContext, intent);
} catch (Exception e) {
if (mRegistered && ordered) {
if (ActivityThread.DEBUG_BROADCAST) Slog.i(ActivityThread.TAG,
"Finishing failed broadcast to " + mReceiver);
sendFinished(mgr);
}
if (mInstrumentation == null ||
!mInstrumentation.onException(mReceiver, e)) {
throw new RuntimeException(
"Error receiving broadcast " + intent
+ " in " + mReceiver, e);
}
}
if (receiver.getPendingResult() != null) {
finish();
}
}
注释：请看这行代码receiver.onReceive(mContext, intent);，这就是调用了广播接收器中的onReceive方法。我们在自定义中的广播接收器中，经常重写这个方法
