接上一篇，我们看看这2个方法做了什么
queue.enqueueOrderedBroadcastLocked(r);
queue.scheduleBroadcastsLocked();
// mOrderedBroadcasts增加一条广播
public void enqueueOrderedBroadcastLocked(BroadcastRecord r) {
mOrderedBroadcasts.add(r);
r.enqueueClockTime = System.currentTimeMillis();
}
第二篇解析了scheduleBroadcastsLocked最终调用processNextBroadcast，step1也解析过，本文接着看step234
final void processNextBroadcast(boolean fromMsg) {
//全程保持AMS锁，其他线程（app进程binder通信）都需要等待此方法处理完毕
synchronized(mService) {
//step1：处理全部无序广播，遍历动态注册的接收者并通知
//step2：获取第一条有序广播
//step3：获取第一个接收者，设置超时
//step4：如果是动态注册的接收者，通知并return
//step5：如果是静态注册的接收者，校验权限
//step6：通知接收者
}
}
step2：获取第一条有序广播
do {
// mOrderedBroadcasts如果没值则return
// 这里再重复说下，sendBroadcast有静态注册的接收者或者sendOrderedBroadcast
// mOrderedBroadcasts会增加一条记录，不会为空
if (mOrderedBroadcasts.size() == 0) {
// No more broadcasts pending, so all done!
mService.scheduleAppGcsLocked();
if (looped) {
// If we had finished the last ordered broadcast, then
// make sure all processes have correct oom and sched
// adjustments.
mService.updateOomAdjLocked();
}
return;
}
r = mOrderedBroadcasts.get(0);
boolean forceReceive = false;
...
} while (r == null);
step3：获取第一个接收者，设置超时
// Get the next receiver...
int recIdx = r.nextReceiver++;
// Keep track of when this receiver started, and make sure there
// is a timeout message pending to kill it if need be.
r.receiverTime = SystemClock.uptimeMillis();
if (recIdx == 0) {
r.dispatchTime = r.receiverTime;
r.dispatchClockTime = System.currentTimeMillis();
}
if (! mPendingBroadcastTimeoutMessage) {
long timeoutTime = r.receiverTime + mTimeoutPeriod;
setBroadcastTimeoutLocked(timeoutTime);
}
...
final Object nextReceiver = r.receivers.get(recIdx);
超时时间就是mTimeoutPeriod
BroadcastQueue(ActivityManagerService service, Handler handler,
String name, long timeoutPeriod, boolean allowDelayBehindServices) {
mService = service;
mHandler = new BroadcastHandler(handler.getLooper());
mQueueName = name;
mTimeoutPeriod = timeoutPeriod;
mDelayBehindServices = allowDelayBehindServices;
}
我们看AMS里
static final int BROADCAST_FG_TIMEOUT = 10*1000;
static final int BROADCAST_BG_TIMEOUT = 60*1000;
mFgBroadcastQueue = new BroadcastQueue(this, mHandler,
"foreground", BROADCAST_FG_TIMEOUT, false);
mBgBroadcastQueue = new BroadcastQueue(this, mHandler,
"background", BROADCAST_BG_TIMEOUT, true);
所以是前台广播10s超时，后台广播（默认是后台广播）60s超时
setBroadcastTimeoutLocked设置超时，关于超时和ANR见后续文章[Broadcast（五）ANR]
step4：如果是动态注册的接收者，通知并return
if (nextReceiver instanceof BroadcastFilter) {
BroadcastFilter filter = (BroadcastFilter)nextReceiver;
// 通知接收者，见[Broadcast（二）registerReceiver时sticky广播]
deliverToRegisteredReceiverLocked(r, filter, r.ordered);
if (r.receiver == null || !r.ordered) {
// The receiver has already finished, so schedule to
// process the next one.
r.state = BroadcastRecord.IDLE;
scheduleBroadcastsLocked();
} else {
if (brOptions != null && brOptions.getTemporaryAppWhitelistDuration() > 0) {
scheduleTempWhitelistLocked(filter.owningUid,
brOptions.getTemporaryAppWhitelistDuration(), r);
}
}
return;
}
step5：如果是静态注册的接收者，校验权限
ResolveInfo info =
(ResolveInfo)nextReceiver;
ComponentName component = new ComponentName(
info.activityInfo.applicationInfo.packageName,
info.activityInfo.name);
boolean skip = false;
int perm = mService.checkComponentPermission(info.activityInfo.permission,
r.callingPid, r.callingUid, info.activityInfo.applicationInfo.uid,
info.activityInfo.exported);
if (perm != PackageManager.PERMISSION_GRANTED) {
skip = true;
} else if (info.activityInfo.permission != null) {
final int opCode = AppOpsManager.permissionToOpCode(info.activityInfo.permission);
if (opCode != AppOpsManager.OP_NONE
&& mService.mAppOpsService.noteOperation(opCode, r.callingUid,
r.callerPackage) != AppOpsManager.MODE_ALLOWED) {
skip = true;
}
}
if (!skip && info.activityInfo.applicationInfo.uid != Process.SYSTEM_UID &&
r.requiredPermissions != null && r.requiredPermissions.length > 0) {
for (int i = 0; i < r.requiredPermissions.length; i++) {
String requiredPermission = r.requiredPermissions[i];
try {
perm = AppGlobals.getPackageManager().
checkPermission(requiredPermission,
info.activityInfo.applicationInfo.packageName,
UserHandle
.getUserId(info.activityInfo.applicationInfo.uid));
} catch (RemoteException e) {
perm = PackageManager.PERMISSION_DENIED;
}
if (perm != PackageManager.PERMISSION_GRANTED) {
skip = true;
break;
}
int appOp = AppOpsManager.permissionToOpCode(requiredPermission);
if (appOp != AppOpsManager.OP_NONE && appOp != r.appOp
&& mService.mAppOpsService.noteOperation(appOp,
info.activityInfo.applicationInfo.uid, info.activityInfo.packageName)
!= AppOpsManager.MODE_ALLOWED) {
skip = true;
break;
}
}
}
if (!skip && r.appOp != AppOpsManager.OP_NONE
&& mService.mAppOpsService.noteOperation(r.appOp,
info.activityInfo.applicationInfo.uid, info.activityInfo.packageName)
!= AppOpsManager.MODE_ALLOWED) {
skip = true;
}
if (!skip) {
skip = !mService.mIntentFirewall.checkBroadcast(r.intent, r.callingUid,
r.callingPid, r.resolvedType, info.activityInfo.applicationInfo.uid);
}
boolean isSingleton = false;
try {
isSingleton = mService.isSingleton(info.activityInfo.processName,
info.activityInfo.applicationInfo,
info.activityInfo.name, info.activityInfo.flags);
} catch (SecurityException e) {
skip = true;
}
if ((info.activityInfo.flags&ActivityInfo.FLAG_SINGLE_USER) != 0) {
if (ActivityManager.checkUidPermission(
android.Manifest.permission.INTERACT_ACROSS_USERS,
info.activityInfo.applicationInfo.uid)
!= PackageManager.PERMISSION_GRANTED) {
skip = true;
}
}
if (r.curApp != null && r.curApp.crashing) {
// If the target process is crashing, just skip it.
skip = true;
}
if (!skip) {
boolean isAvailable = false;
try {
isAvailable = AppGlobals.getPackageManager().isPackageAvailable(
info.activityInfo.packageName,
UserHandle.getUserId(info.activityInfo.applicationInfo.uid));
} catch (Exception e) {
// all such failures mean we skip this receiver
}
if (!isAvailable) {
skip = true;
}
}
if (skip) {
r.receiver = null;
r.curFilter = null;
r.state = BroadcastRecord.IDLE;
scheduleBroadcastsLocked();
return;
}
...
// Broadcast is being executed, its package can't be stopped.
try {
AppGlobals.getPackageManager().setPackageStoppedState(
r.curComponent.getPackageName(), false, UserHandle.getUserId(r.callingUid));
} catch (RemoteException e) {
} catch (IllegalArgumentException e) {
}
step6：通知接收者
// Is this receiver's application already running?
ProcessRecord app = mService.getProcessRecordLocked(targetProcess,
info.activityInfo.applicationInfo.uid, false);
if (app != null && app.thread != null) {
try {
app.addPackage(info.activityInfo.packageName,
info.activityInfo.applicationInfo.versionCode, mService.mProcessStats);
processCurBroadcastLocked(r, app);
return;
} catch (RemoteException e) {
} catch (RuntimeException e) {
r.state = BroadcastRecord.IDLE;
return;
}
...
processCurBroadcastLocked
private final void processCurBroadcastLocked(BroadcastRecord r,
ProcessRecord app) throws RemoteException {
if (app.thread == null) {
throw new RemoteException();
}
r.receiver = app.thread.asBinder();
r.curApp = app;
app.curReceiver = r;
app.forceProcessStateUpTo(ActivityManager.PROCESS_STATE_RECEIVER);
mService.updateLruProcessLocked(app, false, null);
mService.updateOomAdjLocked();
// Tell the application to launch this receiver.
r.intent.setComponent(r.curComponent);
boolean started = false;
try {
mService.ensurePackageDexOpt(r.intent.getComponent().getPackageName());
app.thread.scheduleReceiver(new Intent(r.intent), r.curReceiver,
mService.compatibilityInfoForPackageLocked(r.curReceiver.applicationInfo),
r.resultCode, r.resultData, r.resultExtras, r.ordered, r.userId,
app.repProcState);
started = true;
} finally {
if (!started) {
r.receiver = null;
r.curApp = null;
app.curReceiver = null;
}
}
}
至此只处理了一个receiver，其他receiver呢，我们看下时序图
app receiver处理完毕会通知system，然后接着执行processNextBroadcast，每次执行时r.nextReceiver++
int recIdx = r.nextReceiver++;
...
final Object nextReceiver = r.receivers.get(recIdx);
...
ResolveInfo info = (ResolveInfo)nextReceiver;
...
ProcessRecord app = mService.getProcessRecordLocked(targetProcess,
info.activityInfo.applicationInfo.uid, false);
if (app != null && app.thread != null) {
try {
app.addPackage(info.activityInfo.packageName,
info.activityInfo.applicationInfo.versionCode, mService.mProcessStats);
processCurBroadcastLocked(r, app);
...
到最后receivers.get(recIdx)就取不到值了
