Are Android's BroadcastReceivers started in a new thread?

Question

If I have an inner class that extends BroadcastReceiver within my Service class, should I care about synchronization, when the BroadcastRecei

Answer 1

Are Android's BroadcastReceivers started in a new thread?

Usually but not always, it all depends on how you register it.

If you register your BroadcastReceiver using:

registerReceiver(BroadcastReceiver receiver, IntentFilter filter)

It will run in the main activity thread(aka UI thread).

If you register your BroadcastReceiver using a valid Handler running on a different thread:

registerReceiver (BroadcastReceiver receiver, IntentFilter filter, String broadcastPermission, Handler scheduler)

It will run in the context of your Handler

For example:

HandlerThread handlerThread = new HandlerThread("ht");
handlerThread.start();
Looper looper = handlerThread.getLooper();
Handler handler = new Handler(looper);
context.registerReceiver(receiver, filter, null, handler); // Will not run on main thread

Details here & here.