How to wait for Akka actor system to terminate?

Question

I need to start Akka (2.0) actor system, send in some messages, then wait for it to do heavy lifting. After that, I need to do something unrelated to those actors.

I tried to wait for all actors to stop with following code:

val system = new ActorSystem("parallelRunners")
val master = system.actorOf(Props[Master])
master ! Start
system.awaitTermination // <-- hangs here

All actors kill themselves via self ! PoisonPill. What am I doing wrong?

Answer 1

In Akka 2.4.1 for scala 2.11 it appears to be different again.

system.awaitTermination() is deprecated and the docs instruct us to use Await.result(system.whenTerminated, timeout) instead.

As 203 said, system.terminate is still the way to terminate the system.

Here is some example code I used:

val actorSystem = ActorSystem("ActorSystem")
val myActors = actorSystem.actorOf(Props[MyActor].withRouter(RoundRobinPool(10)), "MyActors")
rainbows.foreach(rainbow => myActors ! rainbow)
Await.ready(actorSystem.whenTerminated, Duration(1, TimeUnit.MINUTES))

Then in the MyActor class I have the line context.system.terminate()

Answer 2

As of Akka 2.4, you should use system.awaitTermination() which returns a Future[Terminated] you can wait for.

In order to terminate the system, you should use ActorSystem.terminate (e.g. context.system.terminate() from within an actor when it is finished.

Source: Release Notes