Akka 2 and setReceiveTimeout

The Akka documentation states that setReceiveTimeout is

"A timeout mechanism can be used to receive a message when no initial message is received within a certain time."

I was unsure about the "initial message" part and turns out that the underlying actor receives a timeout every time there hasn't been a message within the specified timeframe i.e. not just when no initial message has been received.

Small code sample to show the behaviour of setReceiveTimeout:

	import java.util.Date
	import akka.actor.Actor
	import akka.actor.ActorSystem
	import akka.actor.Props
	import akka.actor.ReceiveTimeout
	import akka.util.duration._
	class MyActor extends Actor {
	context.setReceiveTimeout(5 seconds)
	def receive = {
	case x: String => println(new Date + " / Recieved: " + x)
	case ReceiveTimeout => println(new Date + " / No message received since 5 seconds")
	}
	}
	object Main extends App {
	val sys = ActorSystem("test")
	val a = sys.actorOf(Props[MyActor])
	println(new Date + " / Started")
	Thread.sleep(15000) // expect two timeout messages, one after 5 seconds, next after 10
	// send ten msg's (1 every second) just when we should receive the third timeout
	1 to 10 foreach { x =>
	a ! "Message: " + x
	Thread.sleep(1000)
	}
	// the next timeout message should be received 5 seconds after the loop finishes
	}

view raw SetReceiveTimeoutTest.scala hosted with ❤ by GitHub

Output:

Sun May 27 13:23:57 EST 2012 / Started

Sun May 27 13:24:02 EST 2012 / No message received since 5 seconds

Sun May 27 13:24:07 EST 2012 / No message received since 5 seconds

Sun May 27 13:24:12 EST 2012 / Recieved: Message: 1

Sun May 27 13:24:13 EST 2012 / Recieved: Message: 2

Sun May 27 13:24:14 EST 2012 / Recieved: Message: 3

Sun May 27 13:24:15 EST 2012 / Recieved: Message: 4

Sun May 27 13:24:16 EST 2012 / Recieved: Message: 5

Sun May 27 13:24:17 EST 2012 / Recieved: Message: 6

Sun May 27 13:24:18 EST 2012 / Recieved: Message: 7

Sun May 27 13:24:19 EST 2012 / Recieved: Message: 8

Sun May 27 13:24:20 EST 2012 / Recieved: Message: 9

Sun May 27 13:24:21 EST 2012 / Recieved: Message: 10

Sun May 27 13:24:26 EST 2012 / No message received since 5 seconds

Sun May 27 13:24:31 EST 2012 / No message received since 5 seconds