Akka/Scala example source code file (ScatterGatherFirstCompletedSpec.scala)

This example Akka source code file (ScatterGatherFirstCompletedSpec.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, akka, atomicinteger, broadcast, concurrent, int, list, none, routing, scattergatherfirstcompletedspec, some, stop, test, testing, testlatch, time

The ScatterGatherFirstCompletedSpec.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package akka.routing

import java.util.concurrent.atomic.AtomicInteger
import scala.concurrent.Await
import scala.concurrent.duration._
import akka.actor.{ Props, Actor }
import akka.pattern.ask
import akka.testkit.{ TestLatch, ImplicitSender, DefaultTimeout, AkkaSpec }
import akka.actor.ActorSystem

object ScatterGatherFirstCompletedSpec {
  class TestActor extends Actor {
    def receive = { case _ ⇒ }
  }

  final case class Stop(id: Option[Int] = None)

  def newActor(id: Int, shudownLatch: Option[TestLatch] = None)(implicit system: ActorSystem) =
    system.actorOf(Props(new Actor {
      def receive = {
        case Stop(None)                     ⇒ context.stop(self)
        case Stop(Some(_id)) if (_id == id) ⇒ context.stop(self)
        case _id: Int if (_id == id)        ⇒
        case x ⇒ {
          Thread sleep 100 * id
          sender() ! id
        }
      }

      override def postStop = {
        shudownLatch foreach (_.countDown())
      }
    }), "Actor:" + id)
}

@org.junit.runner.RunWith(classOf[org.scalatest.junit.JUnitRunner])
class ScatterGatherFirstCompletedSpec extends AkkaSpec with DefaultTimeout with ImplicitSender {
  import ScatterGatherFirstCompletedSpec._

  "Scatter-gather group" must {

    "deliver a broadcast message using the !" in {
      val doneLatch = new TestLatch(2)

      val counter1 = new AtomicInteger
      val actor1 = system.actorOf(Props(new Actor {
        def receive = {
          case "end"    ⇒ doneLatch.countDown()
          case msg: Int ⇒ counter1.addAndGet(msg)
        }
      }))

      val counter2 = new AtomicInteger
      val actor2 = system.actorOf(Props(new Actor {
        def receive = {
          case "end"    ⇒ doneLatch.countDown()
          case msg: Int ⇒ counter2.addAndGet(msg)
        }
      }))

      val paths = List(actor1, actor2).map(_.path.toString)
      val routedActor = system.actorOf(ScatterGatherFirstCompletedGroup(paths, within = 1.second).props())
      routedActor ! Broadcast(1)
      routedActor ! Broadcast("end")

      Await.ready(doneLatch, TestLatch.DefaultTimeout)

      counter1.get should be(1)
      counter2.get should be(1)
    }

    "return response, even if one of the actors has stopped" in {
      val shutdownLatch = new TestLatch(1)
      val actor1 = newActor(1, Some(shutdownLatch))
      val actor2 = newActor(14, Some(shutdownLatch))
      val paths = List(actor1, actor2).map(_.path.toString)
      val routedActor = system.actorOf(ScatterGatherFirstCompletedGroup(paths, within = 3.seconds).props())

      routedActor ! Broadcast(Stop(Some(1)))
      Await.ready(shutdownLatch, TestLatch.DefaultTimeout)
      Await.result(routedActor ? Broadcast(0), timeout.duration) should be(14)
    }

  }

}