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import scala.actors._
import scala.actors.migration._
import scala.concurrent.util.duration._
import scala.concurrent.{ Promise, Await }
object SillyActor {
val startPromise = Promise[Boolean]()
val ref = MigrationSystem.actorOf(Props(() => new SillyActor, "default-stash-dispatcher"))
}
/* PinS, Listing 32.1: A simple actor
*/
class SillyActor extends StashingActor {
def receive = { case _ => println("Why are you not dead"); context.stop(self) }
override def preStart() {
Await.ready(SillyActor.startPromise.future, 5 seconds)
for (i <- 1 to 5)
println("I'm acting!")
context.stop(self)
}
override def postStop() {
println("Post stop")
}
}
object SeriousActor {
val startPromise = Promise[Boolean]()
val ref = MigrationSystem.actorOf(Props(() => new SeriousActor, "default-stash-dispatcher"))
}
class SeriousActor extends StashingActor {
def receive = { case _ => println("Nop") }
override def preStart() {
Await.ready(SeriousActor.startPromise.future, 5 seconds)
for (i <- 1 to 5)
println("To be or not to be.")
context.stop(self)
}
}
/* PinS, Listing 32.3: An actor that calls react
*/
object NameResolver {
val ref = MigrationSystem.actorOf(Props(() => new NameResolver, "default-stash-dispatcher"))
}
class NameResolver extends StashingActor {
import java.net.{ InetAddress, UnknownHostException }
def receive = {
case (name: String, actor: ActorRef) =>
actor ! getIp(name)
case "EXIT" =>
println("Name resolver exiting.")
context.stop(self) // quit
case msg =>
println("Unhandled message: " + msg)
}
def getIp(name: String): Option[InetAddress] = {
try {
Some(InetAddress.getByName(name))
} catch {
case _: UnknownHostException => None
}
}
}
object Test extends App {
/* PinS, Listing 32.2: An actor that calls receive
*/
def makeEchoActor(): ActorRef = MigrationSystem.actorOf(Props(() => new StashingActor {
def receive = { // how to handle receive
case 'stop =>
context.stop(self)
case msg =>
println("received message: " + msg)
}
}, "default-stash-dispatcher"))
/* PinS, page 696
*/
def makeIntActor(): ActorRef = MigrationSystem.actorOf(Props(() => new StashingActor {
def receive = {
case x: Int => // I only want Ints
unstashAll()
println("Got an Int: " + x)
context.stop(self)
case _ => stash()
}
}, "default-stash-dispatcher"))
MigrationSystem.actorOf(Props(() => new StashingActor {
val silly = SillyActor.ref
override def preStart() {
context.watch(SillyActor.ref)
SillyActor.startPromise.success(true)
}
def receive = {
case Terminated(`silly`) =>
unstashAll()
val serious = SeriousActor.ref
context.watch(SeriousActor.ref)
SeriousActor.startPromise.success(true)
context.become {
case Terminated(`serious`) =>
val seriousPromise2 = Promise[Boolean]()
// PinS, page 694
val seriousActor2 = MigrationSystem.actorOf(Props(() => {
new StashingActor {
def receive = { case _ => context.stop(self) }
override def preStart() = {
for (i <- 1 to 5)
println("That is the question.")
seriousPromise2.success(true)
context.stop(self)
}
}
}, "default-stash-dispatcher"))
Await.ready(seriousPromise2.future, 5 seconds)
val echoActor = makeEchoActor()
context.watch(echoActor)
echoActor ! "hi there"
echoActor ! 15
echoActor ! 'stop
context.become {
case Terminated(_) =>
unstashAll()
val intActor = makeIntActor()
intActor ! "hello"
intActor ! math.Pi
// only the following send leads to output
intActor ! 12
context.unbecome()
context.unbecome()
context.stop(self)
case m =>
println("Stash 1 " + m)
stash(m)
}
case m =>
println("Stash 2 " + m)
stash(m)
}
case m =>
println("Stash 3 " + m)
stash(m)
}
}, "default-stash-dispatcher"))
}
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