actor-supervision.scala

import akka.actor._, concurrent.ExecutionContext.Implicits.global, concurrent.duration._

case object CreateChild
case object GetChildren
case object GetParent
case class Message(str:String, forward:Boolean=false)

class ChildActor extends Actor {
  def receive = {
    case msg: String => println(s"${context.self.path.name}: $msg")
    case GetParent => println(context.parent)
  }
}

class ParentActor extends Actor {
  var childCount = 0
  def receive = {
    case CreateChild =>
      context.actorOf(Props[ChildActor],name="child-"+childCount)
      childCount += 1
    case GetChildren => println(context.children)
    case Message(str,fwd) => if (fwd) { context.children.foreach(_ forward str) } else println(str)
  }
}

val system = ActorSystem()
val parent = system.actorOf(Props[ParentActor],"parent")
for (i <- 0 to 4) { parent ! CreateChild }


/* 
 Using schedulers for repeated callbacks
*/

def startAsync: Unit = {
  system.scheduler.schedule(0.seconds,1.8.seconds){ parent ! Message("hello",true) }
  system.scheduler.schedule(1.seconds,1.2.seconds){ parent ! Message("bye",true) }
  system.scheduler.schedule(0.seconds,2.3.seconds){ parent ! Message("ok",true) }
}

class TaskActor extends Actor {
  var count = 5
  override def preStart() = context.system.scheduler.scheduleOnce(1.second, self, "tick")
  def receive = {
    case "tick" =>
      if (count == 0) { println("done") }
      else { 
        context.system.scheduler.scheduleOnce(1.second, self, "tick")
        println(s"pending-$count")
        count -= 1
      }
  }
}