timers and schedulers

attempt0.scala

import java.util.Date
import akka.actor._
import scala.concurrent.duration._

class TimedActor extends Actor with ActorLogging {
  override def receive: Receive = onTimer(None, None)

  def onTimer(msgReceived: Option[Date], oldTimer: Option[Cancellable]): Receive = {
    case msg =>
      oldTimer foreach (_.cancel())
    
      implicit val dispatcher = context.system.dispatcher
    
      val timer = context.system.scheduler.scheduleOnce(1 second) {
        msgReceived foreach { d =>
          if (new Date().getTime() - d.getTime() > 1000) {
            log.info("commiting suicide by poison pill")
            self ! PoisonPill
          }
        }
      }
    
      log.info(s"I've safely received: $msg")
      context.become(onTimer(Some(new Date), Some(timer)))
  }
}

object Exercise extends App {
  val system = ActorSystem("exercise")
  val timed = system.actorOf(Props[TimedActor](), "timedActor")
  
  (8 to 15) foreach { i =>
    system.log.info("sending message")
    timed ! s"Hello! [$i]"
    Thread.sleep(i * 100)
  }
  
  system.terminate()
}

attempt1.scala

import java.util.Date
import akka.actor._
import scala.concurrent.duration._

case object Timeout
class TimedActor extends Actor with ActorLogging with Timers {
  override def receive: Receive = {
    case Timeout =>
      log.info("Goodbye, world. You don't deserve me.")
      self ! PoisonPill
    
    case msg =>
      timers.cancel("timeout")
      log.info(s"I lived to receive another lovely message: $msg")
      timers.startSingleTimer("timeout", Timeout, 1 second)
  }
}

object Exercise extends App {
  val system = ActorSystem("exercise")
  val timed = system.actorOf(Props[TimedActor](), "timedActor")
  
  (8 to 15) foreach { i =>
    system.log.info("sending message")
    timed ! s"Hello! [$i]"
    Thread.sleep(i * 100)
  }
  
  system.terminate()
}