docs/examples/actors/Message.scala


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41

// Modified by Philipp Haller to use Scala's event-based actors.
package examples.actors

import scala.actors._
import scala.actors.Actor._

object Message {
  def main(args: Array[String]) = {
    val n = try {
      Integer.parseInt(args(0))
    }
    catch {
      case _ =>
        scala.Console.println("Usage: examples.actors.Message <n>")
        Predef.exit
    }
    val nActors = 500
    val finalSum = n * nActors
    Scheduler.impl = new SingleThreadedScheduler

    def beh(next: Actor, sum: int): unit =
      react {
        case value: int =>
          val j = value + 1; val nsum = sum + j
          if (next == null && nsum >= finalSum) {
            Console.println(nsum)
            System.exit(0)
          }
          else {
            if (next != null) next ! j
            beh(next, nsum)
          }
      }

    def actorChain(i: Int, a: Actor): Actor =
      if (i > 0) actorChain(i-1, actor(beh(a, 0))) else a

    val firstActor = actorChain(nActors, null)
    var i = n; while (i > 0) { firstActor ! 0; i = i-1 }
  }
}