summaryrefslogtreecommitdiff
path: root/docs/examples/computeserver.scala
blob: 788be284d1e45794d4b1f58dd271d86197ced6fd (plain) (blame)
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
42
43
44
45
46
47
48
49
50
51
52
53
54
package examples

import concurrent._, concurrent.ops._

class ComputeServer(n: Int) {

  private trait Job {
    type t
    def task: t
    def ret(x: t): Unit
  }

  private val openJobs = new Channel[Job]()

  private def processor(i: Int) {
    while (true) {
      val job = openJobs.read
      println("read a job")
      job.ret(job.task)
    }
  }

  def future[a](p: => a): () => a = {
    val reply = new SyncVar[a]()
    openJobs.write{
      new Job {
        type t = a
        def task = p
        def ret(x: a) = reply.set(x)
      }
    }
    () => reply.get
  }

  //spawn(replicate(0, n) { processor })
  spawn((0 until n).par foreach { processor })
}

object computeserver extends App {

  def kill(delay: Int) = new java.util.Timer().schedule(
    new java.util.TimerTask {
      override def run() = {
        println("[killed]")
        sys exit 0
      }
    },
    delay) // in milliseconds

  val server = new ComputeServer(1)
  val f = server.future(42)
  println(f())
  kill(10000)
}