import java.util.concurrent._ import java.util.concurrent.atomic._ object Test { def main(args: Array[String]) { val n = 10000 val i = new AtomicInteger(n) val j = new AtomicInteger(n) val sum = new AtomicInteger val q = new scala.concurrent.SyncVar[Int] val producers = (1 to 3) map { z => new Thread { override def run() { var again = true while (again) { val x = i.getAndDecrement() if (x > 0) q put x else again = false } } } } val summers = (1 to 7) map { z => new Thread { override def run() { val x = j.decrementAndGet() if (x >= 0) { sum addAndGet q.take() } if (x > 0) { run() } else { // done } } } } summers foreach { _.start() } producers foreach { _.start() } summers foreach { _.join() } val got = sum.get val expected = (n + 1) * n / 2 println(got + " " + expected + " " + (got == expected)) producers foreach { _.join() } } } // vim: set ts=2 sw=2 et: