gistfile1.scala

  def spendNotMoreThan[T](time: Duration) = new {
    def on(op: => Result[T]): Result[T] = {
      var res:Result[T] = Empty
      var done = new AtomicBoolean(false)
      val nanos = time.toNanos
      val upto = System.nanoTime + nanos
      val worker = new Thread {
        override def run {
          res = op
          done.set(true)
        }
      }
      worker.setPriority(1)
      worker.start
      val sentinel = new Thread {
        override def run {
          while (!done.get && upto > System.nanoTime) try {
            Thread.sleep((upto - System.nanoTime + 999999) / 1000000) // java sleep does not use nanos
          }
          worker.stop
        }
      }
      sentinel.setPriority(5)
      sentinel.start
      sentinel.join
      if (done.get) res else Result.error(s"Timeout after $time")
    }
  }