/*  Title:      Pure/Concurrent/event_timer.scala
    Module:     PIDE
    Author:     Makarius
Initiate event after given point in time.
Note: events are run as synchronized action within a dedicated thread
and should finish quickly without further ado.
*/
package isabelle
import java.util.{Timer, TimerTask, Date}
object Event_Timer
{
  private lazy val event_timer = new Timer("event_timer", true)
  final class Request private[Event_Timer](val time: Time, task: TimerTask)
  {
    def cancel: Boolean = task.cancel
  }
  def request(time: Time)(event: => Unit): Request =
  {
    val task = new TimerTask { def run { event } }
    event_timer.schedule(task, new Date(time.ms))
    new Request(time, task)
  }
}