Scala example source code file (ExecutorScheduler.scala)

This example Scala source code file (ExecutorScheduler.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

boolean, callable, executorscheduler, executorscheduler, executorservice, executorservice, ischeduler, runcallable, runnable, runnable, thread, threading, threadpoolrunner, threads, unit, unit

The Scala ExecutorScheduler.scala source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2005-2011, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */


package scala.actors
package scheduler

import java.util.concurrent.{Callable, ExecutorService}
import scala.concurrent.ThreadPoolRunner

/**
 * The <code>ExecutorScheduler object is used to create
 * <code>ExecutorScheduler instances.
 *
 * @author Philipp Haller
 */
object ExecutorScheduler {

  private def start(sched: ExecutorScheduler): ExecutorScheduler = {
    sched.start()
    sched
  }

  /** Creates an <code>ExecutorScheduler using the provided
   *  <code>ExecutorService.
   *
   *  @param  exec the executor to use
   *  @return      the scheduler
   */
  def apply(exec: ExecutorService): ExecutorScheduler =
    start(new ExecutorScheduler {
      val executor: ExecutorService = exec
    })

  /** Creates an <code>ExecutorScheduler using the provided
   *  <code>ExecutorService.
   *
   *  @param  exec the executor to use
   *  @param  term whether the scheduler should automatically terminate
   *  @return      the scheduler
   */
  def apply(exec: ExecutorService, term: Boolean): ExecutorScheduler =
    start(new ExecutorScheduler {
      val executor: ExecutorService = exec
      override val terminate = term
    })

}

/**
 * The <code>ExecutorScheduler class uses an
 * <code>ExecutorService to execute Actors.
 *
 * @author Philipp Haller
 */
trait ExecutorScheduler extends Thread
                        with IScheduler with TerminationService
                        with ThreadPoolRunner {

  def execute(task: Runnable) {
    super[ThreadPoolRunner].execute(task.asInstanceOf[Task[Unit]])
  }

  private class RunCallable(fun: => Unit) extends Callable[Unit] with Runnable {
    def call() { fun }
    def run() { fun }
  }

  /** Submits a closure for execution.
   *
   *  @param  fun  the closure to be executed
   */
  override def execute(fun: => Unit) {
    super[ThreadPoolRunner].execute((new RunCallable(fun)).asInstanceOf[Task[Unit]])
  }

  /** This method is called when the scheduler shuts down.
   */
  def onShutdown(): Unit =
    executor.shutdown()

  /** The scheduler is active if the underlying <code>ExecutorService
   *  has not been shut down.
   */
  def isActive =
    (executor ne null) && !executor.isShutdown

}