Scala example source code file (ThreadRunner.scala)

This example Scala source code file (ThreadRunner.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

a, a, either, future, future, left, managedblocker, runnable, s, s, t, task, task, threadrunner

The Scala ThreadRunner.scala source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2011, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */



package scala.concurrent

import java.lang.Thread

/** The <code>ThreadRunner trait...
 *  
 *  @author Philipp Haller
 */
class ThreadRunner extends FutureTaskRunner {

  type Task[T] = () => T
  type Future[T] = () => T

  implicit def functionAsTask[S](fun: () => S): Task[S] = fun
  implicit def futureAsFunction[S](x: Future[S]): () => S = x

  /* If expression computed successfully return it in `Right`,
   * otherwise return exception in `Left`.
   */
  private def tryCatch[A](body: => A): Either[Exception, A] =
    try Right(body) catch {
      case ex: Exception => Left(ex)
    }

  def execute[S](task: Task[S]) {
    val runnable = new Runnable {
      def run() { tryCatch(task()) }
    }
    (new Thread(runnable)).start()
  }

  def submit[S](task: Task[S]): Future[S] = {
    val result = new SyncVar[Either[Exception, S]]
    val runnable = new Runnable {
      def run() { result set tryCatch(task()) }
    }
    (new Thread(runnable)).start()
    () => result.get.fold[S](throw _, identity _)
  }

  def managedBlock(blocker: ManagedBlocker) {
    blocker.block()
  }

  def shutdown() {
    // do nothing
  }

}