Scala example source code file (ReactorTask.scala)

This example Scala source code file (ReactorTask.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

any, any, callable, callable, msg, msg, null, partialfunction, reactor, reactortask, recursiveaction, suspendactorcontrol, threading, threads, throwable, throwable

The Scala ReactorTask.scala source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2005-2011, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |                                         **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */


package scala.actors

import java.lang.Runnable
import java.util.concurrent.Callable

import scala.concurrent.forkjoin.RecursiveAction

/**
 *  @author Philipp Haller
 */
private[actors] class ReactorTask[Msg >: Null](var reactor: Reactor[Msg],
                                               var fun: () => Any,
                                               var handler: PartialFunction[Msg, Any],
                                               var msg: Msg)
  extends RecursiveAction with Callable[Unit] with Runnable {

  def run() {
    try {
      beginExecution()
      try {
        if (fun eq null)
          handler(msg)
        else
          fun()
      } catch {
        case _: KillActorControl =>
          // do nothing

        case e: Exception if reactor.exceptionHandler.isDefinedAt(e) =>
          reactor.exceptionHandler(e)
      }
      reactor.kill()
    }
    catch {
      case _: SuspendActorControl =>
        // do nothing (continuation is already saved)

      case e: Throwable =>
        terminateExecution(e)
        reactor.terminated()
        if (!e.isInstanceOf[Exception])
          throw e
    } finally {
      suspendExecution()
      this.reactor = null
      this.fun = null
      this.handler = null
      this.msg = null
    }
  }

  def call() = run()

  def compute() = run()

  protected def beginExecution() {}

  protected def suspendExecution() {}

  protected def terminateExecution(e: Throwable) {
    Console.err.println(reactor+": caught "+e)
    e.printStackTrace()
  }

}