scala.actors.Reaction.scala Maven / Gradle / Ivy

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2005-2007, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |                                         **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */

// $Id: Reaction.scala 10241 2007-03-08 10:06:20Z phaller $


package scala.actors

import java.lang.{InterruptedException, Runnable}

/** 
 *    This exception is thrown whenever an actor exits.
 *    Its purpose is to let exit have
 *    return type Nothing.
 *  
 *
 * @version 0.9.4
 * @author Philipp Haller
 */
private[actors] class ExitActorException extends Throwable

/**
 * The abstract class Reaction associates
 * an instance of an Actor with a
 * java.lang.Runnable.
 *
 * @version 0.9.4
 * @author Philipp Haller
 */
private[actors] class Reaction(a: Actor,
                               f: PartialFunction[Any, Unit],
                               msg: Any) extends Runnable {
  def this(a: Actor) = this(a, null, null)

  def actor = a

  def run(): Unit = {
    val saved = Actor.tl.get.asInstanceOf[Actor]
    Actor.tl.set(a)
    Scheduler.unPendReaction
    a.isDetached = false
    try {
      try {
        if (a.shouldExit) // links
          a.exit()
        else {
          if (f == null)
            a.act()
          else
            f(msg)
          a.exit()
        }
      } catch {
        case _: ExitActorException =>
      }
    }
    catch {
      case _: SuspendActorException => {
        // do nothing (continuation is already saved)
      }
      case t: Throwable => {
        // links
        if (!a.links.isEmpty) {
          a.exitLinked(t)
        }
      }
    }
    Actor.tl.set(saved)
  }

}