Prepared actors hierarchy for migration.

Internal nodes added so methods relevant to akka can be overridden.

Review by: @phaller

1 files changed, 10 insertions, 474 deletions

diff --git a/src/actors/scala/actors/Actor.scala b/src/actors/scala/actors/Actor.scala
index b746f68268..aab533ae8d 100644
--- a/src/actors/scala/actors/Actor.scala
+++ b/src/actors/scala/actors/Actor.scala
@@ -46,7 +46,7 @@ object Actor extends Combinators {
         Terminated = Value
   }
 
-  private[actors] val tl = new ThreadLocal[ReplyReactor]
+  private[actors] val tl = new ThreadLocal[InternalReplyReactor]
 
   // timer thread runs as daemon
   private[actors] val timer = new Timer(true)
@@ -59,15 +59,15 @@ object Actor extends Combinators {
    *
    * @return returns the currently executing actor.
    */
-  def self: Actor = self(Scheduler)
+  def self: Actor = self(Scheduler).asInstanceOf[Actor]
 
-  private[actors] def self(sched: IScheduler): Actor =
-    rawSelf(sched).asInstanceOf[Actor]
+  private[actors] def self(sched: IScheduler): InternalActor =
+    rawSelf(sched).asInstanceOf[InternalActor]
 
-  private[actors] def rawSelf: ReplyReactor =
+  private[actors] def rawSelf: InternalReplyReactor =
     rawSelf(Scheduler)
 
-  private[actors] def rawSelf(sched: IScheduler): ReplyReactor = {
+  private[actors] def rawSelf(sched: IScheduler): InternalReplyReactor = {
     val s = tl.get
     if (s eq null) {
       val r = new ActorProxy(Thread.currentThread, sched)
@@ -245,7 +245,7 @@ object Actor extends Combinators {
   def eventloop(f: PartialFunction[Any, Unit]): Nothing =
     rawSelf.react(new RecursiveProxyHandler(rawSelf, f))
 
-  private class RecursiveProxyHandler(a: ReplyReactor, f: PartialFunction[Any, Unit])
+  private class RecursiveProxyHandler(a: InternalReplyReactor, f: PartialFunction[Any, Unit])
           extends scala.runtime.AbstractPartialFunction[Any, Unit] {
     def _isDefinedAt(m: Any): Boolean =
       true // events are immediately removed from the mailbox
@@ -259,7 +259,7 @@ object Actor extends Combinators {
    * Returns the actor which sent the last received message.
    */
   def sender: OutputChannel[Any] =
-    rawSelf.sender
+    rawSelf.internalSender
 
   /**
    * Sends `msg` to the actor waiting in a call to `!?`.
@@ -302,7 +302,7 @@ object Actor extends Combinators {
     def andThen[b](other: => b): Unit
   }
 
-  implicit def mkBody[a](body: => a) = new Body[a] {
+  implicit def mkBody[a](body: => a) = new InternalActor.Body[a] {
     def andThen[b](other: => b): Unit = rawSelf.seq(body, other)
   }
 
@@ -397,476 +397,12 @@ object Actor extends Combinators {
  *  @define channel actor's mailbox
  */
 @SerialVersionUID(-781154067877019505L)
-trait Actor extends AbstractActor with ReplyReactor with ActorCanReply with InputChannel[Any] with Serializable {
-
-  /* The following two fields are only used when the actor
-   * suspends by blocking its underlying thread, for example,
-   * when waiting in a receive or synchronous send.
-   */
-  @volatile
-  private var isSuspended = false
-
-  /* This field is used to communicate the received message from
-   * the invocation of send to the place where the thread of
-   * the receiving actor resumes inside receive/receiveWithin.
-   */
-  @volatile
-  private var received: Option[Any] = None
-
-  protected[actors] override def scheduler: IScheduler = Scheduler
-
-  private[actors] override def startSearch(msg: Any, replyTo: OutputChannel[Any], handler: PartialFunction[Any, Any]) =
-    if (isSuspended) {
-      () => synchronized {
-        mailbox.append(msg, replyTo)
-        resumeActor()
-      }
-    } else super.startSearch(msg, replyTo, handler)
-
-  // we override this method to check `shouldExit` before suspending
-  private[actors] override def searchMailbox(startMbox: MQueue[Any],
-                                             handler: PartialFunction[Any, Any],
-                                             resumeOnSameThread: Boolean) {
-    var tmpMbox = startMbox
-    var done = false
-    while (!done) {
-      val qel = tmpMbox.extractFirst((msg: Any, replyTo: OutputChannel[Any]) => {
-        senders = List(replyTo)
-        handler.isDefinedAt(msg)
-      })
-      if (tmpMbox ne mailbox)
-        tmpMbox.foreach((m, s) => mailbox.append(m, s))
-      if (null eq qel) {
-        synchronized {
-          // in mean time new stuff might have arrived
-          if (!sendBuffer.isEmpty) {
-            tmpMbox = new MQueue[Any]("Temp")
-            drainSendBuffer(tmpMbox)
-            // keep going
-          } else {
-            // very important to check for `shouldExit` at this point
-            // since linked actors might have set it after we checked
-            // last time (e.g., at the beginning of `react`)
-            if (shouldExit) exit()
-            waitingFor = handler
-            // see Reactor.searchMailbox
-            throw Actor.suspendException
-          }
-        }
-      } else {
-        resumeReceiver((qel.msg, qel.session), handler, resumeOnSameThread)
-        done = true
-      }
-    }
-  }
-
-  private[actors] override def makeReaction(fun: () => Unit, handler: PartialFunction[Any, Any], msg: Any): Runnable =
-    new ActorTask(this, fun, handler, msg)
-
-  /** See the companion object's `receive` method. */
-  def receive[R](f: PartialFunction[Any, R]): R = {
-    assert(Actor.self(scheduler) == this, "receive from channel belonging to other actor")
-
-    synchronized {
-      if (shouldExit) exit() // links
-      drainSendBuffer(mailbox)
-    }
-
-    var done = false
-    while (!done) {
-      val qel = mailbox.extractFirst((m: Any, replyTo: OutputChannel[Any]) => {
-        senders = replyTo :: senders
-        val matches = f.isDefinedAt(m)
-        senders = senders.tail
-        matches
-      })
-      if (null eq qel) {
-        synchronized {
-          // in mean time new stuff might have arrived
-          if (!sendBuffer.isEmpty) {
-            drainSendBuffer(mailbox)
-            // keep going
-          } else {
-            waitingFor = f
-            isSuspended = true
-            scheduler.managedBlock(blocker)
-            drainSendBuffer(mailbox)
-            // keep going
-          }
-        }
-      } else {
-        received = Some(qel.msg)
-        senders = qel.session :: senders
-        done = true
-      }
-    }
-
-    val result = f(received.get)
-    received = None
-    senders = senders.tail
-    result
-  }
-
-  /** See the companion object's `receiveWithin` method. */
-  def receiveWithin[R](msec: Long)(f: PartialFunction[Any, R]): R = {
-    assert(Actor.self(scheduler) == this, "receive from channel belonging to other actor")
-
-    synchronized {
-      if (shouldExit) exit() // links
-      drainSendBuffer(mailbox)
-    }
-
-    // first, remove spurious TIMEOUT message from mailbox if any
-    mailbox.extractFirst((m: Any, replyTo: OutputChannel[Any]) => m == TIMEOUT)
-
-    val receiveTimeout = () => {
-      if (f.isDefinedAt(TIMEOUT)) {
-        received = Some(TIMEOUT)
-        senders = this :: senders
-      } else
-        sys.error("unhandled timeout")
-    }
-
-    var done = false
-    while (!done) {
-      val qel = mailbox.extractFirst((m: Any, replyTo: OutputChannel[Any]) => {
-        senders = replyTo :: senders
-        val matches = f.isDefinedAt(m)
-        senders = senders.tail
-        matches
-      })
-      if (null eq qel) {
-        val todo = synchronized {
-          // in mean time new stuff might have arrived
-          if (!sendBuffer.isEmpty) {
-            drainSendBuffer(mailbox)
-            // keep going
-            () => {}
-          } else if (msec == 0L) {
-            done = true
-            receiveTimeout
-          } else {
-            if (onTimeout.isEmpty) {
-              if (!f.isDefinedAt(TIMEOUT))
-                sys.error("unhandled timeout")
-
-              val thisActor = this
-              onTimeout = Some(new TimerTask {
-                def run() {
-                  thisActor.send(TIMEOUT, thisActor)
-                }
-              })
-              Actor.timer.schedule(onTimeout.get, msec)
-            }
-
-            // It is possible that !onTimeout.isEmpty, but TIMEOUT is not yet in mailbox
-            // See SI-4759
-            waitingFor = f
-            received = None
-            isSuspended = true
-            scheduler.managedBlock(blocker)
-            drainSendBuffer(mailbox)
-            // keep going
-            () => {}
-          }
-        }
-        todo()
-      } else {
-        synchronized {
-          if (!onTimeout.isEmpty) {
-            onTimeout.get.cancel()
-            onTimeout = None
-          }
-        }
-        received = Some(qel.msg)
-        senders = qel.session :: senders
-        done = true
-      }
-    }
-
-    val result = f(received.get)
-    received = None
-    senders = senders.tail
-    result
-  }
-
-  /** See the companion object's `react` method. */
-  override def react(handler: PartialFunction[Any, Unit]): Nothing = {
-    synchronized {
-      if (shouldExit) exit()
-    }
-    super.react(handler)
-  }
-
-  /** See the companion object's `reactWithin` method. */
-  override def reactWithin(msec: Long)(handler: PartialFunction[Any, Unit]): Nothing = {
-    synchronized {
-      if (shouldExit) exit()
-    }
-    super.reactWithin(msec)(handler)
-  }
-
-  /** Receives the next message from the mailbox */
-  def ? : Any = receive {
-    case x => x
-  }
-
-  // guarded by lock of this
-  // never throws SuspendActorControl
-  private[actors] override def scheduleActor(f: PartialFunction[Any, Any], msg: Any) =
-    if (f eq null) {
-      // do nothing (timeout is handled instead)
-    }
-    else {
-      val task = new ActorTask(this, null, f, msg)
-      scheduler executeFromActor task
-    }
-
-  /* Used for notifying scheduler when blocking inside receive/receiveWithin. */
-  private object blocker extends scala.concurrent.ManagedBlocker {
-    def block() = {
-      Actor.this.suspendActor()
-      true
-    }
-    def isReleasable =
-      !Actor.this.isSuspended
-  }
-
-  private def suspendActor() = synchronized {
-    while (isSuspended) {
-      try {
-        wait()
-      } catch {
-        case _: InterruptedException =>
-      }
-    }
-    // links: check if we should exit
-    if (shouldExit) exit()
-  }
-
-  private def resumeActor() {
-    isSuspended = false
-    notify()
-  }
-
-  private[actors] override def exiting = synchronized {
-    _state == Actor.State.Terminated
-  }
-
-  // guarded by this
-  private[actors] override def dostart() {
-    // Reset various flags.
-    //
-    // Note that we do *not* reset `trapExit`. The reason is that
-    // users should be able to set the field in the constructor
-    // and before `act` is called.
-    exitReason = 'normal
-    shouldExit = false
-
-    super.dostart()
-  }
+trait Actor extends InternalActor with ReplyReactor {
 
   override def start(): Actor = synchronized {
     super.start()
     this
   }
 
-  /** State of this actor */
-  override def getState: Actor.State.Value = synchronized {
-    if (isSuspended) {
-      if (onTimeout.isEmpty)
-        Actor.State.Blocked
-      else
-        Actor.State.TimedBlocked
-    } else
-      super.getState
-  }
-
-  // guarded by this
-  private[actors] var links: List[AbstractActor] = Nil
-
-  /**
-   * Links `self` to actor `to`.
-   *
-   * @param to the actor to link to
-   * @return   the parameter actor
-   */
-  def link(to: AbstractActor): AbstractActor = {
-    assert(Actor.self(scheduler) == this, "link called on actor different from self")
-    this linkTo to
-    to linkTo this
-    to
-  }
-
-  /**
-   * Links `self` to the actor defined by `body`.
-   *
-   * @param body the body of the actor to link to
-   * @return     the parameter actor
-   */
-  def link(body: => Unit): Actor = {
-    assert(Actor.self(scheduler) == this, "link called on actor different from self")
-    val a = new Actor {
-      def act() = body
-      override final val scheduler: IScheduler = Actor.this.scheduler
-    }
-    link(a)
-    a.start()
-    a
-  }
-
-  private[actors] def linkTo(to: AbstractActor) = synchronized {
-    links = to :: links
-  }
-
-  /**
-   * Unlinks `self` from actor `from`.
-   */
-  def unlink(from: AbstractActor) {
-    assert(Actor.self(scheduler) == this, "unlink called on actor different from self")
-    this unlinkFrom from
-    from unlinkFrom this
-  }
-
-  private[actors] def unlinkFrom(from: AbstractActor) = synchronized {
-    links = links.filterNot(from.==)
-  }
-
-  @volatile
-  var trapExit = false
-  // guarded by this
-  private var exitReason: AnyRef = 'normal
-  // guarded by this
-  private[actors] var shouldExit = false
-
-  /**
-   * Terminates execution of `self` with the following effect on
-   * linked actors:
-   *
-   * For each linked actor `a` with `trapExit` set to `'''true'''`,
-   * send message `Exit(self, reason)` to `a`.
-   *
-   * For each linked actor `a` with `trapExit` set to `'''false'''`
-   * (default), call `a.exit(reason)` if `reason != 'normal`.
-   */
-  protected[actors] def exit(reason: AnyRef): Nothing = {
-    synchronized {
-      exitReason = reason
-    }
-    exit()
-  }
-
-  /**
-   * Terminates with exit reason `'normal`.
-   */
-  protected[actors] override def exit(): Nothing = {
-    val todo = synchronized {
-      if (!links.isEmpty)
-        exitLinked()
-      else
-        () => {}
-    }
-    todo()
-    super.exit()
-  }
-
-  // Assume !links.isEmpty
-  // guarded by this
-  private[actors] def exitLinked(): () => Unit = {
-    _state = Actor.State.Terminated
-    // reset waitingFor, otherwise getState returns Suspended
-    waitingFor = Reactor.waitingForNone
-    // remove this from links
-    val mylinks = links.filterNot(this.==)
-    // unlink actors
-    mylinks.foreach(unlinkFrom(_))
-    // return closure that locks linked actors
-    () => {
-      mylinks.foreach((linked: AbstractActor) => {
-        linked.synchronized {
-          if (!linked.exiting) {
-            linked.unlinkFrom(this)
-            linked.exit(this, exitReason)
-          }
-        }
-      })
-    }
-  }
-
-  // Assume !links.isEmpty
-  // guarded by this
-  private[actors] def exitLinked(reason: AnyRef): () => Unit = {
-    exitReason = reason
-    exitLinked()
-  }
-
-  // Assume !this.exiting
-  private[actors] def exit(from: AbstractActor, reason: AnyRef) {
-    if (trapExit) {
-      this ! Exit(from, reason)
-    }
-    else if (reason != 'normal)
-      synchronized {
-        shouldExit = true
-        exitReason = reason
-        // resume this Actor in a way that
-        // causes it to exit
-        // (because shouldExit == true)
-        if (isSuspended)
-          resumeActor()
-        else if (waitingFor ne Reactor.waitingForNone) {
-          waitingFor = Reactor.waitingForNone
-          // it doesn't matter what partial function we are passing here
-          scheduleActor(waitingFor, null)
-          /* Here we should not throw a SuspendActorControl,
-             since the current method is called from an actor that
-             is in the process of exiting.
-
-             Therefore, the contract for scheduleActor is that
-             it never throws a SuspendActorControl.
-           */
-        }
-      }
-  }
-
-  /** Requires qualified private, because `RemoteActor` must
-   * register a termination handler.
-   */
-  private[actors] def onTerminate(f: => Unit) {
-    scheduler.onTerminate(this) { f }
-  }
 }
 
-
-/**
- *    Used as the timeout pattern in
- *    <a href="Actor.html#receiveWithin(Long)" target="contentFrame">
- *    <code>receiveWithin</code></a> and
- *    <a href="Actor.html#reactWithin(Long)" target="contentFrame">
- *    <code>reactWithin</code></a>.
- *
- * @example {{{
- *    receiveWithin(500) {
- *      case (x, y) => ...
- *      case TIMEOUT => ...
- *    }
- * }}}
- *
- *  @author Philipp Haller
- */
-case object TIMEOUT
-
-
-/** Sent to an actor with `trapExit` set to `'''true'''` whenever one of its
- *  linked actors terminates.
- *
- *  @param from   the actor that terminated
- *  @param reason the reason that caused the actor to terminate
- */
-case class Exit(from: AbstractActor, reason: AnyRef)
-
-/** Manages control flow of actor executions.
- *
- * @author Philipp Haller
- */
-private[actors] class SuspendActorControl extends ControlThrowable