unify sender/senderFuture into channel (++)

(squashed merge from the various bits and pieces already part of
release-1.2, everything related to Channel & Future)

akka-actor-tests/src/test/scala/akka/actor/actor/ActorFireForgetRequestReplySpec.scala

@@ -23,7 +23,7 @@ object ActorFireForgetRequestReplySpec {
       case "Send" ⇒
         self.reply("Reply")
       case "SendImplicit" ⇒
-        self.sender.get ! "ReplyImplicit"
+        self.channel ! "ReplyImplicit"
     }
   }
 

akka-actor-tests/src/test/scala/akka/actor/actor/ActorTimeoutSpec.scala

@@ -0,0 +1,55 @@
+/**
+ * Copyright (C) 2009-2011 Scalable Solutions AB <http://scalablesolutions.se>
+ */
+package akka.actor
+
+import org.scalatest.{ WordSpec, BeforeAndAfterAll }
+import org.scalatest.matchers.MustMatchers
+import akka.testkit.TestKit
+import akka.dispatch.FutureTimeoutException
+import akka.util.duration._
+
+class ActorTimeoutSpec
+  extends WordSpec
+  with BeforeAndAfterAll
+  with MustMatchers
+  with TestKit {
+
+  val echo = Actor.actorOf(new Actor {
+    def receive = {
+      case x ⇒
+    }
+  }).start()
+
+  val testTimeout = if (Actor.defaultTimeout.duration < 400.millis) 500 millis else 100 millis
+
+  override def afterAll { echo.stop() }
+
+  "An Actor-based Future" must {
+
+    "use the global default timeout if no implicit in scope" in {
+      echo.timeout = 12
+      within((Actor.TIMEOUT - 100).millis, (Actor.TIMEOUT + 300).millis) {
+        val f = echo ? "hallo"
+        intercept[FutureTimeoutException] { f.await }
+      }
+    }
+
+    "use implicitly supplied timeout" in {
+      implicit val timeout = Actor.Timeout(testTimeout)
+      within(testTimeout - 100.millis, testTimeout + 300.millis) {
+        val f = (echo ? "hallo").mapTo[String]
+        intercept[FutureTimeoutException] { f.await }
+        f.value must be(None)
+      }
+    }
+
+    "use explicitly supplied timeout" in {
+      within(testTimeout - 100.millis, testTimeout + 300.millis) {
+        (echo.?("hallo")(timeout = testTimeout)).as[String] must be(None)
+      }
+    }
+
+  }
+
+}

akka-actor-tests/src/test/scala/akka/actor/actor/Bench.scala

@@ -102,7 +102,7 @@ object Chameneos {
           }
         } else {
           waitingChameneo.foreach(_ ! Exit)
-          self.sender.get ! Exit
+          self.channel ! Exit
         }
     }
   }

akka-actor-tests/src/test/scala/akka/dispatch/MailboxConfigSpec.scala

@@ -4,7 +4,7 @@ import org.scalatest.matchers.MustMatchers
 import org.scalatest.{ BeforeAndAfterAll, BeforeAndAfterEach }
 import org.scalatest.junit.JUnitRunner
 import org.junit.runner.RunWith
-import akka.actor.{ Actor, ActorRegistry }
+import akka.actor.{ Actor, ActorRegistry, NullChannel }
 import akka.actor.Actor.{ actorOf }
 import java.util.concurrent.{ TimeUnit, CountDownLatch, BlockingQueue }
 import java.util.{ Queue }
@@ -84,7 +84,7 @@ abstract class MailboxSpec extends WordSpec with MustMatchers with BeforeAndAfte
     new MessageInvocation(
       actorOf(new Actor { //Dummy actor
         def receive = { case _ ⇒ }
-      }), msg, None, None)
+      }), msg, NullChannel)
   }
 
   def ensureInitialMailboxState(config: MailboxType, q: MessageQueue) {

akka-actor-tests/src/test/scala/akka/routing/RoutingSpec.scala

@@ -193,11 +193,11 @@ class RoutingSpec extends WordSpec with MustMatchers {
         }).start()
 
       val successes = TestLatch(2)
-      val successCounter = Some(actorOf(new Actor {
+      val successCounter = actorOf(new Actor {
         def receive = {
           case "success" ⇒ successes.countDown()
         }
-      }).start())
+      }).start()
 
       implicit val replyTo = successCounter
       pool ! "a"

akka-actor/src/main/scala/akka/actor/Actor.scala

@@ -24,6 +24,7 @@ import scala.reflect.BeanProperty
 import com.eaio.uuid.UUID
 
 import java.lang.reflect.InvocationTargetException
+import java.util.concurrent.TimeUnit
 
 /**
  * Life-cycle messages for the Actors
@@ -110,9 +111,6 @@ object Status {
  */
 object Actor extends ListenerManagement {
 
-  private[akka] val TIMEOUT = Duration(config.getInt("akka.actor.timeout", 5), TIME_UNIT).toMillis
-  private[akka] val SERIALIZE_MESSAGES = config.getBool("akka.actor.serialize-messages", false)
-
   /**
    * A Receive is a convenience type that defines actor message behavior currently modeled as
    * a PartialFunction[Any, Unit].
@@ -140,6 +138,20 @@ object Actor extends ListenerManagement {
     override def initialValue = Stack[ActorRef]()
   }
 
+  case class Timeout(duration: Duration) {
+    def this(timeout: Long) = this(Duration(timeout, TimeUnit.MILLISECONDS))
+    def this(length: Long, unit: TimeUnit) = this(Duration(length, unit))
+  }
+  object Timeout {
+    def apply(timeout: Long) = new Timeout(timeout)
+    def apply(length: Long, unit: TimeUnit) = new Timeout(length, unit)
+    implicit def durationToTimeout(duration: Duration) = new Timeout(duration)
+  }
+
+  private[akka] val TIMEOUT = Duration(config.getInt("akka.actor.timeout", 5), TIME_UNIT).toMillis
+  val defaultTimeout = Timeout(TIMEOUT)
+  private[akka] val SERIALIZE_MESSAGES = config.getBool("akka.actor.serialize-messages", false)
+
   /**
    * Handle to the ActorRegistry.
    */
@@ -495,14 +507,14 @@ trait Actor {
    */
   type Receive = Actor.Receive
 
-  /*
+  /**
    * Some[ActorRef] representation of the 'self' ActorRef reference.
    * <p/>
    * Mainly for internal use, functions as the implicit sender references when invoking
    * the 'forward' function.
    */
   @transient
-  implicit val someSelf: Some[ActorRef] = {
+  val someSelf: Some[ActorRef] = {
     val refStack = Actor.actorRefInCreation.get
     if (refStack.isEmpty) throw new ActorInitializationException(
       "ActorRef for instance of actor [" + getClass.getName + "] is not in scope." +
@@ -528,7 +540,7 @@ trait Actor {
    * Mainly for internal use, functions as the implicit sender references when invoking
    * one of the message send functions ('!', '!!' and '!!!').
    */
-  implicit def optionSelf: Option[ActorRef] = someSelf
+  def optionSelf: Option[ActorRef] = someSelf
 
   /**
    * The 'self' field holds the ActorRef for this actor.
@@ -558,7 +570,7 @@ trait Actor {
    * </pre>
    */
   @transient
-  val self: ScalaActorRef = someSelf.get
+  implicit val self: ScalaActorRef = someSelf.get
 
   /**
    * User overridable callback/setting.
@@ -645,8 +657,7 @@ trait Actor {
 
   private[akka] final def apply(msg: Any) = {
     if (msg.isInstanceOf[AnyRef] && (msg.asInstanceOf[AnyRef] eq null))
-      throw new InvalidMessageException("Message from [" + self.sender + "] to [" + self.toString + "] is null")
-
+      throw new InvalidMessageException("Message from [" + self.channel + "] to [" + self.toString + "] is null")
     val behaviorStack = self.hotswap
 
     msg match {
@@ -675,9 +686,9 @@ trait Actor {
       case Restart(reason)           ⇒ throw reason
       case Kill                      ⇒ throw new ActorKilledException("Kill")
       case PoisonPill ⇒
-        val f = self.senderFuture()
+        val ch = self.channel
         self.stop()
-        if (f.isDefined) f.get.completeWithException(new ActorKilledException("PoisonPill"))
+        ch.sendException(new ActorKilledException("PoisonPill"))
     }
   }
 

akka-actor/src/main/scala/akka/actor/ActorRef.scala

@@ -33,27 +33,6 @@ private[akka] object ActorRefInternals {
   object SHUTDOWN extends StatusType
 }
 
-/**
- * Abstraction for unification of sender and senderFuture for later reply.
- * Can be stored away and used at a later point in time.
- */
-abstract class Channel[T] {
-
-  /**
-   * Scala API. <p/>
-   * Sends the specified message to the channel.
-   */
-  def !(msg: T)
-
-  /**
-   * Java API. <p/>
-   * Sends the specified message to the channel.
-   */
-  def sendOneWay(msg: T) {
-    this.!(msg)
-  }
-}
-
 /**
  * ActorRef is an immutable and serializable handle to an Actor.
  * <p/>
@@ -86,7 +65,7 @@ abstract class Channel[T] {
  *
  * @author <a href="http://jonasboner.com">Jonas Bon&#233;r</a>
  */
-trait ActorRef extends ActorRefShared with java.lang.Comparable[ActorRef] with Serializable { scalaRef: ScalaActorRef ⇒
+trait ActorRef extends ActorRefShared with ForwardableChannel with java.lang.Comparable[ActorRef] with Serializable { scalaRef: ScalaActorRef ⇒
   // Only mutable for RemoteServer in order to maintain identity across nodes
   @volatile
   protected[akka] var _uuid = newUuid
@@ -241,40 +220,18 @@ trait ActorRef extends ActorRefShared with java.lang.Comparable[ActorRef] with S
     _uuid = uid
   }
 
-  /**
-   * Akka Java API. <p/>
-   * Sends a one-way asynchronous message. E.g. fire-and-forget semantics.
-   * <p/>
-   * <pre>
-   * actor.sendOneWay(message);
-   * </pre>
-   * <p/>
-   */
-  def sendOneWay(message: AnyRef): Unit = {
-    sendOneWay(message, null)
-  }
-
-  /**
-   * Akka Java API. <p/>
-   * Sends a one-way asynchronous message. E.g. fire-and-forget semantics.
-   * <p/>
-   * Allows you to pass along the sender of the message.
-   * <p/>
-   * <pre>
-   * actor.sendOneWay(message, context);
-   * </pre>
-   * <p/>
-   */
-  def sendOneWay(message: AnyRef, sender: ActorRef) {
-    this.!(message)(Option(sender))
-  }
-
   /**
    * Akka Java API. <p/>
    * @see sendRequestReply(message: AnyRef, timeout: Long, sender: ActorRef)
    * Uses the default timeout of the Actor (setTimeout()) and omits the sender reference
    */
-  def sendRequestReply(message: AnyRef): AnyRef = sendRequestReply(message, timeout, null)
+  def sendRequestReply(message: AnyRef): AnyRef = {
+    !!(message, timeout).getOrElse(throw new ActorTimeoutException(
+      "Message [" + message +
+        "]\n\tfrom [nowhere]\n\twith timeout [" + timeout +
+        "]\n\ttimed out."))
+      .asInstanceOf[AnyRef]
+  }
 
   /**
    * Akka Java API. <p/>
@@ -298,7 +255,7 @@ trait ActorRef extends ActorRefShared with java.lang.Comparable[ActorRef] with S
    * to send a reply message to the original sender. If not then the sender will block until the timeout expires.
    */
   def sendRequestReply(message: AnyRef, timeout: Long, sender: ActorRef): AnyRef = {
-    !!(message, timeout)(Option(sender)).getOrElse(throw new ActorTimeoutException(
+    ?(message)(sender, Actor.Timeout(timeout)).as[AnyRef].getOrElse(throw new ActorTimeoutException(
       "Message [" + message +
         "]\n\tfrom [" + (if (sender ne null) sender.address else "nowhere") +
         "]\n\twith timeout [" + timeout +
@@ -311,14 +268,14 @@ trait ActorRef extends ActorRefShared with java.lang.Comparable[ActorRef] with S
    * @see sendRequestReplyFuture(message: AnyRef, sender: ActorRef): Future[_]
    * Uses the Actors default timeout (setTimeout()) and omits the sender
    */
-  def sendRequestReplyFuture[T <: AnyRef](message: AnyRef): Future[T] = sendRequestReplyFuture(message, timeout, null).asInstanceOf[Future[T]]
+  def sendRequestReplyFuture(message: AnyRef): Future[Any] = ?(message)
 
   /**
    * Akka Java API. <p/>
    * @see sendRequestReplyFuture(message: AnyRef, sender: ActorRef): Future[_]
    * Uses the Actors default timeout (setTimeout())
    */
-  def sendRequestReplyFuture[T <: AnyRef](message: AnyRef, sender: ActorRef): Future[T] = sendRequestReplyFuture(message, timeout, sender).asInstanceOf[Future[T]]
+  def sendRequestReplyFuture(message: AnyRef, sender: ActorRef): Future[Any] = ?(message)(sender)
 
   /**
    *  Akka Java API. <p/>
@@ -331,7 +288,7 @@ trait ActorRef extends ActorRefShared with java.lang.Comparable[ActorRef] with S
    * If you are sending messages using <code>sendRequestReplyFuture</code> then you <b>have to</b> use <code>getContext().reply(..)</code>
    * to send a reply message to the original sender. If not then the sender will block until the timeout expires.
    */
-  def sendRequestReplyFuture[T <: AnyRef](message: AnyRef, timeout: Long, sender: ActorRef): Future[T] = !!!(message, timeout)(Option(sender)).asInstanceOf[Future[T]]
+  def sendRequestReplyFuture(message: AnyRef, timeout: Long, sender: ActorRef): Future[Any] = ?(message)(sender, Actor.Timeout(timeout))
 
   /**
    * Akka Java API. <p/>
@@ -339,7 +296,7 @@ trait ActorRef extends ActorRefShared with java.lang.Comparable[ActorRef] with S
    */
   def forward(message: AnyRef, sender: ActorRef) {
     if (sender eq null) throw new IllegalArgumentException("The 'sender' argument to 'forward' can't be null")
-    else forward(message)(Some(sender))
+    else forward(message)(sender)
   }
 
   /**
@@ -448,36 +405,36 @@ trait ActorRef extends ActorRefShared with java.lang.Comparable[ActorRef] with S
   /**
    * Abstraction for unification of sender and senderFuture for later reply
    */
-  def channel: Channel[Any] = {
-    if (senderFuture.isDefined) {
-      new Channel[Any] {
-        val future = senderFuture.get
-        def !(msg: Any) = future completeWithResult msg
-      }
-    } else if (sender.isDefined) {
-      val someSelf = Some(this)
-      new Channel[Any] {
-        val client = sender.get
-        def !(msg: Any) = client.!(msg)(someSelf)
-      }
-    } else throw new IllegalActorStateException("No channel available")
+  def channel: UntypedChannel = {
+    val msg = currentMessage
+    if (msg ne null) msg.channel
+    else NullChannel
   }
 
+  /*
+   * Implementation of ForwardableChannel
+   */
+
+  def sendException(ex: Throwable) {}
+  def isUsableOnlyOnce = false
+  def isUsable = true
+  def isReplyable = true
+  def canSendException = false
+
   /**
    * Java API. <p/>
    * Abstraction for unification of sender and senderFuture for later reply
    */
-  def getChannel: Channel[Any] = channel
+  def getChannel: UntypedChannel = channel
 
   protected[akka] def invoke(messageHandle: MessageInvocation)
 
-  protected[akka] def postMessageToMailbox(message: Any, senderOption: Option[ActorRef])
+  protected[akka] def postMessageToMailbox(message: Any, channel: UntypedChannel): Unit
 
-  protected[akka] def postMessageToMailboxAndCreateFutureResultWithTimeout[T](
+  protected[akka] def postMessageToMailboxAndCreateFutureResultWithTimeout(
     message: Any,
     timeout: Long,
-    senderOption: Option[ActorRef],
-    senderFuture: Option[Promise[T]]): Promise[T]
+    channel: UntypedChannel): Future[Any]
 
   protected[akka] def actorInstance: AtomicReference[Actor]
 
@@ -692,18 +649,19 @@ class LocalActorRef private[akka] (private[this] val actorFactory: () ⇒ Actor,
     _supervisor = sup
   }
 
-  protected[akka] def postMessageToMailbox(message: Any, senderOption: Option[ActorRef]) {
-    dispatcher dispatchMessage MessageInvocation(this, message, senderOption, None)
-  }
+  protected[akka] def postMessageToMailbox(message: Any, channel: UntypedChannel): Unit =
+    dispatcher dispatchMessage new MessageInvocation(this, message, channel)
 
-  protected[akka] def postMessageToMailboxAndCreateFutureResultWithTimeout[T](
+  protected[akka] def postMessageToMailboxAndCreateFutureResultWithTimeout(
     message: Any,
     timeout: Long,
-    senderOption: Option[ActorRef],
-    senderFuture: Option[Promise[T]]): Promise[T] = {
-    val future = if (senderFuture.isDefined) senderFuture else Some(new DefaultPromise[T](timeout))
-    dispatcher dispatchMessage MessageInvocation(this, message, senderOption, future.asInstanceOf[Some[Promise[Any]]])
-    future.get
+    channel: UntypedChannel): Future[Any] = {
+    val future = channel match {
+      case f: ActorPromise ⇒ f
+      case _               ⇒ new ActorPromise(timeout)
+    }
+    dispatcher dispatchMessage new MessageInvocation(this, message, future)
+    future
   }
 
   /**
@@ -888,7 +846,7 @@ class LocalActorRef private[akka] (private[this] val actorFactory: () ⇒ Actor,
     //Prevent any further messages to be processed until the actor has been restarted
     dispatcher.suspend(this)
 
-    senderFuture.foreach(_.completeWithException(reason))
+    channel.sendException(reason)
 
     if (supervisor.isDefined) notifySupervisorWithMessage(Exit(this, reason))
     else {
@@ -995,19 +953,28 @@ private[akka] case class RemoteActorRef private[akka] (
 
   start()
 
-  def postMessageToMailbox(message: Any, senderOption: Option[ActorRef]) {
-    Actor.remote.send[Any](message, senderOption, None, remoteAddress, timeout, true, this, loader)
+  def postMessageToMailbox(message: Any, channel: UntypedChannel): Unit = {
+    val chSender = channel match {
+      case ref: ActorRef ⇒ Some(ref)
+      case _             ⇒ None
+    }
+    Actor.remote.send[Any](message, chSender, None, remoteAddress, timeout, true, this, loader)
   }
 
-  def postMessageToMailboxAndCreateFutureResultWithTimeout[T](
+  def postMessageToMailboxAndCreateFutureResultWithTimeout(
     message: Any,
     timeout: Long,
-    senderOption: Option[ActorRef],
-    senderFuture: Option[Promise[T]]): Promise[T] = {
-    val future = Actor.remote.send[T](
-      message, senderOption, senderFuture,
-      remoteAddress, timeout, false, this, loader)
-    if (future.isDefined) future.get
+    channel: UntypedChannel): Future[Any] = {
+    val chSender = channel match {
+      case ref: ActorRef ⇒ Some(ref)
+      case _             ⇒ None
+    }
+    val chFuture = channel match {
+      case f: Promise[Any] ⇒ Some(f)
+      case _               ⇒ None
+    }
+    val future = Actor.remote.send[Any](message, chSender, chFuture, remoteAddress, timeout, false, this, loader)
+    if (future.isDefined) ActorPromise(future.get)
     else throw new IllegalActorStateException("Expected a future from remote call to actor " + toString)
   }
 
@@ -1096,7 +1063,7 @@ trait ActorRefShared {
  * There are implicit conversions in ../actor/Implicits.scala
  * from ActorRef -> ScalaActorRef and back
  */
-trait ScalaActorRef extends ActorRefShared { ref: ActorRef ⇒
+trait ScalaActorRef extends ActorRefShared with ForwardableChannel { ref: ActorRef ⇒
 
   /**
    * Address for actor, must be a unique one.
@@ -1134,20 +1101,28 @@ trait ScalaActorRef extends ActorRefShared { ref: ActorRef ⇒
    * The reference sender Actor of the last received message.
    * Is defined if the message was sent from another Actor, else None.
    */
+  @deprecated("will be removed in 2.0, use channel instead", "1.2")
   def sender: Option[ActorRef] = {
     val msg = currentMessage
     if (msg eq null) None
-    else msg.sender
+    else msg.channel match {
+      case ref: ActorRef ⇒ Some(ref)
+      case _             ⇒ None
+    }
   }
 
   /**
    * The reference sender future of the last received message.
    * Is defined if the message was sent with sent with '!!' or '!!!', else None.
    */
+  @deprecated("will be removed in 2.0, use channel instead", "1.2")
   def senderFuture(): Option[Promise[Any]] = {
     val msg = currentMessage
     if (msg eq null) None
-    else msg.senderFuture
+    else msg.channel match {
+      case f: ActorPromise ⇒ Some(f)
+      case _               ⇒ None
+    }
   }
 
   /**
@@ -1164,8 +1139,8 @@ trait ScalaActorRef extends ActorRefShared { ref: ActorRef ⇒
    * </pre>
    * <p/>
    */
-  def !(message: Any)(implicit sender: Option[ActorRef] = None) {
-    if (isRunning) postMessageToMailbox(message, sender)
+  def !(message: Any)(implicit channel: UntypedChannel = NullChannel): Unit = {
+    if (isRunning) postMessageToMailbox(message, channel)
     else throw new ActorInitializationException(
       "Actor has not been started, you need to invoke 'actor.start()' before using it")
   }
@@ -1182,9 +1157,10 @@ trait ScalaActorRef extends ActorRefShared { ref: ActorRef ⇒
    * If you are sending messages using <code>!!</code> then you <b>have to</b> use <code>self.reply(..)</code>
    * to send a reply message to the original sender. If not then the sender will block until the timeout expires.
    */
-  def !!(message: Any, timeout: Long = this.timeout)(implicit sender: Option[ActorRef] = None): Option[Any] = {
+  @deprecated("use `(actor ? msg).as[T]` instead", "1.2")
+  def !!(message: Any, timeout: Long = this.timeout)(implicit channel: UntypedChannel = NullChannel): Option[Any] = {
     if (isRunning) {
-      val future = postMessageToMailboxAndCreateFutureResultWithTimeout[Any](message, timeout, sender, None)
+      val future = postMessageToMailboxAndCreateFutureResultWithTimeout(message, timeout, channel)
 
       try { future.await.resultOrException } catch { case e: FutureTimeoutException ⇒ None }
     } else throw new ActorInitializationException(
@@ -1200,8 +1176,15 @@ trait ScalaActorRef extends ActorRefShared { ref: ActorRef ⇒
    * If you are sending messages using <code>!!!</code> then you <b>have to</b> use <code>self.reply(..)</code>
    * to send a reply message to the original sender. If not then the sender will block until the timeout expires.
    */
-  def !!![T](message: Any, timeout: Long = this.timeout)(implicit sender: Option[ActorRef] = None): Future[T] = {
-    if (isRunning) postMessageToMailboxAndCreateFutureResultWithTimeout[T](message, timeout, sender, None)
+  @deprecated("return type is an illusion, use the more honest ? method", "1.2")
+  def !!![T](message: Any, timeout: Long = this.timeout)(implicit channel: UntypedChannel = NullChannel): Future[T] =
+    this.?(message)(channel, Actor.Timeout(timeout)).asInstanceOf[Future[T]]
+
+  /**
+   * Sends a message asynchronously, returning a future which may eventually hold the reply.
+   */
+  def ?(message: Any)(implicit channel: UntypedChannel = NullChannel, timeout: Actor.Timeout = Actor.defaultTimeout): Future[Any] = {
+    if (isRunning) postMessageToMailboxAndCreateFutureResultWithTimeout(message, timeout.duration.toMillis, channel)
     else throw new ActorInitializationException(
       "Actor has not been started, you need to invoke 'actor.start()' before using it")
   }
@@ -1211,12 +1194,9 @@ trait ScalaActorRef extends ActorRefShared { ref: ActorRef ⇒
    * <p/>
    * Works with '!', '!!' and '!!!'.
    */
-  def forward(message: Any)(implicit sender: Some[ActorRef]) = {
+  def forward(message: Any)(implicit channel: ForwardableChannel) = {
     if (isRunning) {
-      if (sender.get.senderFuture.isDefined)
-        postMessageToMailboxAndCreateFutureResultWithTimeout(message, timeout, sender.get.sender, sender.get.senderFuture)
-      else
-        postMessageToMailbox(message, sender.get.sender)
+      postMessageToMailbox(message, channel.channel)
     } else throw new ActorInitializationException("Actor has not been started, you need to invoke 'actor.start()' before using it")
   }
 
@@ -1226,14 +1206,7 @@ trait ScalaActorRef extends ActorRefShared { ref: ActorRef ⇒
    * <p/>
    * Throws an IllegalStateException if unable to determine what to reply to.
    */
-  def reply(message: Any) {
-    if (!reply_?(message)) throw new IllegalActorStateException(
-      "\n\tNo sender in scope, can't reply. " +
-        "\n\tYou have probably: " +
-        "\n\t\t1. Sent a message to an Actor from an instance that is NOT an Actor." +
-        "\n\t\t2. Invoked a method on an TypedActor from an instance NOT an TypedActor." +
-        "\n\tElse you might want to use 'reply_?' which returns Boolean(true) if succes and Boolean(false) if no sender in scope")
-  }
+  def reply(message: Any) = channel.!(message)(this)
 
   /**
    * Use <code>reply_?(..)</code> to reply with a message to the original sender of the message currently
@@ -1241,16 +1214,7 @@ trait ScalaActorRef extends ActorRefShared { ref: ActorRef ⇒
    * <p/>
    * Returns true if reply was sent, and false if unable to determine what to reply to.
    */
-  def reply_?(message: Any): Boolean = {
-    if (senderFuture.isDefined) {
-      senderFuture.get completeWithResult message
-      true
-    } else if (sender.isDefined) {
-      //TODO: optimize away this allocation, perhaps by having implicit self: Option[ActorRef] in signature
-      sender.get.!(message)(Some(this))
-      true
-    } else false
-  }
+  def reply_?(message: Any): Boolean = channel.safe_!(message)(this)
 }
 
 case class SerializedActorRef(val uuid: Uuid,

akka-actor/src/main/scala/akka/actor/Channel.scala

@@ -0,0 +1,173 @@
+/**
+ *  Copyright (C) 2009-2011 Scalable Solutions AB <http://scalablesolutions.se>
+ */
+
+package akka.actor
+
+/**
+ * Abstraction for unification of sender and senderFuture for later reply.
+ * Can be stored away and used at a later point in time.
+ *
+ * Channel cannot be contravariant because of Future providing its value in
+ * covariant position.
+ *
+ * The possible reply channel which can be passed into ! and safe_! is always
+ * untyped, as there is no way to utilize its real static type without
+ * requiring runtime-costly manifests.
+ */
+trait Channel[T] {
+
+  /**
+   * Scala API. <p/>
+   * Sends the specified message to the channel.
+   */
+  def !(msg: T)(implicit channel: UntypedChannel = NullChannel): Unit
+
+  /**
+   * Try to send an exception. Not all channel types support this, one notable
+   * positive example is Future. Failure to send is silent.
+   */
+  def sendException(ex: Throwable): Unit
+
+  /**
+   * Scala API.<p/>
+   * Try to send message to the channel, return whether successful.
+   */
+  def safe_!(msg: T)(implicit channel: UntypedChannel = NullChannel): Boolean
+
+  /**
+   * Indicates whether this channel may be used only once, e.g. a Future.
+   */
+  def isUsableOnlyOnce: Boolean
+
+  /**
+   * Indicates whether this channel may still be used (only useful if
+   * isUsableOnlyOnce returns true).
+   */
+  def isUsable: Boolean
+
+  /**
+   * Indicates whether this channel carries reply information, e.g. an
+   * ActorRef.
+   */
+  def isReplyable: Boolean
+
+  /**
+   * Indicates whether this channel is capable of sending exceptions to its
+   * recipient.
+   */
+  def canSendException: Boolean
+
+  /**
+   * Java API.<p/>
+   * Sends the specified message to the channel, i.e. fire-and-forget semantics.<p/>
+   * <pre>
+   * actor.sendOneWay(message);
+   * </pre>
+   */
+  def sendOneWay(msg: T): Unit = this.!(msg)
+
+  /**
+   * Java API. <p/>
+   * Sends the specified message to the channel, i.e. fire-and-forget
+   * semantics, including the sender reference if possible (not supported on
+   * all channels).<p/>
+   * <pre>
+   * actor.sendOneWay(message, context);
+   * </pre>
+   */
+  def sendOneWay(msg: T, sender: UntypedChannel): Unit = this.!(msg)(sender)
+
+  /**
+   * Java API.<p/>
+   * Try to send the specified message to the channel, i.e. fire-and-forget semantics.<p/>
+   * <pre>
+   * actor.sendOneWay(message);
+   * </pre>
+   */
+  def sendOneWaySafe(msg: T): Boolean = this.safe_!(msg)
+
+  /**
+   * Java API. <p/>
+   * Try to send the specified message to the channel, i.e. fire-and-forget
+   * semantics, including the sender reference if possible (not supported on
+   * all channels).<p/>
+   * <pre>
+   * actor.sendOneWay(message, context);
+   * </pre>
+   */
+  def sendOneWaySafe(msg: T, sender: UntypedChannel): Boolean = this.safe_!(msg)(sender)
+
+}
+
+/**
+ * This trait represents a channel that a priori does have sending capability,
+ * i.e. ! is not guaranteed to fail (e.g. NullChannel would be a
+ * counter-example).
+ */
+trait AvailableChannel[T] { self: Channel[T] ⇒
+  def safe_!(msg: T)(implicit channel: UntypedChannel = NullChannel): Boolean = {
+    if (isUsable) {
+      try {
+        this ! msg
+        true
+      } catch {
+        case _ ⇒ false
+      }
+    } else false
+  }
+}
+
+/**
+ * All channels used in conjunction with MessageInvocation are untyped by
+ * design, so make this explicit.
+ */
+trait UntypedChannel extends Channel[Any]
+
+object UntypedChannel {
+  implicit def senderOption2Channel(sender: Option[ActorRef]): UntypedChannel =
+    sender match {
+      case Some(actor) ⇒ actor
+      case None        ⇒ NullChannel
+    }
+}
+
+/**
+ * Default channel when none available.
+ */
+case object NullChannel extends UntypedChannel {
+  def !(msg: Any)(implicit channel: UntypedChannel = NullChannel) {
+    throw new IllegalActorStateException("""
+   No sender in scope, can't reply.
+   You have probably:
+      1. Sent a message to an Actor from an instance that is NOT an Actor.
+      2. Invoked a method on an TypedActor from an instance NOT an TypedActor.
+   You may want to have a look at safe_! for a variant returning a Boolean""")
+  }
+  def safe_!(msg: Any)(implicit channel: UntypedChannel = NullChannel): Boolean = false
+  def sendException(ex: Throwable) {}
+  def isUsableOnlyOnce = false
+  def isUsable = false
+  def isReplyable = false
+  def canSendException = false
+}
+
+/**
+ * A channel which may be forwarded: a message received with such a reply
+ * channel attached can be passed on transparently such that a reply from a
+ * later processing stage is sent directly back to the origin. Keep in mind
+ * that not all channels can be used multiple times.
+ */
+trait ForwardableChannel extends UntypedChannel with AvailableChannel[Any] {
+  /**
+   * Get channel by which this channel would reply (ActorRef.forward takes an
+   * implicit ForwardableChannel and uses its .channel as message origin)
+   */
+  def channel: UntypedChannel
+}
+
+object ForwardableChannel {
+  implicit def someS2FC(sender: Some[ActorRef]): ForwardableChannel = sender.get
+  implicit def someIS2FC(implicit sender: Some[ActorRef]): ForwardableChannel = sender.get
+}
+

akka-actor/src/main/scala/akka/actor/FSM.scala

@@ -494,10 +494,7 @@ trait FSM[S, D] extends ListenerManagement {
      * @return this state transition descriptor
      */
     def replying(replyValue: Any): State = {
-      self.sender match {
-        case Some(sender) ⇒ sender ! replyValue
-        case None         ⇒
-      }
+      self.channel safe_! replyValue
       this
     }
 

akka-actor/src/main/scala/akka/actor/TypedActor.scala

@@ -6,7 +6,7 @@ package akka.actor
 
 import akka.japi.{ Creator, Option ⇒ JOption }
 import akka.actor.Actor.{ actorOf, futureToAnyOptionAsTypedOption }
-import akka.dispatch.{ MessageDispatcher, Dispatchers, Future }
+import akka.dispatch.{ MessageDispatcher, Dispatchers, Future, FutureTimeoutException }
 import java.lang.reflect.{ InvocationTargetException, Method, InvocationHandler, Proxy }
 import akka.util.{ Duration }
 import java.util.concurrent.atomic.{ AtomicReference ⇒ AtomVar }
@@ -41,6 +41,7 @@ object TypedActor {
       case "equals"   ⇒ (args.length == 1 && (proxy eq args(0)) || actor == getActorRefFor(args(0))).asInstanceOf[AnyRef] //Force boxing of the boolean
       case "hashCode" ⇒ actor.hashCode.asInstanceOf[AnyRef]
       case _ ⇒
+        implicit val timeout = Actor.Timeout(actor.timeout)
         MethodCall(method, args) match {
           case m if m.isOneWay ⇒
             actor ! m
@@ -48,9 +49,12 @@ object TypedActor {
           case m if m.returnsFuture_? ⇒
             actor !!! m
           case m if m.returnsJOption_? || m.returnsOption_? ⇒
-            (actor !!! m).as[AnyRef] match {
-              case Some(null) | None ⇒ if (m.returnsJOption_?) JOption.none[Any] else None
-              case Some(joption)     ⇒ joption
+            val f = actor ? m
+            try { f.await } catch { case _: FutureTimeoutException ⇒ }
+            f.value match {
+              case None | Some(Right(null))     ⇒ if (m.returnsJOption_?) JOption.none[Any] else None
+              case Some(Right(joption: AnyRef)) ⇒ joption
+              case Some(Left(ex))               ⇒ throw ex
             }
           case m ⇒
             (actor !!! m).get

akka-actor/src/main/scala/akka/dispatch/BalancingDispatcher.scala

@@ -129,10 +129,7 @@ class BalancingDispatcher(
    */
   protected def donate(organ: MessageInvocation, recipient: ActorRef): Boolean = {
     if (organ ne null) {
-      if (organ.senderFuture.isDefined) recipient.postMessageToMailboxAndCreateFutureResultWithTimeout[Any](
-        organ.message, recipient.timeout, organ.sender, organ.senderFuture)
-      else if (organ.sender.isDefined) recipient.postMessageToMailbox(organ.message, organ.sender)
-      else recipient.postMessageToMailbox(organ.message, None)
+      recipient.postMessageToMailbox(organ.message, organ.channel)
       true
     } else false
   }

akka-actor/src/main/scala/akka/dispatch/Dispatcher.scala

@@ -164,10 +164,7 @@ class Dispatcher(
       var invocation = m.dequeue
       lazy val exception = new ActorKilledException("Actor has been stopped")
       while (invocation ne null) {
-        val f = invocation.senderFuture
-        if (f.isDefined)
-          f.get.completeWithException(exception)
-
+        invocation.channel.sendException(exception)
         invocation = m.dequeue
       }
     }

akka-actor/src/main/scala/akka/dispatch/Future.scala

@@ -6,8 +6,8 @@ package akka.dispatch
 
 import akka.AkkaException
 import akka.event.EventHandler
-import akka.actor.{ Actor, Channel }
-import akka.util.Duration
+import akka.actor.{ Actor, Channel, ForwardableChannel, NullChannel, UntypedChannel, ActorRef }
+import akka.util.{ Duration, BoxedType }
 import akka.japi.{ Procedure, Function ⇒ JFunc }
 
 import scala.util.continuations._
@@ -308,6 +308,22 @@ sealed trait Future[+T] {
    */
   def await(atMost: Duration): Future[T]
 
+  /**
+   * Await completion of this Future (as `await`) and return its value if it
+   * conforms to A's erased type.
+   */
+  def as[A](implicit m: Manifest[A]): Option[A] =
+    try {
+      await
+      value match {
+        case None                ⇒ None
+        case Some(_: Left[_, _]) ⇒ None
+        case Some(Right(v))      ⇒ Some(BoxedType(m.erasure).cast(v).asInstanceOf[A])
+      }
+    } catch {
+      case _: Exception ⇒ None
+    }
+
   /**
    * Tests whether this Future has been completed.
    */
@@ -357,7 +373,7 @@ sealed trait Future[+T] {
    * Future. If the Future has already been completed, this will apply
    * immediately.
    */
-  def onComplete(func: Future[T] ⇒ Unit): Future[T]
+  def onComplete(func: Future[T] ⇒ Unit): this.type
 
   /**
    * When the future is completed with a valid result, apply the provided
@@ -369,7 +385,7 @@ sealed trait Future[+T] {
    *   }
    * </pre>
    */
-  final def onResult(pf: PartialFunction[Any, Unit]): Future[T] = onComplete { f ⇒
+  final def onResult(pf: PartialFunction[Any, Unit]): this.type = onComplete { f ⇒
     val optr = f.result
     if (optr.isDefined) {
       val r = optr.get
@@ -496,6 +512,26 @@ sealed trait Future[+T] {
     fa
   }
 
+  /**
+   * Creates a new Future[A] which is completed with this Future's result if
+   * that conforms to A's erased type or a ClassCastException otherwise.
+   */
+  final def mapTo[A](implicit m: Manifest[A]): Future[A] = {
+    val fa = new DefaultPromise[A](timeoutInNanos, NANOS)
+    onComplete { ft ⇒
+      fa complete (ft.value.get match {
+        case l: Left[_, _] ⇒ l.asInstanceOf[Either[Throwable, A]]
+        case Right(t) ⇒
+          try {
+            Right(BoxedType(m.erasure).cast(t).asInstanceOf[A])
+          } catch {
+            case e: ClassCastException ⇒ Left(e)
+          }
+      })
+    }
+    fa
+  }
+
   /**
    * Creates a new Future by applying a function to the successful result of
    * this Future, and returns the result of the function as the new Future.
@@ -586,7 +622,7 @@ sealed trait Future[+T] {
   }
 
   /* Java API */
-  final def onComplete[A >: T](proc: Procedure[Future[A]]): Future[T] = onComplete(proc(_))
+  final def onComplete[A >: T](proc: Procedure[Future[A]]): this.type = onComplete(proc(_))
 
   final def map[A >: T, B](f: JFunc[A, B]): Future[B] = map(f(_))
 
@@ -607,10 +643,7 @@ object Promise {
   /**
    * Construct a completable channel
    */
-  def channel(timeout: Long = Actor.TIMEOUT) = new Channel[Any] {
-    val promise = Promise[Any](timeout)
-    def !(msg: Any) = promise completeWithResult msg
-  }
+  def channel(timeout: Long = Actor.TIMEOUT): ActorPromise = new ActorPromise(timeout)
 
   private[akka] val callbacksPendingExecution = new ThreadLocal[Option[Stack[() ⇒ Unit]]]() {
     override def initialValue = None
@@ -625,26 +658,26 @@ trait Promise[T] extends Future[T] {
    * Completes this Future with the specified result, if not already completed.
    * @return this
    */
-  def complete(value: Either[Throwable, T]): Future[T]
+  def complete(value: Either[Throwable, T]): this.type
 
   /**
    * Completes this Future with the specified result, if not already completed.
    * @return this
    */
-  final def completeWithResult(result: T): Future[T] = complete(Right(result))
+  final def completeWithResult(result: T): this.type = complete(Right(result))
 
   /**
    * Completes this Future with the specified exception, if not already completed.
    * @return this
    */
-  final def completeWithException(exception: Throwable): Future[T] = complete(Left(exception))
+  final def completeWithException(exception: Throwable): this.type = complete(Left(exception))
 
   /**
    * Completes this Future with the specified other Future, when that Future is completed,
    * unless this Future has already been completed.
    * @return this.
    */
-  final def completeWith(other: Future[T]): Future[T] = {
+  final def completeWith(other: Future[T]): this.type = {
     other onComplete { f ⇒ complete(f.value.get) }
     this
   }
@@ -725,7 +758,7 @@ class DefaultPromise[T](timeout: Long, timeunit: TimeUnit) extends Promise[T] {
     }
   }
 
-  def complete(value: Either[Throwable, T]): DefaultPromise[T] = {
+  def complete(value: Either[Throwable, T]): this.type = {
     _lock.lock
     val notifyTheseListeners = try {
       if (_value.isEmpty) { //Only complete if we aren't expired
@@ -772,7 +805,7 @@ class DefaultPromise[T](timeout: Long, timeunit: TimeUnit) extends Promise[T] {
     this
   }
 
-  def onComplete(func: Future[T] ⇒ Unit): Promise[T] = {
+  def onComplete(func: Future[T] ⇒ Unit): this.type = {
     _lock.lock
     val notifyNow = try {
       if (_value.isEmpty) {
@@ -804,6 +837,36 @@ class DefaultPromise[T](timeout: Long, timeunit: TimeUnit) extends Promise[T] {
   private def timeLeft(): Long = timeoutInNanos - (currentTimeInNanos - _startTimeInNanos)
 }
 
+class ActorPromise(timeout: Long, timeunit: TimeUnit)
+  extends DefaultPromise[Any](timeout, timeunit)
+  with ForwardableChannel {
+  def this() = this(0, MILLIS)
+  def this(timeout: Long) = this(timeout, MILLIS)
+
+  def !(message: Any)(implicit channel: UntypedChannel = NullChannel) = completeWithResult(message)
+
+  def sendException(ex: Throwable) = completeWithException(ex)
+
+  def channel: UntypedChannel = this
+
+  def isUsableOnlyOnce = true
+  def isUsable = !isCompleted
+  def isReplyable = false
+  def canSendException = true
+
+  @deprecated("ActorPromise merged with Channel[Any], just use 'this'", "1.2")
+  def future = this
+}
+
+object ActorPromise {
+  def apply(f: Promise[Any]): ActorPromise =
+    new ActorPromise(f.timeoutInNanos, NANOS) {
+      completeWith(f)
+      override def !(message: Any)(implicit channel: UntypedChannel) = f completeWithResult message
+      override def sendException(ex: Throwable) = f completeWithException ex
+    }
+}
+
 /**
  * An already completed Future is seeded with it's result at creation, is useful for when you are participating in
  * a Future-composition but you already have a value to contribute.
@@ -811,10 +874,10 @@ class DefaultPromise[T](timeout: Long, timeunit: TimeUnit) extends Promise[T] {
 sealed class KeptPromise[T](suppliedValue: Either[Throwable, T]) extends Promise[T] {
   val value = Some(suppliedValue)
 
-  def complete(value: Either[Throwable, T]): Promise[T] = this
-  def onComplete(func: Future[T] ⇒ Unit): Future[T] = { func(this); this }
-  def await(atMost: Duration): Future[T] = this
-  def await: Future[T] = this
+  def complete(value: Either[Throwable, T]): this.type = this
+  def onComplete(func: Future[T] ⇒ Unit): this.type = { func(this); this }
+  def await(atMost: Duration): this.type = this
+  def await: this.type = this
   def isExpired: Boolean = true
   def timeoutInNanos: Long = 0
 }

akka-actor/src/main/scala/akka/dispatch/MessageHandling.scala

@@ -16,10 +16,9 @@ import akka.actor._
 /**
  * @author <a href="http://jonasboner.com">Jonas Bon&#233;r</a>
  */
-final case class MessageInvocation(receiver: ActorRef,
-                                   message: Any,
-                                   sender: Option[ActorRef],
-                                   senderFuture: Option[Promise[Any]]) {
+final case class MessageInvocation(val receiver: ActorRef,
+                                   val message: Any,
+                                   val channel: UntypedChannel) {
   if (receiver eq null) throw new IllegalArgumentException("Receiver can't be null")
 
   final def invoke() {

akka-actor/src/main/scala/akka/routing/Pool.scala

@@ -5,6 +5,7 @@
 package akka.routing
 
 import akka.actor.{ Actor, ActorRef, PoisonPill }
+import akka.dispatch.{ Promise }
 
 /**
  * Actor pooling
@@ -195,7 +196,7 @@ trait MailboxPressureCapacitor {
  */
 trait ActiveFuturesPressureCapacitor {
   def pressure(delegates: Seq[ActorRef]): Int =
-    delegates count { _.senderFuture.isDefined }
+    delegates count { _.channel.isInstanceOf[Promise[Any]] }
 }
 
 /**

akka-actor/src/main/scala/akka/util/BoxedType.scala

@@ -0,0 +1,25 @@
+/**
+ * Copyright (C) 2009-2011 Scalable Solutions AB <http://scalablesolutions.se>
+ */
+package akka.util
+
+import java.{ lang ⇒ jl }
+
+object BoxedType {
+
+  private val toBoxed = Map[Class[_], Class[_]](
+    classOf[Boolean] -> classOf[jl.Boolean],
+    classOf[Byte] -> classOf[jl.Byte],
+    classOf[Char] -> classOf[jl.Character],
+    classOf[Short] -> classOf[jl.Short],
+    classOf[Int] -> classOf[jl.Integer],
+    classOf[Long] -> classOf[jl.Long],
+    classOf[Float] -> classOf[jl.Float],
+    classOf[Double] -> classOf[jl.Double],
+    classOf[Unit] -> classOf[scala.runtime.BoxedUnit])
+
+  def apply(c: Class[_]): Class[_] = {
+    if (c.isPrimitive) toBoxed(c) else c
+  }
+
+}

akka-camel/src/main/scala/akka/camel/Producer.scala

@@ -10,6 +10,7 @@ import org.apache.camel._
 import org.apache.camel.processor.SendProcessor
 
 import akka.actor.{ Actor, ActorRef, UntypedActor }
+import akka.dispatch.ActorPromise
 
 /**
  * Support trait for producing messages to Camel endpoints.
@@ -96,10 +97,9 @@ trait ProducerSupport { this: Actor ⇒
     val exchange = createExchange(pattern).fromRequestMessage(cmsg)
     processor.process(exchange, new AsyncCallback {
       val producer = self
-      // Need copies of sender and senderFuture references here
-      // since the callback could be done later by another thread.
-      val sender = self.sender
-      val senderFuture = self.senderFuture
+      // Need copies of channel reference here since the callback could be done
+      // later by another thread.
+      val channel = self.channel
 
       def done(doneSync: Boolean): Unit = {
         (doneSync, exchange.isFailed) match {
@@ -114,10 +114,12 @@ trait ProducerSupport { this: Actor ⇒
         receiveAfterProduce(result)
 
       private def dispatchAsync(result: Any) = {
-        if (senderFuture.isDefined)
-          producer.postMessageToMailboxAndCreateFutureResultWithTimeout(result, producer.timeout, sender, senderFuture)
-        else
-          producer.postMessageToMailbox(result, sender)
+        channel match {
+          case _: ActorPromise ⇒
+            producer.postMessageToMailboxAndCreateFutureResultWithTimeout(result, producer.timeout, channel)
+          case _ ⇒
+            producer.postMessageToMailbox(result, channel)
+        }
       }
     })
   }

akka-camel/src/main/scala/akka/camel/component/ActorComponent.scala

@@ -285,7 +285,7 @@ private[akka] class AsyncCallbackAdapter(exchange: Exchange, callback: AsyncCall
    * @param message reply message
    * @param sender ignored
    */
-  protected[akka] def postMessageToMailbox(message: Any, senderOption: Option[ActorRef]) = {
+  protected[akka] def postMessageToMailbox(message: Any, channel: UntypedChannel) = {
     message match {
       case Ack          ⇒ { /* no response message to set */ }
       case msg: Failure ⇒ exchange.fromFailureMessage(msg)
@@ -312,7 +312,7 @@ private[akka] class AsyncCallbackAdapter(exchange: Exchange, callback: AsyncCall
   def shutdownLinkedActors: Unit = unsupported
   def supervisor: Option[ActorRef] = unsupported
   def homeAddress: Option[InetSocketAddress] = None
-  protected[akka] def postMessageToMailboxAndCreateFutureResultWithTimeout[T](message: Any, timeout: Long, senderOption: Option[ActorRef], senderFuture: Option[Promise[T]]) = unsupported
+  protected[akka] def postMessageToMailboxAndCreateFutureResultWithTimeout(message: Any, timeout: Long, channel: UntypedChannel) = unsupported
   protected[akka] def mailbox: AnyRef = unsupported
   protected[akka] def mailbox_=(msg: AnyRef): AnyRef = unsupported
   protected[akka] def restart(reason: Throwable, maxNrOfRetries: Option[Int], withinTimeRange: Option[Int]): Unit = unsupported

akka-cluster/src/main/scala/akka/cluster/ClusterActorRef.scala

@@ -8,7 +8,7 @@ import Cluster._
 import akka.actor._
 import akka.actor.Actor._
 import akka.event.EventHandler
-import akka.dispatch.Promise
+import akka.dispatch.Future
 
 import java.net.InetSocketAddress
 import java.util.concurrent.atomic.AtomicReference
@@ -37,15 +37,23 @@ class ClusterActorRef private[akka] (
 
   def connections: Map[InetSocketAddress, ActorRef] = inetSocketAddressToActorRefMap.get
 
-  override def postMessageToMailbox(message: Any, senderOption: Option[ActorRef]): Unit =
-    route(message)(senderOption)
+  override def postMessageToMailbox(message: Any, channel: UntypedChannel): Unit = {
+    val sender = channel match {
+      case ref: ActorRef ⇒ Some(ref)
+      case _             ⇒ None
+    }
+    route(message)(sender)
+  }
 
-  override def postMessageToMailboxAndCreateFutureResultWithTimeout[T](
+  override def postMessageToMailboxAndCreateFutureResultWithTimeout(
     message: Any,
     timeout: Long,
-    senderOption: Option[ActorRef],
-    senderFuture: Option[Promise[T]]): Promise[T] = {
-    route[T](message, timeout)(senderOption).asInstanceOf[Promise[T]]
+    channel: UntypedChannel): Future[Any] = {
+    val sender = channel match {
+      case ref: ActorRef ⇒ Some(ref)
+      case _             ⇒ None
+    }
+    route[Any](message, timeout)(sender)
   }
 
   private[akka] def failOver(fromInetSocketAddress: InetSocketAddress, toInetSocketAddress: InetSocketAddress) {

akka-cluster/src/main/scala/akka/cluster/ReplicatedClusterRef.scala

@@ -79,14 +79,13 @@ class ReplicatedActorRef private[akka] (actorRef: ActorRef, val address: String)
   def startLink(actorRef: ActorRef): ActorRef = actorRef.startLink(actorRef)
   def supervisor: Option[ActorRef] = actorRef.supervisor
   def linkedActors: JMap[Uuid, ActorRef] = actorRef.linkedActors
-  protected[akka] def postMessageToMailbox(message: Any, senderOption: Option[ActorRef]) {
-    actorRef.postMessageToMailbox(message, senderOption)
+  protected[akka] def postMessageToMailbox(message: Any, channel: UntypedChannel) {
+    actorRef.postMessageToMailbox(message, channel)
   }
-  protected[akka] def postMessageToMailboxAndCreateFutureResultWithTimeout[T](
+  protected[akka] def postMessageToMailboxAndCreateFutureResultWithTimeout(
     message: Any,
     timeout: Long,
-    senderOption: Option[ActorRef],
-    senderFuture: Option[Promise[T]]): Promise[T] = actorRef.postMessageToMailboxAndCreateFutureResultWithTimeout(message, timeout, senderOption, senderFuture)
+    channel: UntypedChannel): Future[Any] = actorRef.postMessageToMailboxAndCreateFutureResultWithTimeout(message, timeout, channel)
   protected[akka] def actorInstance: AtomicReference[Actor] = actorRef.actorInstance
   protected[akka] def supervisor_=(sup: Option[ActorRef]) {
     actorRef.supervisor_=(sup)

akka-durable-mailboxes/akka-mailboxes-common/src/main/scala/akka/actor/mailbox/DurableDispatcher.scala

@@ -94,7 +94,7 @@ case class DurableDispatcher(
   override def createMailbox(actorRef: ActorRef): AnyRef = _storage.createFor(actorRef)
 
   private[akka] override def dispatch(invocation: MessageInvocation): Unit = {
-    if (invocation.senderFuture.isDefined)
+    if (invocation.channel.isInstanceOf[ActorPromise])
       throw new IllegalArgumentException("Durable mailboxes do not support Future-based messages from !! and !!!")
     super.dispatch(invocation)
   }
@@ -131,7 +131,7 @@ case class DurablePinnedDispatcher(
   override def createMailbox(actorRef: ActorRef): AnyRef = _storage.createFor(actorRef)
 
   private[akka] override def dispatch(invocation: MessageInvocation): Unit = {
-    if (invocation.senderFuture.isDefined)
+    if (invocation.channel.isInstanceOf[ActorPromise])
       throw new IllegalArgumentException("Actor has a durable mailbox that does not support !! or !!!")
     super.dispatch(invocation)
   }

akka-durable-mailboxes/akka-mailboxes-common/src/main/scala/akka/actor/mailbox/DurableMailbox.scala

@@ -5,7 +5,7 @@ package akka.actor.mailbox
 
 import MailboxProtocol._
 
-import akka.actor.{Actor, ActorRef}
+import akka.actor.{Actor, ActorRef, NullChannel}
 import akka.dispatch._
 import akka.event.EventHandler
 import akka.remote.MessageSerializer
@@ -48,7 +48,10 @@ abstract class DurableExecutableMailbox(owner: ActorRef) extends MessageQueue wi
     val builder = DurableMailboxMessageProtocol.newBuilder
       .setOwnerAddress(ownerAddress)
       .setMessage(message.toByteString)
-    if (durableMessage.sender.isDefined) builder.setSenderAddress(durableMessage.sender.get.address)
+    durableMessage.channel match {
+      case a : ActorRef => builder.setSenderAddress(a.address)
+      case _ =>
+    }
     builder.build.toByteArray
   }
 
@@ -62,10 +65,14 @@ abstract class DurableExecutableMailbox(owner: ActorRef) extends MessageQueue wi
       throw new DurableMailboxException("No actor could be found for address [" + ownerAddress + "], could not deserialize message."))
 
 
-    val sender = if (durableMessage.hasSenderAddress) {
+    val senderOption = if (durableMessage.hasSenderAddress) {
       Actor.registry.actorFor(durableMessage.getSenderAddress)
     } else None
+    val sender = senderOption match {
+      case Some(ref) => ref
+      case None => NullChannel
+    }
 
-    new MessageInvocation(owner, message, sender, None)
+    new MessageInvocation(owner, message, sender)
   }
 }

akka-remote/src/main/scala/akka/remote/netty/NettyRemoteSupport.scala

@@ -4,7 +4,7 @@
 
 package akka.remote.netty
 
-import akka.dispatch.{ DefaultPromise, Promise, Future }
+import akka.dispatch.{ ActorPromise, DefaultPromise, Promise, Future }
 import akka.remote.{ MessageSerializer, RemoteClientSettings, RemoteServerSettings }
 import akka.remote.protocol.RemoteProtocol._
 import akka.serialization.RemoteActorSerialization
@@ -913,8 +913,7 @@ class RemoteServerHandler(
         else actorRef.postMessageToMailboxAndCreateFutureResultWithTimeout(
           message,
           request.getActorInfo.getTimeout,
-          None,
-          Some(new DefaultPromise[Any](request.getActorInfo.getTimeout).
+          new ActorPromise(request.getActorInfo.getTimeout).
             onComplete(_.value.get match {
               case l: Left[Throwable, Any] ⇒ write(channel, createErrorReplyMessage(l.a, request))
               case r: Right[Throwable, Any] ⇒
@@ -931,7 +930,7 @@ class RemoteServerHandler(
                 if (request.hasSupervisorUuid) messageBuilder.setSupervisorUuid(request.getSupervisorUuid)
 
                 write(channel, RemoteEncoder.encode(messageBuilder.build))
-            })))
+            }))
     }
   }
 

akka-testkit/src/main/scala/akka/testkit/CallingThreadDispatcher.scala

@@ -5,7 +5,7 @@ package akka.testkit
 
 import akka.event.EventHandler
 import akka.actor.ActorRef
-import akka.dispatch.{ MessageDispatcher, MessageInvocation, FutureInvocation }
+import akka.dispatch.{ MessageDispatcher, MessageInvocation, FutureInvocation, Promise, ActorPromise }
 import java.util.concurrent.locks.ReentrantLock
 import java.util.LinkedList
 import java.util.concurrent.RejectedExecutionException
@@ -140,14 +140,14 @@ class CallingThreadDispatcher(val warnings: Boolean = true) extends MessageDispa
     val queue = mbox.queue
     val execute = mbox.suspended.ifElseYield {
       queue.push(handle)
-      if (warnings && handle.senderFuture.isDefined) {
+      if (warnings && handle.channel.isInstanceOf[Promise[_]]) {
         EventHandler.warning(this, "suspended, creating Future could deadlock; target: %s" format handle.receiver)
       }
       false
     } {
       queue.push(handle)
       if (queue.isActive) {
-        if (warnings && handle.senderFuture.isDefined) {
+        if (warnings && handle.channel.isInstanceOf[Promise[_]]) {
           EventHandler.warning(this, "blocked on this thread, creating Future could deadlock; target: %s" format handle.receiver)
         }
         false
@@ -186,14 +186,18 @@ class CallingThreadDispatcher(val warnings: Boolean = true) extends MessageDispa
       if (handle ne null) {
         try {
           handle.invoke
-          val f = handle.senderFuture
-          if (warnings && f.isDefined && !f.get.isCompleted) {
+          if (warnings) handle.channel match {
+            case f: ActorPromise if !f.isCompleted ⇒
               EventHandler.warning(this, "calling %s with message %s did not reply as expected, might deadlock" format (handle.receiver, handle.message))
-          }
-        } catch {
-          case _ ⇒ queue.leave
+            case _ ⇒
           }
           true
+        } catch {
+          case e ⇒
+            EventHandler.error(this, e)
+            queue.leave
+            false
+        }
       } else if (queue.isActive) {
         queue.leave
         false

akka-testkit/src/main/scala/akka/testkit/TestKit.scala

@@ -3,7 +3,7 @@
  */
 package akka.testkit
 
-import akka.actor.{ Actor, FSM }
+import akka.actor._
 import Actor._
 import akka.util.Duration
 import akka.util.duration._
@@ -17,9 +17,19 @@ object TestActor {
 
   case class SetTimeout(d: Duration)
   case class SetIgnore(i: Ignore)
+
+  trait Message {
+    def msg: AnyRef
+    def channel: UntypedChannel
+  }
+  case class RealMessage(msg: AnyRef, channel: UntypedChannel) extends Message
+  case object NullMessage extends Message {
+    override def msg: AnyRef = throw new IllegalActorStateException("last receive did not dequeue a message")
+    override def channel: UntypedChannel = throw new IllegalActorStateException("last receive did not dequeue a message")
+  }
 }
 
-class TestActor(queue: BlockingDeque[AnyRef]) extends Actor with FSM[Int, TestActor.Ignore] {
+class TestActor(queue: BlockingDeque[TestActor.Message]) extends Actor with FSM[Int, TestActor.Ignore] {
   import FSM._
   import TestActor._
 
@@ -36,7 +46,7 @@ class TestActor(queue: BlockingDeque[AnyRef]) extends Actor with FSM[Int, TestAc
     case Event(x: AnyRef, ign) ⇒
       val ignore = ign map (z ⇒ if (z isDefinedAt x) z(x) else false) getOrElse false
       if (!ignore) {
-        queue.offerLast(x)
+        queue.offerLast(RealMessage(x, self.channel))
       }
       stay
   }
@@ -76,19 +86,23 @@ class TestActor(queue: BlockingDeque[AnyRef]) extends Actor with FSM[Int, TestAc
  */
 trait TestKit {
 
-  private val queue = new LinkedBlockingDeque[AnyRef]()
+  import TestActor.{ Message, RealMessage, NullMessage }
+
+  private val queue = new LinkedBlockingDeque[Message]()
+  private[akka] var lastMessage: Message = NullMessage
 
   /**
    * ActorRef of the test actor. Access is provided to enable e.g.
    * registration as message target.
    */
-  protected val testActor = actorOf(new TestActor(queue)).start()
+  implicit val testActor = actorOf(new TestActor(queue)).start()
 
   /**
    * Implicit sender reference so that replies are possible for messages sent
    * from the test class.
    */
-  protected implicit val senderOption = Some(testActor)
+  @deprecated("will be removed after 1.2, replaced by implicit testActor", "1.2")
+  val senderOption = Some(testActor)
 
   private var end: Duration = Duration.Inf
   /*
@@ -183,6 +197,14 @@ trait TestKit {
    */
   def within[T](max: Duration)(f: ⇒ T): T = within(0 seconds, max)(f)
 
+  /**
+   * Send reply to the last dequeued message. Will throw
+   * IllegalActorStateException if no message has been dequeued, yet. Dequeuing
+   * means reception of the message as part of an expect... or receive... call,
+   * not reception by the testActor.
+   */
+  def reply(msg: AnyRef) { lastMessage.channel ! msg }
+
   /**
    * Same as `expectMsg`, but takes the maximum wait time from the innermost
    * enclosing `within` block.
@@ -396,16 +418,21 @@ trait TestKit {
    */
   def receiveWhile[T](max: Duration)(f: PartialFunction[AnyRef, T]): Seq[T] = {
     val stop = now + max
+    var msg: Message = NullMessage
 
     @tailrec
     def doit(acc: List[T]): List[T] = {
-      receiveOne(stop - now) match {
-        case null ⇒
+      receiveOne(stop - now)
+      lastMessage match {
+        case NullMessage ⇒
+          lastMessage = msg
           acc.reverse
-        case o if (f isDefinedAt o) ⇒
+        case RealMessage(o, _) if (f isDefinedAt o) ⇒
+          msg = lastMessage
           doit(f(o) :: acc)
-        case o ⇒
-          queue.offerFirst(o)
+        case RealMessage(o, _) ⇒
+          queue.offerFirst(lastMessage)
+          lastMessage = msg
           acc.reverse
       }
     }
@@ -415,7 +442,10 @@ trait TestKit {
     ret
   }
 
-  private def receiveN(n: Int, stop: Duration): Seq[AnyRef] = {
+  /**
+   * Receive N messages in a row before the given deadline.
+   */
+  def receiveN(n: Int, stop: Duration): Seq[AnyRef] = {
     for { x ← 1 to n } yield {
       val timeout = stop - now
       val o = receiveOne(timeout)
@@ -424,7 +454,12 @@ trait TestKit {
     }
   }
 
-  private def receiveOne(max: Duration): AnyRef = {
+  /**
+   * Receive one message from the internal queue of the TestActor. If the given
+   * duration is zero, the queue is polled (non-blocking).
+   */
+  def receiveOne(max: Duration): AnyRef = {
+    val message =
       if (max == 0.seconds) {
         queue.pollFirst
       } else if (max.finite_?) {
@@ -432,9 +467,52 @@ trait TestKit {
       } else {
         queue.takeFirst
       }
+    message match {
+      case null ⇒
+        lastMessage = NullMessage
+        null
+      case RealMessage(msg, _) ⇒
+        lastMessage = message
+        msg
+    }
   }
 
   private def format(u: TimeUnit, d: Duration) = "%.3f %s".format(d.toUnit(u), u.toString.toLowerCase)
 }
 
-// vim: set ts=2 sw=2 et:
+/**
+ * TestKit-based probe which allows sending, reception and reply.
+ */
+class TestProbe extends TestKit {
+
+  /**
+   * Shorthand to get the testActor.
+   */
+  def ref = testActor
+
+  /**
+   * Send message to an actor while using the probe's TestActor as the sender.
+   * Replies will be available for inspection with all of TestKit's assertion
+   * methods.
+   */
+  def send(actor: ActorRef, msg: AnyRef) = {
+    actor ! msg
+  }
+
+  /**
+   * Forward this message as if in the TestActor's receive method with self.forward.
+   */
+  def forward(actor: ActorRef, msg: AnyRef = lastMessage.msg) {
+    actor.!(msg)(lastMessage.channel)
+  }
+
+  /**
+   * Get channel of last received message.
+   */
+  def channel = lastMessage.channel
+
+}
+
+object TestProbe {
+  def apply() = new TestProbe
+}

akka-testkit/src/test/scala/akka/testkit/TestActorRefSpec.scala

@@ -190,7 +190,7 @@ class TestActorRefSpec extends WordSpec with MustMatchers with BeforeAndAfterEac
 
     "support futures" in {
       val a = TestActorRef[WorkerActor].start()
-      val f: Future[String] = a !!! "work"
+      val f = a ? "work" mapTo manifest[String]
       f must be('completed)
       f.get must equal("workDone")
     }
@@ -239,9 +239,8 @@ class TestActorRefSpec extends WordSpec with MustMatchers with BeforeAndAfterEac
       intercept[IllegalActorStateException] { ref("work") }
       val ch = Promise.channel()
       ref ! ch
-      val f = ch.promise
-      f must be('completed)
-      f.get must be("complexReply")
+      ch must be('completed)
+      ch.get must be("complexReply")
     }
 
   }

akka-testkit/src/test/scala/akka/testkit/TestProbeSpec.scala

@@ -0,0 +1,45 @@
+package akka.testkit
+
+import org.scalatest.WordSpec
+import org.scalatest.matchers.MustMatchers
+import org.scalatest.{ BeforeAndAfterEach, WordSpec }
+import akka.actor._
+import akka.config.Supervision.OneForOneStrategy
+import akka.event.EventHandler
+import akka.dispatch.Future
+import akka.util.duration._
+
+class TestProbeSpec extends WordSpec with MustMatchers {
+
+  "A TestProbe" must {
+
+    "reply to futures" in {
+      val tk = TestProbe()
+      val future = tk.ref ? "hello"
+      tk.expectMsg(0 millis, "hello") // TestActor runs on CallingThreadDispatcher
+      tk.reply("world")
+      future must be('completed)
+      future.get must equal("world")
+    }
+
+    "reply to messages" in {
+      val tk1 = TestProbe()
+      val tk2 = TestProbe()
+      tk1.ref.!("hello")(tk2.ref)
+      tk1.expectMsg(0 millis, "hello")
+      tk1.reply("world")
+      tk2.expectMsg(0 millis, "world")
+    }
+
+    "properly send and reply to messages" in {
+      val probe1 = TestProbe()
+      val probe2 = TestProbe()
+      probe1.send(probe2.ref, "hello")
+      probe2.expectMsg(0 millis, "hello")
+      probe2.reply("world")
+      probe1.expectMsg(0 millis, "world")
+    }
+
+  }
+
+}

akka-tutorials/akka-tutorial-second/src/main/java/akka/tutorial/java/second/Pi.java

@@ -184,10 +184,10 @@ public class Pi {
 
     // send calculate message
     long timeout = 60000;
-    Future<Double> replyFuture = master.sendRequestReplyFuture(new Calculate(), timeout, null);
-    Option<Double> result = replyFuture.await().resultOrException();
+    Future<Object> replyFuture = master.sendRequestReplyFuture(new Calculate(), timeout, null);
+    Option<Object> result = replyFuture.await().resultOrException();
     if (result.isDefined()) {
-      double pi = result.get();
+      double pi = (Double) result.get();
       // TODO java api for EventHandler?
 //      EventHandler.info(this, String.format("\n\tPi estimate: \t\t%s\n\tCalculation time: \t%s millis", pi, (currentTimeMillis() - start)));
       System.out.println(String.format("\n\tPi estimate: \t\t%s\n\tCalculation time: \t%s millis", pi, (currentTimeMillis() - start)));