remove SystemEnvelope

- channel field was always set to NullChannel and not used
- receiver field is better put into the Mailbox, because there it takes
  space only once per actor
- leaves only the bare SystemMessage to be queued

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

@@ -146,8 +146,8 @@ abstract class MailboxSpec extends AkkaSpec with BeforeAndAfterAll with BeforeAn
 class DefaultMailboxSpec extends MailboxSpec {
   lazy val name = "The default mailbox implementation"
   def factory = {
-    case u: UnboundedMailbox ⇒ u.create(null)
+    case u: UnboundedMailbox ⇒ u.create(null, null)
-    case b: BoundedMailbox   ⇒ b.create(null)
+    case b: BoundedMailbox   ⇒ b.create(null, null)
   }
 }
 
@@ -155,7 +155,7 @@ class PriorityMailboxSpec extends MailboxSpec {
   val comparator = PriorityGenerator(_.##)
   lazy val name = "The priority mailbox implementation"
   def factory = {
-    case UnboundedMailbox()                    ⇒ UnboundedPriorityMailbox(comparator).create(null)
+    case UnboundedMailbox()                    ⇒ UnboundedPriorityMailbox(comparator).create(null, null)
-    case BoundedMailbox(capacity, pushTimeOut) ⇒ BoundedPriorityMailbox(comparator, capacity, pushTimeOut).create(null)
+    case BoundedMailbox(capacity, pushTimeOut) ⇒ BoundedPriorityMailbox(comparator, capacity, pushTimeOut).create(null, null)
   }
 }

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

@@ -245,7 +245,7 @@ private[akka] class ActorCell(
     if (props.supervisor.isDefined) {
       props.supervisor.get match {
         case l: LocalActorRef ⇒
-          l.underlying.dispatcher.systemDispatch(SystemEnvelope(l.underlying, akka.dispatch.Supervise(self), NullChannel))
+          l.underlying.dispatcher.systemDispatch(l.underlying, akka.dispatch.Supervise(self))
         case other ⇒ throw new UnsupportedOperationException("Supervision failure: " + other + " cannot be a supervisor, only LocalActorRefs can")
       }
     }
@@ -253,20 +253,20 @@ private[akka] class ActorCell(
     dispatcher.attach(this)
   }
 
-  def suspend(): Unit = dispatcher.systemDispatch(SystemEnvelope(this, Suspend, NullChannel))
+  def suspend(): Unit = dispatcher.systemDispatch(this, Suspend())
 
-  def resume(): Unit = dispatcher.systemDispatch(SystemEnvelope(this, Resume, NullChannel))
+  def resume(): Unit = dispatcher.systemDispatch(this, Resume())
 
   private[akka] def stop(): Unit =
-    dispatcher.systemDispatch(SystemEnvelope(this, Terminate, NullChannel))
+    dispatcher.systemDispatch(this, Terminate())
 
   def startsMonitoring(subject: ActorRef): ActorRef = {
-    dispatcher.systemDispatch(SystemEnvelope(this, Link(subject), NullChannel))
+    dispatcher.systemDispatch(this, Link(subject))
     subject
   }
 
   def stopsMonitoring(subject: ActorRef): ActorRef = {
-    dispatcher.systemDispatch(SystemEnvelope(this, Unlink(subject), NullChannel))
+    dispatcher.systemDispatch(this, Unlink(subject))
     subject
   }
 
@@ -324,7 +324,7 @@ private[akka] class ActorCell(
     }
   }
 
-  def systemInvoke(envelope: SystemEnvelope) {
+  def systemInvoke(message: SystemMessage) {
 
     def create(): Unit = try {
       val created = newActor()
@@ -337,7 +337,6 @@ private[akka] class ActorCell(
         app.eventHandler.error(e, self, "error while creating actor")
         // prevent any further messages to be processed until the actor has been restarted
         dispatcher.suspend(this)
-        envelope.channel.sendException(e)
       } finally {
         if (supervisor.isDefined) supervisor.get ! Failed(self, e) else self.stop()
       }
@@ -369,7 +368,6 @@ private[akka] class ActorCell(
         app.eventHandler.error(e, self, "error while creating actor")
         // prevent any further messages to be processed until the actor has been restarted
         dispatcher.suspend(this)
-        envelope.channel.sendException(e)
       } finally {
         if (supervisor.isDefined) supervisor.get ! Failed(self, e) else self.stop()
       }
@@ -424,24 +422,24 @@ private[akka] class ActorCell(
     try {
       val isClosed = mailbox.isClosed //Fence plus volatile read
       if (!isClosed) {
-        envelope.message match {
+        message match {
-          case Create          ⇒ create()
+          case Create(_)          ⇒ create()
-          case Recreate(cause) ⇒ recreate(cause)
+          case Recreate(cause, _) ⇒ recreate(cause)
-          case Link(subject) ⇒
+          case Link(subject, _) ⇒
             app.deathWatch.subscribe(self, subject)
             if (app.AkkaConfig.DebugLifecycle) app.eventHandler.debug(self, "now monitoring " + subject)
-          case Unlink(subject) ⇒
+          case Unlink(subject, _) ⇒
             app.deathWatch.unsubscribe(self, subject)
             if (app.AkkaConfig.DebugLifecycle) app.eventHandler.debug(self, "stopped monitoring " + subject)
-          case Suspend          ⇒ suspend()
+          case Suspend(_)          ⇒ suspend()
-          case Resume           ⇒ resume()
+          case Resume(_)           ⇒ resume()
-          case Terminate        ⇒ terminate()
+          case Terminate(_)        ⇒ terminate()
-          case Supervise(child) ⇒ supervise(child)
+          case Supervise(child, _) ⇒ supervise(child)
         }
       }
     } catch {
       case e ⇒ //Should we really catch everything here?
-        app.eventHandler.error(e, self, "error while processing " + envelope.message)
+        app.eventHandler.error(e, self, "error while processing " + message)
         //TODO FIXME How should problems here be handled?
         throw e
     }
@@ -495,7 +493,7 @@ private[akka] class ActorCell(
 
   def handleChildTerminated(child: ActorRef): Unit = _children = props.faultHandler.handleChildTerminated(child, _children)
 
-  def restart(cause: Throwable): Unit = dispatcher.systemDispatch(SystemEnvelope(this, Recreate(cause), NullChannel))
+  def restart(cause: Throwable): Unit = dispatcher.systemDispatch(this, Recreate(cause))
 
   def checkReceiveTimeout() {
     cancelReceiveTimeout()

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

@@ -24,25 +24,17 @@ final case class Envelope(val receiver: ActorCell, val message: Any, val channel
   }
 }
 
-sealed trait SystemMessage extends PossiblyHarmful
+sealed trait SystemMessage extends PossiblyHarmful {
-case object Create extends SystemMessage
+  def next: SystemMessage
-case class Recreate(cause: Throwable) extends SystemMessage
-case object Suspend extends SystemMessage
-case object Resume extends SystemMessage
-case object Terminate extends SystemMessage
-case class Supervise(child: ActorRef) extends SystemMessage
-case class Link(subject: ActorRef) extends SystemMessage
-case class Unlink(subject: ActorRef) extends SystemMessage
-
-final case class SystemEnvelope(val receiver: ActorCell, val message: SystemMessage, val channel: UntypedChannel) {
-  if (receiver eq null) throw new IllegalArgumentException("Receiver can't be null")
-  /**
-   * @return whether to proceed with processing other messages
-   */
-  final def invoke() {
-    receiver systemInvoke this
-  }
 }
+case class Create(next: SystemMessage = null) extends SystemMessage
+case class Recreate(cause: Throwable, next: SystemMessage = null) extends SystemMessage
+case class Suspend(next: SystemMessage = null) extends SystemMessage
+case class Resume(next: SystemMessage = null) extends SystemMessage
+case class Terminate(next: SystemMessage = null) extends SystemMessage
+case class Supervise(child: ActorRef, next: SystemMessage = null) extends SystemMessage
+case class Link(subject: ActorRef, next: SystemMessage = null) extends SystemMessage
+case class Unlink(subject: ActorRef, next: SystemMessage = null) extends SystemMessage
 
 final case class TaskInvocation(app: AkkaApplication, function: () ⇒ Unit, cleanup: () ⇒ Unit) extends Runnable {
   def run() {
@@ -87,13 +79,13 @@ abstract class MessageDispatcher(val app: AkkaApplication) extends Serializable
    */
   protected[akka] val deadLetterMailbox: Mailbox = DeadLetterMailbox
 
-  object DeadLetterMailbox extends Mailbox {
+  object DeadLetterMailbox extends Mailbox(null) {
     becomeClosed()
     override def dispatcher = null //MessageDispatcher.this
     override def enqueue(envelope: Envelope) { envelope.channel sendException new ActorKilledException("Actor has been stopped") }
     override def dequeue() = null
-    override def systemEnqueue(handle: SystemEnvelope): Unit = ()
+    override def systemEnqueue(handle: SystemMessage): Unit = ()
-    override def systemDequeue(): SystemEnvelope = null
+    override def systemDequeue(): SystemMessage = null
     override def hasMessages = false
     override def hasSystemMessages = false
     override def numberOfMessages = 0
@@ -174,7 +166,7 @@ abstract class MessageDispatcher(val app: AkkaApplication) extends Serializable
    */
   protected[akka] def register(actor: ActorCell) {
     if (uuids add actor.uuid) {
-      systemDispatch(SystemEnvelope(actor, Create, NullChannel)) //FIXME should this be here or moved into ActorCell.start perhaps?
+      systemDispatch(actor, Create()) //FIXME should this be here or moved into ActorCell.start perhaps?
     } else System.err.println("Couldn't register: " + actor)
   }
 
@@ -258,7 +250,7 @@ abstract class MessageDispatcher(val app: AkkaApplication) extends Serializable
   /**
    *   Will be called when the dispatcher is to queue an invocation for execution
    */
-  protected[akka] def systemDispatch(invocation: SystemEnvelope)
+  protected[akka] def systemDispatch(receiver: ActorCell, invocation: SystemMessage)
 
   /**
    *   Will be called when the dispatcher is to queue an invocation for execution

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

@@ -54,7 +54,7 @@ class BalancingDispatcher(
 
   protected[akka] override def createMailbox(actor: ActorCell): Mailbox = new SharingMailbox(actor)
 
-  class SharingMailbox(val actor: ActorCell) extends Mailbox with DefaultSystemMessageQueue {
+  class SharingMailbox(_actor: ActorCell) extends Mailbox(_actor) with DefaultSystemMessageQueue {
     final def enqueue(handle: Envelope) = messageQueue.enqueue(handle)
 
     final def dequeue(): Envelope = {

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

@@ -84,8 +84,8 @@ class Dispatcher(
     registerForExecution(mbox, true, false)
   }
 
-  protected[akka] def systemDispatch(invocation: SystemEnvelope) = {
+  protected[akka] def systemDispatch(receiver: ActorCell, invocation: SystemMessage) = {
-    val mbox = invocation.receiver.mailbox
+    val mbox = receiver.mailbox
     mbox systemEnqueue invocation
     registerForExecution(mbox, false, true)
   }
@@ -100,7 +100,7 @@ class Dispatcher(
     }
   }
 
-  protected[akka] def createMailbox(actor: ActorCell): Mailbox = mailboxType.create(this)
+  protected[akka] def createMailbox(actor: ActorCell): Mailbox = mailboxType.create(this, actor)
 
   protected[akka] def start {}
 

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

@@ -8,7 +8,7 @@ import akka.AkkaException
 import java.util.{ Comparator, PriorityQueue }
 import akka.util._
 import java.util.Queue
-import akka.actor.ActorContext
+import akka.actor.{ ActorContext, ActorCell }
 import java.util.concurrent._
 import atomic.{ AtomicInteger, AtomicReferenceFieldUpdater }
 import annotation.tailrec
@@ -34,7 +34,7 @@ private[dispatch] object Mailbox {
 /**
  * @author <a href="http://jonasboner.com">Jonas Bon&#233;r</a>
  */
-abstract class Mailbox extends AbstractMailbox with MessageQueue with SystemMessageQueue with Runnable {
+abstract class Mailbox(val actor: ActorCell) extends AbstractMailbox with MessageQueue with SystemMessageQueue with Runnable {
   import Mailbox._
 
   @inline
@@ -186,7 +186,7 @@ abstract class Mailbox extends AbstractMailbox with MessageQueue with SystemMess
   def processAllSystemMessages() {
     var nextMessage = systemDequeue()
     while (nextMessage ne null) {
-      nextMessage.invoke()
+      actor systemInvoke nextMessage
       nextMessage = systemDequeue()
     }
   }
@@ -208,19 +208,20 @@ trait MessageQueue {
 }
 
 trait SystemMessageQueue {
-  def systemEnqueue(handle: SystemEnvelope): Unit
+  def systemEnqueue(message: SystemMessage): Unit
 
-  def systemDequeue(): SystemEnvelope
+  def systemDequeue(): SystemMessage
 
   def hasSystemMessages: Boolean
 }
 
 trait DefaultSystemMessageQueue { self: SystemMessageQueue ⇒
-  final val systemMessages = new ConcurrentLinkedQueue[SystemEnvelope]()
 
-  def systemEnqueue(handle: SystemEnvelope): Unit = systemMessages offer handle
+  final val systemMessages = new ConcurrentLinkedQueue[SystemMessage]()
 
-  def systemDequeue(): SystemEnvelope = systemMessages.poll()
+  def systemEnqueue(message: SystemMessage): Unit = systemMessages offer message
+
+  def systemDequeue(): SystemMessage = systemMessages.poll()
 
   def hasSystemMessages: Boolean = !systemMessages.isEmpty
 }
@@ -255,17 +256,18 @@ trait QueueBasedMessageQueue extends MessageQueue {
  * Mailbox configuration.
  */
 trait MailboxType {
-  def create(dispatcher: MessageDispatcher): Mailbox
+  def create(dispatcher: MessageDispatcher, receiver: ActorCell): Mailbox
 }
 
 /**
  * It's a case class for Java (new UnboundedMailbox)
  */
 case class UnboundedMailbox() extends MailboxType {
-  override def create(_dispatcher: MessageDispatcher) = new Mailbox with QueueBasedMessageQueue with UnboundedMessageQueueSemantics with DefaultSystemMessageQueue {
+  override def create(_dispatcher: MessageDispatcher, receiver: ActorCell) =
-    final val queue = new ConcurrentLinkedQueue[Envelope]()
+    new Mailbox(receiver) with QueueBasedMessageQueue with UnboundedMessageQueueSemantics with DefaultSystemMessageQueue {
-    final val dispatcher = _dispatcher
+      final val queue = new ConcurrentLinkedQueue[Envelope]()
-  }
+      final val dispatcher = _dispatcher
+    }
 }
 
 case class BoundedMailbox( final val capacity: Int, final val pushTimeOut: Duration) extends MailboxType {
@@ -273,18 +275,20 @@ case class BoundedMailbox( final val capacity: Int, final val pushTimeOut: Durat
   if (capacity < 0) throw new IllegalArgumentException("The capacity for BoundedMailbox can not be negative")
   if (pushTimeOut eq null) throw new IllegalArgumentException("The push time-out for BoundedMailbox can not be null")
 
-  override def create(_dispatcher: MessageDispatcher) = new Mailbox with QueueBasedMessageQueue with BoundedMessageQueueSemantics with DefaultSystemMessageQueue {
+  override def create(_dispatcher: MessageDispatcher, receiver: ActorCell) =
-    final val queue = new LinkedBlockingQueue[Envelope](capacity)
+    new Mailbox(receiver) with QueueBasedMessageQueue with BoundedMessageQueueSemantics with DefaultSystemMessageQueue {
-    final val pushTimeOut = BoundedMailbox.this.pushTimeOut
+      final val queue = new LinkedBlockingQueue[Envelope](capacity)
-    final val dispatcher = _dispatcher
+      final val pushTimeOut = BoundedMailbox.this.pushTimeOut
-  }
+      final val dispatcher = _dispatcher
+    }
 }
 
 case class UnboundedPriorityMailbox( final val cmp: Comparator[Envelope]) extends MailboxType {
-  override def create(_dispatcher: MessageDispatcher) = new Mailbox with QueueBasedMessageQueue with UnboundedMessageQueueSemantics with DefaultSystemMessageQueue {
+  override def create(_dispatcher: MessageDispatcher, receiver: ActorCell) =
-    final val queue = new PriorityBlockingQueue[Envelope](11, cmp)
+    new Mailbox(receiver) with QueueBasedMessageQueue with UnboundedMessageQueueSemantics with DefaultSystemMessageQueue {
-    final val dispatcher = _dispatcher
+      final val queue = new PriorityBlockingQueue[Envelope](11, cmp)
-  }
+      final val dispatcher = _dispatcher
+    }
 }
 
 case class BoundedPriorityMailbox( final val cmp: Comparator[Envelope], final val capacity: Int, final val pushTimeOut: Duration) extends MailboxType {
@@ -292,10 +296,11 @@ case class BoundedPriorityMailbox( final val cmp: Comparator[Envelope], final va
   if (capacity < 0) throw new IllegalArgumentException("The capacity for BoundedMailbox can not be negative")
   if (pushTimeOut eq null) throw new IllegalArgumentException("The push time-out for BoundedMailbox can not be null")
 
-  override def create(_dispatcher: MessageDispatcher) = new Mailbox with QueueBasedMessageQueue with BoundedMessageQueueSemantics with DefaultSystemMessageQueue {
+  override def create(_dispatcher: MessageDispatcher, receiver: ActorCell) =
-    final val queue = new BoundedBlockingQueue[Envelope](capacity, new PriorityQueue[Envelope](11, cmp))
+    new Mailbox(receiver) with QueueBasedMessageQueue with BoundedMessageQueueSemantics with DefaultSystemMessageQueue {
-    final val pushTimeOut = BoundedPriorityMailbox.this.pushTimeOut
+      final val queue = new BoundedBlockingQueue[Envelope](capacity, new PriorityQueue[Envelope](11, cmp))
-    final val dispatcher = _dispatcher
+      final val pushTimeOut = BoundedPriorityMailbox.this.pushTimeOut
-  }
+      final val dispatcher = _dispatcher
+    }
 }
 

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

@@ -106,7 +106,7 @@ object CallingThreadDispatcher {
 class CallingThreadDispatcher(_app: AkkaApplication, val name: String = "calling-thread", val warnings: Boolean = true) extends MessageDispatcher(_app) {
   import CallingThreadDispatcher._
 
-  protected[akka] override def createMailbox(actor: ActorCell) = new CallingThreadMailbox(this)
+  protected[akka] override def createMailbox(actor: ActorCell) = new CallingThreadMailbox(this, actor)
 
   private def getMailbox(actor: ActorCell) = actor.mailbox.asInstanceOf[CallingThreadMailbox]
 
@@ -140,11 +140,11 @@ class CallingThreadDispatcher(_app: AkkaApplication, val name: String = "calling
 
   override def mailboxIsEmpty(actor: ActorCell): Boolean = getMailbox(actor).queue.isEmpty
 
-  protected[akka] override def systemDispatch(handle: SystemEnvelope) {
+  protected[akka] override def systemDispatch(receiver: ActorCell, message: SystemMessage) {
-    val mbox = getMailbox(handle.receiver)
+    val mbox = getMailbox(receiver)
     mbox.lock.lock
     try {
-      handle.invoke()
+      receiver systemInvoke message
     } finally {
       mbox.lock.unlock
     }
@@ -241,7 +241,7 @@ class NestingQueue {
   def isActive = active
 }
 
-class CallingThreadMailbox(val dispatcher: MessageDispatcher) extends Mailbox with DefaultSystemMessageQueue {
+class CallingThreadMailbox(val dispatcher: MessageDispatcher, _receiver: ActorCell) extends Mailbox(_receiver) with DefaultSystemMessageQueue {
 
   private val q = new ThreadLocal[NestingQueue]() {
     override def initialValue = new NestingQueue