improve DeadLetter reporting

(since I know now what’s causing these Jenkins failures ;-) )

- include recipient in DeadLetter
- include recipient in calls to enqueue/systemEnqueue
- move DeadLetterMailbox to ActorSystem (saves some space, too)
- hook up DeadLetterMailbox so it sends DeadLetters to app.deadLetters,
  which publishes them on the eventStream
- subscribe TestEventListener to DeadLetter and turn it into Warning

The generated warnings about ChildTerminated are very much correct, they
remind us that we still need to fix supervisor.stop() to await all
children’s death before actually committing suicide.

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

@@ -10,9 +10,8 @@ import java.util.concurrent.RejectedExecutionException
 import akka.util.Switch
 import java.lang.ref.WeakReference
 import scala.annotation.tailrec
-import akka.actor.ActorCell
+import akka.actor.{ ActorCell, ActorRef, ActorSystem }
 import akka.dispatch._
-import akka.actor.ActorSystem
 
 /*
  * Locking rules:
@@ -129,16 +128,17 @@ class CallingThreadDispatcher(_app: ActorSystem, val name: String = "calling-thr
   }
 
   override def resume(actor: ActorCell) {
-    val mboxopt = getMailbox(actor)
-    if (mboxopt.isEmpty) return
-    val mbox = mboxopt.get
-    val queue = mbox.queue
-    val wasActive = queue.isActive
-    val switched = mbox.suspendSwitch.switchOff {
-      gatherFromAllOtherQueues(mbox, queue)
-    }
-    if (switched && !wasActive) {
-      runQueue(mbox, queue)
+    actor.mailbox match {
+      case mbox: CallingThreadMailbox ⇒
+        val queue = mbox.queue
+        val wasActive = queue.isActive
+        val switched = mbox.suspendSwitch.switchOff {
+          gatherFromAllOtherQueues(mbox, queue)
+        }
+        if (switched && !wasActive) {
+          runQueue(mbox, queue)
+        }
+      case m ⇒ m.systemEnqueue(actor.self, Resume())
     }
   }
 
@@ -147,35 +147,37 @@ class CallingThreadDispatcher(_app: ActorSystem, val name: String = "calling-thr
   override def mailboxIsEmpty(actor: ActorCell): Boolean = getMailbox(actor) map (_.queue.isEmpty) getOrElse true
 
   protected[akka] override def systemDispatch(receiver: ActorCell, message: SystemMessage) {
-    val mboxopt = getMailbox(receiver)
-    if (mboxopt.isEmpty) return
-    val mbox = mboxopt.get
-    mbox.systemEnqueue(message)
-    val queue = mbox.queue
-    if (!queue.isActive) {
-      queue.enter
-      runQueue(mbox, queue)
+    receiver.mailbox match {
+      case mbox: CallingThreadMailbox ⇒
+        mbox.systemEnqueue(receiver.self, message)
+        val queue = mbox.queue
+        if (!queue.isActive) {
+          queue.enter
+          runQueue(mbox, queue)
+        }
+      case m ⇒ m.systemEnqueue(receiver.self, message)
     }
   }
 
   protected[akka] override def dispatch(receiver: ActorCell, handle: Envelope) {
-    val mboxopt = getMailbox(receiver)
-    if (mboxopt.isEmpty) return
-    val mbox = mboxopt.get
-    val queue = mbox.queue
-    val execute = mbox.suspendSwitch.fold {
-      queue.push(handle)
-      false
-    } {
-      queue.push(handle)
-      if (queue.isActive)
-        false
-      else {
-        queue.enter
-        true
-      }
+    receiver.mailbox match {
+      case mbox: CallingThreadMailbox ⇒
+        val queue = mbox.queue
+        val execute = mbox.suspendSwitch.fold {
+          queue.push(handle)
+          false
+        } {
+          queue.push(handle)
+          if (queue.isActive)
+            false
+          else {
+            queue.enter
+            true
+          }
+        }
+        if (execute) runQueue(mbox, queue)
+      case m ⇒ m.enqueue(receiver.self, handle)
     }
-    if (execute) runQueue(mbox, queue)
   }
 
   protected[akka] override def executeTask(invocation: TaskInvocation) { invocation.run }
@@ -270,7 +272,7 @@ class CallingThreadMailbox(val dispatcher: MessageDispatcher, _receiver: ActorCe
   val lock = new ReentrantLock
   val suspendSwitch = new Switch
 
-  override def enqueue(msg: Envelope) {}
+  override def enqueue(receiver: ActorRef, msg: Envelope) {}
   override def dequeue() = null
   override def hasMessages = true
   override def numberOfMessages = 0