From c447f462249f58b823bd1a229d5fa45525d2c949 Mon Sep 17 00:00:00 2001
From: Patrik Nordwall <patrik.nordwall@gmail.com>
Date: Wed, 1 Feb 2012 14:40:12 +0100
Subject: [PATCH] Some polish on the error handling. See #1310

---
 ...{NonFatalSpec.scala => HarmlessSpec.scala} | 26 +++++++-----
 .../src/main/scala/akka/actor/ActorCell.scala | 32 +++++++--------
 .../main/scala/akka/actor/ActorSystem.scala   |  4 +-
 .../main/scala/akka/actor/TypedActor.scala    |  4 +-
 .../akka/dispatch/AbstractDispatcher.scala    |  4 +-
 .../src/main/scala/akka/dispatch/Future.scala | 37 +++++++++--------
 .../main/scala/akka/dispatch/Mailbox.scala    |  2 +-
 .../src/main/scala/akka/util/Harmless.scala   | 29 +++++++++++++
 .../src/main/scala/akka/util/NonFatal.scala   | 41 -------------------
 .../actor/mailbox/FiledBasedMailbox.scala     |  6 +--
 .../actor/mailbox/filequeue/Journal.scala     |  3 +-
 .../actor/mailbox/RedisBasedMailbox.scala     |  5 ++-
 .../actor/mailbox/ZooKeeperBasedMailbox.scala |  3 +-
 .../remote/netty/NettyRemoteSupport.scala     |  6 +--
 .../testkit/CallingThreadDispatcher.scala     | 12 +++---
 15 files changed, 101 insertions(+), 113 deletions(-)
 rename akka-actor-tests/src/test/scala/akka/util/{NonFatalSpec.scala => HarmlessSpec.scala} (62%)
 create mode 100644 akka-actor/src/main/scala/akka/util/Harmless.scala
 delete mode 100644 akka-actor/src/main/scala/akka/util/NonFatal.scala

diff --git a/akka-actor-tests/src/test/scala/akka/util/NonFatalSpec.scala b/akka-actor-tests/src/test/scala/akka/util/HarmlessSpec.scala
similarity index 62%
rename from akka-actor-tests/src/test/scala/akka/util/NonFatalSpec.scala
rename to akka-actor-tests/src/test/scala/akka/util/HarmlessSpec.scala
index c7d93b4b01..5ac96c2d34 100644
--- a/akka-actor-tests/src/test/scala/akka/util/NonFatalSpec.scala
+++ b/akka-actor-tests/src/test/scala/akka/util/HarmlessSpec.scala
@@ -7,15 +7,15 @@ import org.scalatest.matchers.MustMatchers
 import akka.testkit.AkkaSpec
 
 @org.junit.runner.RunWith(classOf[org.scalatest.junit.JUnitRunner])
-class NonFatalSpec extends AkkaSpec with MustMatchers {
+class HarmlessSpec extends AkkaSpec with MustMatchers {
 
-  "A NonFatal extractor" must {
+  "A Harmless extractor" must {
 
     "match ordinary RuntimeException" in {
       try {
         throw new RuntimeException("Boom")
       } catch {
-        case NonFatal(e) ⇒ // as expected
+        case Harmless(e) ⇒ // as expected
       }
     }
 
@@ -29,7 +29,7 @@ class NonFatalSpec extends AkkaSpec with MustMatchers {
         try {
           blowUp(0)
         } catch {
-          case NonFatal(e) ⇒ assert(false)
+          case Harmless(e) ⇒ assert(false)
         }
       }
     }
@@ -39,22 +39,26 @@ class NonFatalSpec extends AkkaSpec with MustMatchers {
         try {
           throw new InterruptedException("Simulated InterruptedException")
         } catch {
-          case NonFatal(e) ⇒ assert(false)
+          case Harmless(e) ⇒ assert(false)
         }
       }
     }
 
-  }
-
-  "A NonFatalOrInterrupted extractor" must {
-
-    "match InterruptedException" in {
+    "be used together with InterruptedException" in {
       try {
         throw new InterruptedException("Simulated InterruptedException")
       } catch {
-        case NonFatalOrInterrupted(e) ⇒ // as expected
+        case _: InterruptedException ⇒ // as expected
+        case Harmless(e)             ⇒ assert(false)
+      }
+
+      try {
+        throw new RuntimeException("Simulated RuntimeException")
+      } catch {
+        case Harmless(_) | _: InterruptedException ⇒ // as expected
       }
     }
 
   }
+
 }
\ No newline at end of file
diff --git a/akka-actor/src/main/scala/akka/actor/ActorCell.scala b/akka-actor/src/main/scala/akka/actor/ActorCell.scala
index 089b187354..c445b7b35c 100644
--- a/akka-actor/src/main/scala/akka/actor/ActorCell.scala
+++ b/akka-actor/src/main/scala/akka/actor/ActorCell.scala
@@ -14,8 +14,7 @@ import akka.util.{ Duration, Helpers }
 import akka.japi.Procedure
 import java.io.{ NotSerializableException, ObjectOutputStream }
 import akka.serialization.SerializationExtension
-import akka.util.NonFatal
-import akka.util.NonFatalOrInterrupted
+import akka.util.Harmless
 
 //TODO: everything here for current compatibility - could be limited more
 
@@ -364,7 +363,7 @@ private[akka] class ActorCell(
       checkReceiveTimeout
       if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, clazz(created), "started (" + created + ")"))
     } catch {
-      case NonFatal(e) ⇒
+      case Harmless(e) ⇒
         try {
           system.eventStream.publish(Error(e, self.path.toString, clazz(actor), "error while creating actor"))
           // prevent any further messages to be processed until the actor has been restarted
@@ -396,7 +395,7 @@ private[akka] class ActorCell(
 
       actor.supervisorStrategy.handleSupervisorRestarted(cause, self, children)
     } catch {
-      case NonFatal(e) ⇒ try {
+      case Harmless(e) ⇒ try {
         system.eventStream.publish(Error(e, self.path.toString, clazz(actor), "error while creating actor"))
         // prevent any further messages to be processed until the actor has been restarted
         dispatcher.suspend(this)
@@ -460,7 +459,7 @@ private[akka] class ActorCell(
         case ChildTerminated(child) ⇒ handleChildTerminated(child)
       }
     } catch {
-      case NonFatal(e) ⇒
+      case Harmless(e) ⇒
         system.eventStream.publish(Error(e, self.path.toString, clazz(actor), "error while processing " + message))
         //TODO FIXME How should problems here be handled???
         throw e
@@ -482,26 +481,23 @@ private[akka] class ActorCell(
           }
           currentMessage = null // reset current message after successful invocation
         } catch {
-          case NonFatalOrInterrupted(e) ⇒
+          case e: InterruptedException ⇒
+            // make sure that InterruptedException does not leave this thread
+            val ex = ActorInterruptedException(e)
+            actor.supervisorStrategy.handleSupervisorFailing(self, children)
+            parent.tell(Failed(ex), self)
+            throw e //Re-throw InterruptedExceptions as expected
+          case Harmless(e) ⇒
             system.eventStream.publish(Error(e, self.path.toString, clazz(actor), e.getMessage))
             // prevent any further messages to be processed until the actor has been restarted
             dispatcher.suspend(this)
-            e match {
-              case ie: InterruptedException ⇒
-                // make sure that InterruptedException does not leave this thread
-                val ex = ActorInterruptedException(ie)
-                actor.supervisorStrategy.handleSupervisorFailing(self, children)
-                parent.tell(Failed(ex), self)
-                throw ie //Re-throw InterruptedExceptions as expected
-              case _ ⇒
-                actor.supervisorStrategy.handleSupervisorFailing(self, children)
-                parent.tell(Failed(e), self)
-            }
+            actor.supervisorStrategy.handleSupervisorFailing(self, children)
+            parent.tell(Failed(e), self)
         } finally {
           checkReceiveTimeout // Reschedule receive timeout
         }
       } catch {
-        case NonFatal(e) ⇒
+        case Harmless(e) ⇒
           system.eventStream.publish(Error(e, self.path.toString, clazz(actor), e.getMessage))
           throw e
       }
diff --git a/akka-actor/src/main/scala/akka/actor/ActorSystem.scala b/akka-actor/src/main/scala/akka/actor/ActorSystem.scala
index 473649a3fb..9087781d58 100644
--- a/akka-actor/src/main/scala/akka/actor/ActorSystem.scala
+++ b/akka-actor/src/main/scala/akka/actor/ActorSystem.scala
@@ -346,8 +346,8 @@ class ActorSystemImpl(val name: String, applicationConfig: Config) extends Exten
       def uncaughtException(thread: Thread, cause: Throwable): Unit = {
         log.error(cause, "Uncaught error from thread [{}]", thread.getName)
         cause match {
-          case NonFatalOrInterrupted(e) ⇒
-          case _                        ⇒ shutdown()
+          case Harmless(_) | _: InterruptedException ⇒
+          case _                                     ⇒ shutdown()
         }
       }
     }
diff --git a/akka-actor/src/main/scala/akka/actor/TypedActor.scala b/akka-actor/src/main/scala/akka/actor/TypedActor.scala
index 300949b277..64818561af 100644
--- a/akka-actor/src/main/scala/akka/actor/TypedActor.scala
+++ b/akka-actor/src/main/scala/akka/actor/TypedActor.scala
@@ -6,7 +6,7 @@ package akka.actor
 
 import akka.japi.{ Creator, Option ⇒ JOption }
 import java.lang.reflect.{ InvocationTargetException, Method, InvocationHandler, Proxy }
-import akka.util.{ Timeout, NonFatal }
+import akka.util.{ Timeout, Harmless }
 import java.util.concurrent.atomic.{ AtomicReference ⇒ AtomVar }
 import akka.serialization.{ Serialization, SerializationExtension }
 import akka.dispatch._
@@ -270,7 +270,7 @@ object TypedActor extends ExtensionId[TypedActorExtension] with ExtensionIdProvi
                 sender ! m(me)
               }
             } catch {
-              case NonFatal(e) ⇒
+              case Harmless(e) ⇒
                 sender ! Status.Failure(e)
                 throw e
             }
diff --git a/akka-actor/src/main/scala/akka/dispatch/AbstractDispatcher.scala b/akka-actor/src/main/scala/akka/dispatch/AbstractDispatcher.scala
index bc1494a6b2..d029791f8a 100644
--- a/akka-actor/src/main/scala/akka/dispatch/AbstractDispatcher.scala
+++ b/akka-actor/src/main/scala/akka/dispatch/AbstractDispatcher.scala
@@ -15,7 +15,7 @@ import com.typesafe.config.Config
 import akka.util.ReflectiveAccess
 import akka.serialization.SerializationExtension
 import akka.jsr166y.ForkJoinPool
-import akka.util.NonFatal
+import akka.util.Harmless
 
 final case class Envelope(val message: Any, val sender: ActorRef)(system: ActorSystem) {
   if (message.isInstanceOf[AnyRef]) {
@@ -81,7 +81,7 @@ final case class TaskInvocation(eventStream: EventStream, runnable: Runnable, cl
     try {
       runnable.run()
     } catch {
-      case NonFatal(e) ⇒
+      case Harmless(e) ⇒
         eventStream.publish(Error(e, "TaskInvocation", this.getClass, e.getMessage))
     } finally {
       cleanup()
diff --git a/akka-actor/src/main/scala/akka/dispatch/Future.scala b/akka-actor/src/main/scala/akka/dispatch/Future.scala
index 218b3035ea..d2b5be434b 100644
--- a/akka-actor/src/main/scala/akka/dispatch/Future.scala
+++ b/akka-actor/src/main/scala/akka/dispatch/Future.scala
@@ -17,7 +17,7 @@ import akka.util.{ Duration, BoxedType }
 import java.util.concurrent.atomic.{ AtomicReferenceFieldUpdater, AtomicInteger }
 import akka.dispatch.Await.CanAwait
 import java.util.concurrent._
-import akka.util.NonFatal
+import akka.util.Harmless
 
 object Await {
   sealed trait CanAwait
@@ -142,7 +142,7 @@ object Future {
           try {
             Right(body)
           } catch {
-            case NonFatal(e) ⇒ Left(e)
+            case Harmless(e) ⇒ Left(e)
           }
         }
     })
@@ -322,19 +322,19 @@ object Future {
                 try {
                   next.apply()
                 } catch {
-                  case NonFatal(e) ⇒
-                    executor match {
-                      case m: MessageDispatcher ⇒
-                        m.prerequisites.eventStream.publish(Error(e, "Future.dispatchTask", this.getClass, e.getMessage))
-                      case other ⇒
-                        // TODO printStackTrace
-                        e.printStackTrace()
-                    }
+                  case Harmless(e) ⇒ logError("Future.dispatchTask", e)
                 }
               }
             } finally { _taskStack.remove() }
         })
     }
+
+  private def logError(logSource: String, problem: Throwable)(implicit executor: ExecutionContext): Unit = {
+    executor match {
+      case m: MessageDispatcher ⇒ m.prerequisites.eventStream.publish(Error(problem, logSource, this.getClass, problem.getMessage))
+      case other                ⇒ problem.printStackTrace()
+    }
+  }
 }
 
 sealed trait Future[+T] extends japi.Future[T] with Await.Awaitable[T] {
@@ -489,7 +489,7 @@ sealed trait Future[+T] extends japi.Future[T] with Await.Awaitable[T] {
         future complete (try {
           Right(f(res))
         } catch {
-          case NonFatal(e) ⇒ Left(e)
+          case Harmless(e) ⇒ Left(e)
         })
     }
     future
@@ -536,7 +536,8 @@ sealed trait Future[+T] extends japi.Future[T] with Await.Awaitable[T] {
         try {
           p completeWith f(r)
         } catch {
-          case NonFatal(e) ⇒ p complete Left(e)
+          case Harmless(e) ⇒ p complete Left(e)
+          case t           ⇒ p complete Left(new ExecutionException(t)); throw t
         }
     }
     p
@@ -574,15 +575,15 @@ sealed trait Future[+T] extends japi.Future[T] with Await.Awaitable[T] {
       case r @ Right(res) ⇒ p complete (try {
         if (pred(res)) r else Left(new MatchError(res))
       } catch {
-        case NonFatal(e) ⇒ Left(e)
+        case Harmless(e) ⇒ Left(e)
       })
     }
     p
   }
 
-  protected def logError(msg: String, problem: Throwable): Unit = {
+  protected def logError(logSource: String, problem: Throwable): Unit = {
     executor match {
-      case m: MessageDispatcher ⇒ m.prerequisites.eventStream.publish(Error(problem, msg, this.getClass, problem.getMessage))
+      case m: MessageDispatcher ⇒ m.prerequisites.eventStream.publish(Error(problem, logSource, this.getClass, problem.getMessage))
       case other                ⇒ problem.printStackTrace()
     }
   }
@@ -660,7 +661,7 @@ trait Promise[T] extends Future[T] {
       try {
         fr completeWith cont(thisPromise)
       } catch {
-        case NonFatal(e) ⇒ fr failure e
+        case Harmless(e) ⇒ fr failure e
       }
     }
     fr
@@ -673,7 +674,7 @@ trait Promise[T] extends Future[T] {
       try {
         fr completeWith cont(f)
       } catch {
-        case NonFatal(e) ⇒ fr failure e
+        case Harmless(e) ⇒ fr failure e
       }
     }
     fr
@@ -781,7 +782,7 @@ class DefaultPromise[T](implicit val executor: ExecutionContext) extends Abstrac
   }
 
   private final def notifyCompleted(func: Either[Throwable, T] ⇒ Unit, result: Either[Throwable, T]) {
-    try { func(result) } catch { case NonFatal(e) ⇒ logError("Future onComplete-callback raised an exception", e) }
+    try { func(result) } catch { case Harmless(e) ⇒ logError("Future.onComplete", e) }
   }
 }
 
diff --git a/akka-actor/src/main/scala/akka/dispatch/Mailbox.scala b/akka-actor/src/main/scala/akka/dispatch/Mailbox.scala
index 0f42ffa4e4..7489b59a98 100644
--- a/akka-actor/src/main/scala/akka/dispatch/Mailbox.scala
+++ b/akka-actor/src/main/scala/akka/dispatch/Mailbox.scala
@@ -197,7 +197,7 @@ private[akka] abstract class Mailbox(val actor: ActorCell) extends MessageQueue
         if (nextMessage eq null) nextMessage = systemDrain()
       }
     } catch {
-      case NonFatal(e) ⇒
+      case Harmless(e) ⇒
         actor.system.eventStream.publish(Error(e, actor.self.path.toString, this.getClass, "exception during processing system messages, dropping " + SystemMessage.size(nextMessage) + " messages!"))
         throw e
     }
diff --git a/akka-actor/src/main/scala/akka/util/Harmless.scala b/akka-actor/src/main/scala/akka/util/Harmless.scala
new file mode 100644
index 0000000000..6a15538f2d
--- /dev/null
+++ b/akka-actor/src/main/scala/akka/util/Harmless.scala
@@ -0,0 +1,29 @@
+/**
+ * Copyright (C) 2009-2012 Typesafe Inc. <http://www.typesafe.com>
+ */
+package akka.util
+
+/**
+ * Extractor of harmless Throwables. Will not match fatal errors
+ * like VirtualMachineError (OutOfMemoryError, StackOverflowError)
+ * ThreadDeath, and InterruptedException.
+ *
+ * Usage to catch all harmless throwables:
+ * {{{
+ *   try {
+ *     // dangerous stuff
+ *   } catch {
+ *     case Harmless(e) => log.error(e, "Something not that bad")
+ *   }
+ * }}}
+ */
+object Harmless {
+
+  def unapply(t: Throwable): Option[Throwable] = t match {
+    // VirtualMachineError includes OutOfMemoryError, StackOverflowError and other fatal errors
+    case _: VirtualMachineError | _: ThreadDeath | _: InterruptedException ⇒ None
+    case e ⇒ Some(e)
+  }
+
+}
+
diff --git a/akka-actor/src/main/scala/akka/util/NonFatal.scala b/akka-actor/src/main/scala/akka/util/NonFatal.scala
deleted file mode 100644
index b4bbbaed27..0000000000
--- a/akka-actor/src/main/scala/akka/util/NonFatal.scala
+++ /dev/null
@@ -1,41 +0,0 @@
-/**
- * Copyright (C) 2009-2012 Typesafe Inc. <http://www.typesafe.com>
- */
-package akka.util
-
-/**
- * Extractor of non-fatal Throwables. Will not match
- * VirtualMachineError (OutOfMemoryError, StackOverflowError)
- * and InterruptedException.
- *
- * Usage to catch all non-fatal throwables:
- * {{{
- *   try {
- *     // dangerous stuff
- *   } catch {
- *     case NonFatal(e) => log.error(e, "Something not that bad")
- *   }
- * }}}
- */
-object NonFatal {
-
-  def unapply(t: Throwable): Option[Throwable] = t match {
-    // VirtualMachineError includes OutOfMemoryError, StackOverflowError and other fatal errors
-    case e: VirtualMachineError  ⇒ None
-    case e: ThreadDeath          ⇒ None
-    case e: InterruptedException ⇒ None
-    case e                       ⇒ Some(e)
-  }
-
-}
-
-/**
- * Match InterruptedException and the same as
- * [[akka.util.NonFatal]].
- */
-object NonFatalOrInterrupted {
-  def unapply(t: Throwable): Option[Throwable] = t match {
-    case e: InterruptedException ⇒ Some(e)
-    case e                       ⇒ NonFatal.unapply(t)
-  }
-}
\ No newline at end of file
diff --git a/akka-durable-mailboxes/akka-file-mailbox/src/main/scala/akka/actor/mailbox/FiledBasedMailbox.scala b/akka-durable-mailboxes/akka-file-mailbox/src/main/scala/akka/actor/mailbox/FiledBasedMailbox.scala
index 0f18f1ec58..320e63233a 100644
--- a/akka-durable-mailboxes/akka-file-mailbox/src/main/scala/akka/actor/mailbox/FiledBasedMailbox.scala
+++ b/akka-durable-mailboxes/akka-file-mailbox/src/main/scala/akka/actor/mailbox/FiledBasedMailbox.scala
@@ -11,6 +11,7 @@ import akka.event.Logging
 import akka.actor.ActorRef
 import akka.dispatch.MailboxType
 import com.typesafe.config.Config
+import akka.util.Harmless
 
 class FileBasedMailboxType(config: Config) extends MailboxType {
   override def create(owner: ActorContext) = new FileBasedMailbox(owner)
@@ -24,7 +25,7 @@ class FileBasedMailbox(val owner: ActorContext) extends DurableMailbox(owner) wi
   val queuePath = settings.QueuePath
 
   private val queue = try {
-    try { FileUtils.forceMkdir(new java.io.File(queuePath)) } catch { case e ⇒ {} }
+    try { FileUtils.forceMkdir(new java.io.File(queuePath)) } catch { case Harmless(_) ⇒ {} }
     val queue = new filequeue.PersistentQueue(queuePath, name, settings, log)
     queue.setup // replays journal
     queue.discardExpired
@@ -68,8 +69,7 @@ class FileBasedMailbox(val owner: ActorContext) extends DurableMailbox(owner) wi
     queue.remove
     true
   } catch {
-    // TODO catching all and continue isn't good for OOME, ticket #1418
-    case e ⇒ false
+    case Harmless(_) ⇒ false
   }
 
 }
diff --git a/akka-durable-mailboxes/akka-file-mailbox/src/main/scala/akka/actor/mailbox/filequeue/Journal.scala b/akka-durable-mailboxes/akka-file-mailbox/src/main/scala/akka/actor/mailbox/filequeue/Journal.scala
index 6b8fa8c568..64aba1b4af 100644
--- a/akka-durable-mailboxes/akka-file-mailbox/src/main/scala/akka/actor/mailbox/filequeue/Journal.scala
+++ b/akka-durable-mailboxes/akka-file-mailbox/src/main/scala/akka/actor/mailbox/filequeue/Journal.scala
@@ -21,6 +21,7 @@ import java.io._
 import java.nio.{ ByteBuffer, ByteOrder }
 import java.nio.channels.FileChannel
 import akka.event.LoggingAdapter
+import akka.util.Harmless
 
 // returned from journal replay
 sealed trait JournalItem
@@ -99,7 +100,7 @@ class Journal(queuePath: String, syncJournal: ⇒ Boolean, log: LoggingAdapter)
       close()
       queueFile.delete
     } catch {
-      case _ ⇒
+      case Harmless(_) ⇒
     }
   }
 
diff --git a/akka-durable-mailboxes/akka-redis-mailbox/src/main/scala/akka/actor/mailbox/RedisBasedMailbox.scala b/akka-durable-mailboxes/akka-redis-mailbox/src/main/scala/akka/actor/mailbox/RedisBasedMailbox.scala
index 3c33663b73..38493d2ceb 100644
--- a/akka-durable-mailboxes/akka-redis-mailbox/src/main/scala/akka/actor/mailbox/RedisBasedMailbox.scala
+++ b/akka-durable-mailboxes/akka-redis-mailbox/src/main/scala/akka/actor/mailbox/RedisBasedMailbox.scala
@@ -11,6 +11,7 @@ import akka.event.Logging
 import akka.actor.ActorRef
 import akka.dispatch.MailboxType
 import com.typesafe.config.Config
+import akka.util.Harmless
 
 class RedisBasedMailboxException(message: String) extends AkkaException(message)
 
@@ -47,7 +48,7 @@ class RedisBasedMailbox(val owner: ActorContext) extends DurableMailbox(owner) w
       envelope
     } catch {
       case e: java.util.NoSuchElementException ⇒ null
-      case e ⇒
+      case Harmless(e) ⇒
         log.error(e, "Couldn't dequeue from Redis-based mailbox")
         throw e
     }
@@ -73,7 +74,7 @@ class RedisBasedMailbox(val owner: ActorContext) extends DurableMailbox(owner) w
         clients = connect()
         body
       }
-      case e ⇒
+      case Harmless(e) ⇒
         val error = new RedisBasedMailboxException("Could not connect to Redis server, due to: " + e.getMessage)
         log.error(error, error.getMessage)
         throw error
diff --git a/akka-durable-mailboxes/akka-zookeeper-mailbox/src/main/scala/akka/actor/mailbox/ZooKeeperBasedMailbox.scala b/akka-durable-mailboxes/akka-zookeeper-mailbox/src/main/scala/akka/actor/mailbox/ZooKeeperBasedMailbox.scala
index 1420a8a543..4b197689bb 100644
--- a/akka-durable-mailboxes/akka-zookeeper-mailbox/src/main/scala/akka/actor/mailbox/ZooKeeperBasedMailbox.scala
+++ b/akka-durable-mailboxes/akka-zookeeper-mailbox/src/main/scala/akka/actor/mailbox/ZooKeeperBasedMailbox.scala
@@ -12,6 +12,7 @@ import akka.cluster.zookeeper.ZooKeeperQueue
 import akka.actor.ActorRef
 import akka.dispatch.MailboxType
 import com.typesafe.config.Config
+import akka.util.Harmless
 
 class ZooKeeperBasedMailboxException(message: String) extends AkkaException(message)
 
@@ -45,7 +46,7 @@ class ZooKeeperBasedMailbox(val owner: ActorContext) extends DurableMailbox(owne
   } catch {
     case e: java.util.NoSuchElementException ⇒ null
     case e: InterruptedException             ⇒ null
-    case e ⇒
+    case Harmless(e) ⇒
       log.error(e, "Couldn't dequeue from ZooKeeper-based mailbox, due to: " + e.getMessage)
       throw e
   }
diff --git a/akka-remote/src/main/scala/akka/remote/netty/NettyRemoteSupport.scala b/akka-remote/src/main/scala/akka/remote/netty/NettyRemoteSupport.scala
index e9fe83dd7e..f9131338bf 100644
--- a/akka-remote/src/main/scala/akka/remote/netty/NettyRemoteSupport.scala
+++ b/akka-remote/src/main/scala/akka/remote/netty/NettyRemoteSupport.scala
@@ -9,21 +9,19 @@ import java.util.concurrent.atomic.AtomicReference
 import java.util.concurrent.atomic.AtomicBoolean
 import java.util.concurrent.locks.ReentrantReadWriteLock
 import java.util.concurrent.Executors
-
 import scala.collection.mutable.HashMap
-
 import org.jboss.netty.channel.group.{ DefaultChannelGroup, ChannelGroupFuture }
 import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory
 import org.jboss.netty.channel.{ ChannelHandlerContext, Channel }
 import org.jboss.netty.handler.codec.protobuf.{ ProtobufEncoder, ProtobufDecoder }
 import org.jboss.netty.handler.execution.OrderedMemoryAwareThreadPoolExecutor
 import org.jboss.netty.util.HashedWheelTimer
-
 import akka.actor.{ Address, ActorSystemImpl, ActorRef }
 import akka.dispatch.MonitorableThreadFactory
 import akka.event.Logging
 import akka.remote.RemoteProtocol.AkkaRemoteProtocol
 import akka.remote.{ RemoteTransportException, RemoteTransport, RemoteSettings, RemoteMarshallingOps, RemoteActorRefProvider, RemoteActorRef }
+import akka.util.Harmless
 
 /**
  * Provides the implementation of the Netty remote support
@@ -80,7 +78,7 @@ class NettyRemoteTransport(val remoteSettings: RemoteSettings, val system: Actor
     try {
       remoteClients foreach {
         case (_, client) ⇒ try client.shutdown() catch {
-          case e ⇒ log.error(e, "failure while shutting down [{}]", client)
+          case Harmless(e) ⇒ log.error(e, "failure while shutting down [{}]", client)
         }
       }
       remoteClients.clear()
diff --git a/akka-testkit/src/main/scala/akka/testkit/CallingThreadDispatcher.scala b/akka-testkit/src/main/scala/akka/testkit/CallingThreadDispatcher.scala
index af2c44611a..70ec56f60b 100644
--- a/akka-testkit/src/main/scala/akka/testkit/CallingThreadDispatcher.scala
+++ b/akka-testkit/src/main/scala/akka/testkit/CallingThreadDispatcher.scala
@@ -6,15 +6,13 @@ package akka.testkit
 import java.lang.ref.WeakReference
 import java.util.concurrent.locks.ReentrantLock
 import java.util.LinkedList
-
 import scala.annotation.tailrec
-
 import com.typesafe.config.Config
-
 import akka.actor.{ ExtensionIdProvider, ExtensionId, Extension, ExtendedActorSystem, ActorRef, ActorCell }
 import akka.dispatch.{ TaskInvocation, SystemMessage, Suspend, Resume, MessageDispatcherConfigurator, MessageDispatcher, Mailbox, Envelope, DispatcherPrerequisites, DefaultSystemMessageQueue }
 import akka.util.duration.intToDurationInt
 import akka.util.{ Switch, Duration }
+import akka.util.Harmless
 
 /*
  * Locking rules:
@@ -225,7 +223,7 @@ class CallingThreadDispatcher(
             Thread.currentThread().interrupt()
             intex = ie
             true
-          case e ⇒
+          case Harmless(e) ⇒
             log.error(e, "Error during message processing")
             queue.leave
             false
@@ -235,7 +233,7 @@ class CallingThreadDispatcher(
         false
       } else false
     } catch {
-      case e ⇒ queue.leave; throw e
+      case Harmless(e) ⇒ queue.leave; throw e
     } finally {
       mbox.ctdLock.unlock
     }
@@ -294,8 +292,8 @@ class CallingThreadMailbox(_receiver: ActorCell) extends Mailbox(_receiver) with
 
   override def cleanUp(): Unit = {
     /*
-     * This is called from dispatcher.unregister, i.e. under this.lock. If 
-     * another thread obtained a reference to this mailbox and enqueues after 
+     * This is called from dispatcher.unregister, i.e. under this.lock. If
+     * another thread obtained a reference to this mailbox and enqueues after
      * the gather operation, tough luck: no guaranteed delivery to deadLetters.
      */
     suspendSwitch.locked {