add Class[_] to LogEvent

- it is customary to use class name for categorizing logs, hence we
  should support it; class is taken from logSource.getClass
- update SLF4J module to use logClass as category and set logSource in
  MDC "akkaSource"
- add docs

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

@@ -171,7 +171,7 @@ class FSMActorSpec extends AkkaSpec(Map("akka.actor.debug.fsm" -> true)) with Im
         system.eventStream.subscribe(testActor, classOf[Logging.Error])
         fsm ! "go"
         expectMsgPF(1 second, hint = "Next state 2 does not exist") {
-          case Logging.Error(_, `name`, "Next state 2 does not exist") ⇒ true
+          case Logging.Error(_, `name`, _, "Next state 2 does not exist") ⇒ true
         }
         system.eventStream.unsubscribe(testActor)
       }
@@ -221,15 +221,15 @@ class FSMActorSpec extends AkkaSpec(Map("akka.actor.debug.fsm" -> true)) with Im
             system.eventStream.subscribe(testActor, classOf[Logging.Debug])
             fsm ! "go"
             expectMsgPF(1 second, hint = "processing Event(go,null)") {
-              case Logging.Debug(`name`, s: String) if s.startsWith("processing Event(go,null) from Actor[") ⇒ true
+              case Logging.Debug(`name`, _, s: String) if s.startsWith("processing Event(go,null) from Actor[") ⇒ true
             }
-            expectMsg(1 second, Logging.Debug(name, "setting timer 't'/1500 milliseconds: Shutdown"))
-            expectMsg(1 second, Logging.Debug(name, "transition 1 -> 2"))
+            expectMsg(1 second, Logging.Debug(name, fsm.underlyingActor.getClass, "setting timer 't'/1500 milliseconds: Shutdown"))
+            expectMsg(1 second, Logging.Debug(name, fsm.underlyingActor.getClass, "transition 1 -> 2"))
             fsm ! "stop"
             expectMsgPF(1 second, hint = "processing Event(stop,null)") {
-              case Logging.Debug(`name`, s: String) if s.startsWith("processing Event(stop,null) from Actor[") ⇒ true
+              case Logging.Debug(`name`, _, s: String) if s.startsWith("processing Event(stop,null) from Actor[") ⇒ true
             }
-            expectMsgAllOf(1 second, Logging.Debug(name, "canceling timer 't'"), Normal)
+            expectMsgAllOf(1 second, Logging.Debug(name, fsm.underlyingActor.getClass, "canceling timer 't'"), Normal)
             expectNoMsg(1 second)
             system.eventStream.unsubscribe(testActor)
           }

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

@@ -151,7 +151,7 @@ object ActorModelSpec {
       await(deadline)(stops == dispatcher.stops.get)
     } catch {
       case e ⇒
-        system.eventStream.publish(Error(e, dispatcher.toString, "actual: stops=" + dispatcher.stops.get +
+        system.eventStream.publish(Error(e, dispatcher.toString, dispatcher.getClass, "actual: stops=" + dispatcher.stops.get +
           " required: stops=" + stops))
         throw e
     }
@@ -208,9 +208,11 @@ object ActorModelSpec {
       await(deadline)(stats.restarts.get() == restarts)
     } catch {
       case e ⇒
-        system.eventStream.publish(Error(e, Option(dispatcher).toString, "actual: " + stats + ", required: InterceptorStats(susp=" + suspensions +
-          ",res=" + resumes + ",reg=" + registers + ",unreg=" + unregisters +
-          ",recv=" + msgsReceived + ",proc=" + msgsProcessed + ",restart=" + restarts))
+        system.eventStream.publish(Error(e, Option(dispatcher).toString,
+          if (dispatcher ne null) dispatcher.getClass else this.getClass,
+          "actual: " + stats + ", required: InterceptorStats(susp=" + suspensions +
+            ",res=" + resumes + ",reg=" + registers + ",unreg=" + unregisters +
+            ",recv=" + msgsReceived + ",proc=" + msgsProcessed + ",restart=" + restarts))
         throw e
     }
   }
@@ -311,7 +313,7 @@ abstract class ActorModelSpec(config: String) extends AkkaSpec(config) with Defa
           try {
             f
           } catch {
-            case e ⇒ system.eventStream.publish(Error(e, "spawn", "error in spawned thread"))
+            case e ⇒ system.eventStream.publish(Error(e, "spawn", this.getClass, "error in spawned thread"))
           }
         }
       }

akka-actor-tests/src/test/scala/akka/event/EventStreamSpec.scala

@@ -108,7 +108,7 @@ class EventStreamSpec extends AkkaSpec(EventStreamSpec.config) {
 
   private def verifyLevel(bus: LoggingBus, level: Logging.LogLevel) {
     import Logging._
-    val allmsg = Seq(Debug("", "debug"), Info("", "info"), Warning("", "warning"), Error("", "error"))
+    val allmsg = Seq(Debug("", null, "debug"), Info("", null, "info"), Warning("", null, "warning"), Error("", null, "error"))
     val msg = allmsg filter (_.level <= level)
     allmsg foreach bus.publish
     msg foreach (x ⇒ expectMsg(x))

akka-actor-tests/src/test/scala/akka/event/LoggingReceiveSpec.scala

@@ -59,7 +59,7 @@ class LoggingReceiveSpec extends WordSpec with BeforeAndAfterEach with BeforeAnd
         }
         val log = LoggingReceive("funky")(r)
         log.isDefinedAt("hallo")
-        expectMsg(1 second, Logging.Debug("funky", "received unhandled message hallo"))
+        expectMsg(1 second, Logging.Debug("funky", classOf[String], "received unhandled message hallo"))
       }
     }
 
@@ -83,7 +83,7 @@ class LoggingReceiveSpec extends WordSpec with BeforeAndAfterEach with BeforeAnd
         val name = actor.path.toString
         actor ! "buh"
         within(1 second) {
-          expectMsg(Logging.Debug(name, "received handled message buh"))
+          expectMsg(Logging.Debug(name, actor.underlyingActor.getClass, "received handled message buh"))
           expectMsg("x")
         }
 
@@ -109,7 +109,7 @@ class LoggingReceiveSpec extends WordSpec with BeforeAndAfterEach with BeforeAnd
         })
         actor ! "buh"
         within(1 second) {
-          expectMsg(Logging.Debug(actor.path.toString, "received handled message buh"))
+          expectMsg(Logging.Debug(actor.path.toString, actor.underlyingActor.getClass, "received handled message buh"))
           expectMsg("x")
         }
       }
@@ -130,7 +130,7 @@ class LoggingReceiveSpec extends WordSpec with BeforeAndAfterEach with BeforeAnd
         val name = actor.path.toString
         actor ! PoisonPill
         expectMsgPF() {
-          case Logging.Debug(`name`, msg: String) if msg startsWith "received AutoReceiveMessage Envelope(PoisonPill" ⇒ true
+          case Logging.Debug(`name`, _, msg: String) if msg startsWith "received AutoReceiveMessage Envelope(PoisonPill" ⇒ true
         }
         awaitCond(actor.isTerminated, 100 millis)
       }
@@ -142,7 +142,7 @@ class LoggingReceiveSpec extends WordSpec with BeforeAndAfterEach with BeforeAnd
         val sys = impl.systemGuardian.path.toString
         ignoreMute(this)
         ignoreMsg {
-          case Logging.Debug(s, _) ⇒ s.contains("MainBusReaper") || s == sys
+          case Logging.Debug(`sys`, _, _) ⇒ true
         }
         system.eventStream.subscribe(testActor, classOf[Logging.Debug])
         system.eventStream.subscribe(testActor, classOf[Logging.Error])
@@ -151,51 +151,53 @@ class LoggingReceiveSpec extends WordSpec with BeforeAndAfterEach with BeforeAnd
           val lname = lifecycleGuardian.path.toString
           val supervisor = TestActorRef[TestLogActor](Props[TestLogActor].withFaultHandler(OneForOneStrategy(List(classOf[Throwable]), 5, 5000)))
           val sname = supervisor.path.toString
+          val sclass = classOf[TestLogActor]
 
           val supervisorSet = receiveWhile(messages = 2) {
-            case Logging.Debug(`lname`, msg: String) if msg startsWith "now supervising" ⇒ 1
-            case Logging.Debug(`sname`, msg: String) if msg startsWith "started"         ⇒ 2
+            case Logging.Debug(`lname`, _, msg: String) if msg startsWith "now supervising" ⇒ 1
+            case Logging.Debug(`sname`, `sclass`, msg: String) if msg startsWith "started"  ⇒ 2
           }.toSet
           expectNoMsg(Duration.Zero)
           assert(supervisorSet == Set(1, 2), supervisorSet + " was not Set(1, 2)")
 
           val actor = TestActorRef[TestLogActor](Props[TestLogActor], supervisor, "none")
           val aname = actor.path.toString
+          val aclass = classOf[TestLogActor]
 
           val set = receiveWhile(messages = 2) {
-            case Logging.Debug(`sname`, msg: String) if msg startsWith "now supervising" ⇒ 1
-            case Logging.Debug(`aname`, msg: String) if msg startsWith "started"         ⇒ 2
+            case Logging.Debug(`sname`, _, msg: String) if msg startsWith "now supervising" ⇒ 1
+            case Logging.Debug(`aname`, `aclass`, msg: String) if msg startsWith "started"  ⇒ 2
           }.toSet
           expectNoMsg(Duration.Zero)
           assert(set == Set(1, 2), set + " was not Set(1, 2)")
 
           supervisor watch actor
           expectMsgPF(hint = "now monitoring") {
-            case Logging.Debug(ref, msg: String) ⇒
+            case Logging.Debug(ref, `sclass`, msg: String) ⇒
               ref == supervisor.underlyingActor && msg.startsWith("now monitoring")
           }
 
           supervisor unwatch actor
           expectMsgPF(hint = "stopped monitoring") {
-            case Logging.Debug(ref, msg: String) ⇒
+            case Logging.Debug(ref, `sclass`, msg: String) ⇒
               ref == supervisor.underlyingActor && msg.startsWith("stopped monitoring")
           }
 
           EventFilter[ActorKilledException](occurrences = 1) intercept {
             actor ! Kill
             val set = receiveWhile(messages = 3) {
-              case Logging.Error(_: ActorKilledException, `aname`, "Kill") ⇒ 1
-              case Logging.Debug(`aname`, "restarting")                    ⇒ 2
-              case Logging.Debug(`aname`, "restarted")                     ⇒ 3
+              case Logging.Error(_: ActorKilledException, `aname`, `aclass`, "Kill") ⇒ 1
+              case Logging.Debug(`aname`, `aclass`, "restarting")                    ⇒ 2
+              case Logging.Debug(`aname`, `aclass`, "restarted")                     ⇒ 3
             }.toSet
             expectNoMsg(Duration.Zero)
             assert(set == Set(1, 2, 3), set + " was not Set(1, 2, 3)")
           }
 
           system.stop(supervisor)
-          expectMsg(Logging.Debug(sname, "stopping"))
-          expectMsg(Logging.Debug(aname, "stopped"))
-          expectMsg(Logging.Debug(sname, "stopped"))
+          expectMsg(Logging.Debug(sname, `sclass`, "stopping"))
+          expectMsg(Logging.Debug(aname, `aclass`, "stopped"))
+          expectMsg(Logging.Debug(sname, `sclass`, "stopped"))
         }
       }
     }

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

@@ -358,12 +358,12 @@ private[akka] class ActorCell(
       actor = created
       created.preStart()
       checkReceiveTimeout
-      if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, "started (" + actor + ")"))
+      if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, clazz(created), "started (" + created + ")"))
     } catch {
       // FIXME catching all and continue isn't good for OOME, ticket #1418
       case e ⇒
         try {
-          system.eventStream.publish(Error(e, self.path.toString, "error while creating actor"))
+          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)
         } finally {
@@ -373,7 +373,7 @@ private[akka] class ActorCell(
 
     def recreate(cause: Throwable): Unit = try {
       val failedActor = actor
-      if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, "restarting"))
+      if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, clazz(failedActor), "restarting"))
       val freshActor = newActor()
       if (failedActor ne null) {
         val c = currentMessage //One read only plz
@@ -388,15 +388,15 @@ private[akka] class ActorCell(
       actor = freshActor // assign it here so if preStart fails, we can null out the sef-refs next call
       hotswap = Props.noHotSwap // Reset the behavior
       freshActor.postRestart(cause)
-      if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, "restarted"))
+      if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, clazz(freshActor), "restarted"))
 
       dispatcher.resume(this) //FIXME should this be moved down?
 
       props.faultHandler.handleSupervisorRestarted(cause, self, children)
     } catch {
       // FIXME catching all and continue isn't good for OOME, ticket #1418
       case e ⇒ try {
-        system.eventStream.publish(Error(e, self.path.toString, "error while creating actor"))
+        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)
       } finally {
@@ -417,7 +417,7 @@ private[akka] class ActorCell(
       else {
         // do not process normal messages while waiting for all children to terminate
         dispatcher suspend this
-        if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, "stopping"))
+        if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, clazz(actor), "stopping"))
         // do not use stop(child) because that would dissociate the children from us, but we still want to wait for them
         for (child ← c) child.asInstanceOf[InternalActorRef].stop()
         stopping = true
@@ -428,12 +428,12 @@ private[akka] class ActorCell(
       childrenRefs.get(child.path.name) match {
         case None ⇒
           childrenRefs = childrenRefs.updated(child.path.name, ChildRestartStats(child))
-          if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, "now supervising " + child))
+          if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, clazz(actor), "now supervising " + child))
         case Some(ChildRestartStats(`child`, _, _)) ⇒
           // this is the nominal case where we created the child and entered it in actorCreated() above
-          if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, "now supervising " + child))
+          if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, clazz(actor), "now supervising " + child))
         case Some(ChildRestartStats(c, _, _)) ⇒
-          system.eventStream.publish(Warning(self.path.toString, "Already supervising other child with same name '" + child.path.name + "', old: " + c + " new: " + child))
+          system.eventStream.publish(Warning(self.path.toString, clazz(actor), "Already supervising other child with same name '" + child.path.name + "', old: " + c + " new: " + child))
       }
     }
 
@@ -448,10 +448,10 @@ private[akka] class ActorCell(
         case Recreate(cause) ⇒ recreate(cause)
         case Link(subject) ⇒
           system.deathWatch.subscribe(self, subject)
-          if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, "now monitoring " + subject))
+          if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, clazz(actor), "now monitoring " + subject))
         case Unlink(subject) ⇒
           system.deathWatch.unsubscribe(self, subject)
-          if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, "stopped monitoring " + subject))
+          if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, clazz(actor), "stopped monitoring " + subject))
         case Suspend()              ⇒ suspend()
         case Resume()               ⇒ resume()
         case Terminate()            ⇒ terminate()
@@ -460,7 +460,7 @@ private[akka] class ActorCell(
       }
     } catch {
       case e ⇒ //Should we really catch everything here?
-        system.eventStream.publish(Error(e, self.path.toString, "error while processing " + message))
+        system.eventStream.publish(Error(e, self.path.toString, clazz(actor), "error while processing " + message))
         //TODO FIXME How should problems here be handled???
         throw e
     }
@@ -480,7 +480,7 @@ private[akka] class ActorCell(
           currentMessage = null // reset current message after successful invocation
         } catch {
           case e ⇒
-            system.eventStream.publish(Error(e, self.path.toString, e.getMessage))
+            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)
@@ -500,7 +500,7 @@ private[akka] class ActorCell(
         }
       } catch {
         case e ⇒
-          system.eventStream.publish(Error(e, self.path.toString, e.getMessage))
+          system.eventStream.publish(Error(e, self.path.toString, clazz(actor), e.getMessage))
           throw e
       }
     }
@@ -530,7 +530,8 @@ private[akka] class ActorCell(
   }
 
   def autoReceiveMessage(msg: Envelope) {
-    if (system.settings.DebugAutoReceive) system.eventStream.publish(Debug(self.path.toString, "received AutoReceiveMessage " + msg))
+    if (system.settings.DebugAutoReceive)
+      system.eventStream.publish(Debug(self.path.toString, clazz(actor), "received AutoReceiveMessage " + msg))
 
     msg.message match {
       case Failed(cause)            ⇒ handleFailure(sender, cause)
@@ -554,7 +555,8 @@ private[akka] class ActorCell(
       try {
         parent.sendSystemMessage(ChildTerminated(self))
         system.deathWatch.publish(Terminated(self))
-        if (system.settings.DebugLifecycle) system.eventStream.publish(Debug(self.path.toString, "stopped"))
+        if (system.settings.DebugLifecycle)
+          system.eventStream.publish(Debug(self.path.toString, clazz(actor), "stopped")) // FIXME: can actor be null?
       } finally {
         currentMessage = null
         clearActorFields()
@@ -565,8 +567,8 @@ private[akka] class ActorCell(
 
   final def handleFailure(child: ActorRef, cause: Throwable): Unit = childrenRefs.get(child.path.name) match {
     case Some(stats) if stats.child == child ⇒ if (!props.faultHandler.handleFailure(this, child, cause, stats, childrenRefs.values)) throw cause
-    case Some(stats)                         ⇒ system.eventStream.publish(Warning(self.path.toString, "dropping Failed(" + cause + ") from unknown child " + child + " matching names but not the same, was: " + stats.child))
-    case None                                ⇒ system.eventStream.publish(Warning(self.path.toString, "dropping Failed(" + cause + ") from unknown child " + child))
+    case Some(stats)                         ⇒ system.eventStream.publish(Warning(self.path.toString, clazz(actor), "dropping Failed(" + cause + ") from unknown child " + child + " matching names but not the same, was: " + stats.child))
+    case None                                ⇒ system.eventStream.publish(Warning(self.path.toString, clazz(actor), "dropping Failed(" + cause + ") from unknown child " + child))
   }
 
   final def handleChildTerminated(child: ActorRef): Unit = {
@@ -625,4 +627,9 @@ private[akka] class ActorCell(
       lookupAndSetField(a.getClass, a, "self", self)
     }
   }
+
+  private def clazz(o: AnyRef): Class[_] = {
+    if (o eq null) this.getClass
+    else o.getClass
+  }
 }

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

@@ -330,7 +330,7 @@ class ActorSystemImpl(val name: String, applicationConfig: Config) extends Actor
   // this provides basic logging (to stdout) until .start() is called below
   val eventStream = new EventStream(DebugEventStream)
   eventStream.startStdoutLogger(settings)
-  val log = new BusLogging(eventStream, "ActorSystem") // “this” used only for .getClass in tagging messages
+  val log = new BusLogging(eventStream, "ActorSystem", this.getClass)
 
   val scheduler = createScheduler()
 

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

@@ -80,7 +80,7 @@ final case class TaskInvocation(eventStream: EventStream, runnable: Runnable, cl
       runnable.run()
     } catch {
       // FIXME catching all and continue isn't good for OOME, ticket #1418
-      case e ⇒ eventStream.publish(Error(e, "TaskInvocation", e.getMessage))
+      case e ⇒ eventStream.publish(Error(e, "TaskInvocation", this.getClass, e.getMessage))
     } finally {
       cleanup()
     }