Adding guards in FJDispatcher so that multiple FJDispatchers do not interact badly with one and another

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

@@ -8,6 +8,7 @@ import akka.actor.ActorRef
 import concurrent.forkjoin.{ ForkJoinWorkerThread, ForkJoinPool, ForkJoinTask }
 import java.util.concurrent._
 import java.lang.UnsupportedOperationException
+import akka.event.EventHandler
 
 /**
  * A Dispatcher that uses the ForkJoin library in scala.concurrent.forkjoin
@@ -53,8 +54,7 @@ class FJDispatcher(
 
   override private[akka] def doneProcessingMailbox(mbox: MessageQueue with ExecutableMailbox): Unit = {
     super.doneProcessingMailbox(mbox)
-    if (FJDispatcher.isCurrentThreadFJThread)
-      ForkJoinTask.helpQuiesce()
+    ForkJoinTask.helpQuiesce()
   }
 }
 
@@ -73,9 +73,13 @@ case class ForkJoinPoolConfig(targetParallelism: Int = Runtime.getRuntime.availa
           r match {
             case fjmbox: FJMailbox ⇒
               fjmbox.fjTask.reinitialize()
-              if (FJDispatcher.isCurrentThreadFJThread) fjmbox.fjTask.fork()
-              else super.execute[Unit](fjmbox.fjTask)
-            case _ ⇒ super.execute(r)
+              Thread.currentThread match {
+                case fjwt: ForkJoinWorkerThread if fjwt.getPool eq this ⇒
+                  fjmbox.fjTask.fork() //We should do fjwt.pushTask(fjmbox.fjTask) but it's package protected
+                case _ ⇒ super.execute[Unit](fjmbox.fjTask)
+              }
+            case _ ⇒
+              super.execute(r)
           }
         }
 
@@ -100,7 +104,7 @@ trait FJMailbox { self: ExecutableMailbox ⇒
     def getRawResult() = result
     def setRawResult(v: Unit) { result = v }
     def exec() = {
-      self.run()
+      try { self.run() } catch { case t ⇒ EventHandler.error(t, self, "Exception in FJ Worker") }
       true
     }
     def run() { invoke() }