Adjust eventLimit after getting event

Author: tedyu

core/src/main/scala/org/apache/spark/util/AsynchronousListenerBus.scala

@@ -77,6 +77,9 @@ private[spark] abstract class AsynchronousListenerBus[L <: AnyRef, E](name: Stri
           }
           val event = eventQueue.poll
           assert(event != null, "event queue was empty but the listener bus was not stopped")
+					if (eventLimit > 0) {
+            eventLimit--
+          }
           postToAll(event)
         } finally {
           self.synchronized {