Merge remote-tracking branch 'origin/master' into wip-1581-patterns-ask

akka-actor/src/main/scala/akka/pattern/Patterns.scala

@@ -4,10 +4,10 @@
 package akka.pattern
 
 object Patterns {
-  import akka.actor.ActorRef
+  import akka.actor.{ ActorRef, ActorSystem }
   import akka.dispatch.Future
   import akka.pattern.{ ask ⇒ scalaAsk }
-  import akka.util.Timeout
+  import akka.util.{ Timeout, Duration }
 
   /**
    * <i>Java API for `akka.pattern.ask`:</i>
@@ -121,4 +121,18 @@ object Patterns {
    * [see [[akka.dispatch.Future]] for a description of `flow`]
    */
   def pipeTo[T](future: Future[T], actorRef: ActorRef): Future[T] = akka.pattern.pipeTo(future, actorRef)
+
+  /**
+   * Returns a [[akka.dispatch.Future]] that will be completed with success (value `true`) when
+   * existing messages of the target actor has been processed and the actor has been
+   * terminated.
+   *
+   * Useful when you need to wait for termination or compose ordered termination of several actors.
+   *
+   * If the target actor isn't terminated within the timeout the [[akka.dispatch.Future]]
+   * is completed with failure [[akka.actor.ActorTimeoutException]].
+   */
+  def gracefulStop(target: ActorRef, timeout: Duration, system: ActorSystem): Future[java.lang.Boolean] = {
+    akka.pattern.gracefulStop(target, timeout)(system).asInstanceOf[Future[java.lang.Boolean]]
+  }
 }