Merge pull request #15758 from akka/wip-15757-refactor-actorsystem-termination-√

Wip 15757 refactor actorsystem termination √

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

@@ -195,7 +195,7 @@ class ActorSystemSpec extends AkkaSpec(ActorSystemSpec.config) with ImplicitSend
         }
       }
 
-      system2.shutdown()
+      system2.terminate()
       Await.ready(latch, 5 seconds)
 
       val expected = (for (i ← 1 to count) yield i).reverse
@@ -213,28 +213,36 @@ class ActorSystemSpec extends AkkaSpec(ActorSystemSpec.config) with ImplicitSend
         callbackWasRun = true
       }
       import system.dispatcher
-      system2.scheduler.scheduleOnce(200.millis.dilated) { system2.shutdown() }
+      system2.scheduler.scheduleOnce(200.millis.dilated) { system2.terminate() }
 
       system2.awaitTermination(5 seconds)
+      Await.ready(system2.whenTerminated, 5 seconds)
       callbackWasRun should be(true)
     }
 
     "return isTerminated status correctly" in {
-      val system = ActorSystem()
+      val system = ActorSystem().asInstanceOf[ActorSystemImpl]
       system.isTerminated should be(false)
-      system.shutdown()
+      val wt = system.whenTerminated
+      wt.isCompleted should be(false)
+      val f = system.terminate()
+      val terminated = Await.result(wt, 10 seconds)
+      terminated.actor should be(system.provider.rootGuardian)
+      terminated.addressTerminated should be(true)
+      terminated.existenceConfirmed should be(true)
+      terminated should be theSameInstanceAs Await.result(f, 10 seconds)
       system.awaitTermination(10 seconds)
       system.isTerminated should be(true)
     }
 
     "throw RejectedExecutionException when shutdown" in {
       val system2 = ActorSystem("AwaitTermination", AkkaSpec.testConf)
-      system2.shutdown()
+      Await.ready(system2.terminate(), 10 seconds)
       system2.awaitTermination(10 seconds)
 
       intercept[RejectedExecutionException] {
         system2.registerOnTermination { println("IF YOU SEE THIS THEN THERE'S A BUG HERE") }
-      }.getMessage should be("Must be called prior to system shutdown.")
+      }.getMessage should be("ActorSystem already terminated.")
     }
 
     "reliably create waves of actors" in {
@@ -252,10 +260,10 @@ class ActorSystemSpec extends AkkaSpec(ActorSystemSpec.config) with ImplicitSend
     "reliable deny creation of actors while shutting down" in {
       val system = ActorSystem()
       import system.dispatcher
-      system.scheduler.scheduleOnce(200 millis) { system.shutdown() }
+      system.scheduler.scheduleOnce(200 millis) { system.terminate() }
       var failing = false
       var created = Vector.empty[ActorRef]
-      while (!system.isTerminated) {
+      while (!system.whenTerminated.isCompleted) {
         try {
           val t = system.actorOf(Props[ActorSystemSpec.Terminater])
           failing should not be true // because once failing => always failing (it’s due to shutdown)
@@ -278,7 +286,7 @@ class ActorSystemSpec extends AkkaSpec(ActorSystemSpec.config) with ImplicitSend
       implicit val system = ActorSystem("Stop", AkkaSpec.testConf)
       EventFilter[ActorKilledException]() intercept {
         system.actorSelection("/user") ! Kill
-        awaitCond(system.isTerminated)
+        Await.ready(system.whenTerminated, Duration.Inf)
       }
     }
 
@@ -313,7 +321,7 @@ class ActorSystemSpec extends AkkaSpec(ActorSystemSpec.config) with ImplicitSend
       }))
       EventFilter[Exception]("hello") intercept {
         a ! "die"
-        awaitCond(system.isTerminated)
+        Await.ready(system.whenTerminated, Duration.Inf)
       }
     }
 

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

@@ -111,7 +111,7 @@ object Chameneos {
     val actor = system.actorOf(Props(new Mall(1000000, 4)))
     Thread.sleep(10000)
     println("Elapsed: " + (end - start))
-    system.shutdown()
+    system.terminate()
   }
 
   def main(args: Array[String]): Unit = run()

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

@@ -33,7 +33,7 @@ object Main {
         val app = system.actorOf(Props(appClass), "app")
         val terminator = system.actorOf(Props(classOf[Terminator], app), "app-terminator")
       } catch {
-        case NonFatal(e) ⇒ system.shutdown(); throw e
+        case NonFatal(e) ⇒ system.terminate(); throw e
       }
     }
   }
@@ -43,7 +43,7 @@ object Main {
     def receive = {
       case Terminated(_) ⇒
         log.info("application supervisor has terminated, shutting down")
-        context.system.shutdown()
+        context.system.terminate()
     }
   }
 

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

@@ -156,7 +156,7 @@ trait ActorRefProvider {
    * This Future is completed upon termination of this ActorRefProvider, which
    * is usually initiated by stopping the guardian via ActorSystem.stop().
    */
-  def terminationFuture: Future[Unit]
+  def terminationFuture: Future[Terminated]
 
   /**
    * Obtain the address which is to be used within sender references when
@@ -463,45 +463,53 @@ private[akka] class LocalActorRefProvider private[akka] (
   override val deadLetters: InternalActorRef =
     _deadLetters.getOrElse((p: ActorPath) ⇒ new DeadLetterActorRef(this, p, eventStream)).apply(rootPath / "deadLetters")
 
+  private[this] final val terminationPromise: Promise[Terminated] = Promise[Terminated]()
+
+  def terminationFuture: Future[Terminated] = terminationPromise.future
+
   /*
    * generate name for temporary actor refs
    */
   private val tempNumber = new AtomicLong
 
-  private def tempName() = Helpers.base64(tempNumber.getAndIncrement())
-
   private val tempNode = rootPath / "temp"
 
-  override def tempPath(): ActorPath = tempNode / tempName()
+  override def tempPath(): ActorPath = tempNode / Helpers.base64(tempNumber.getAndIncrement())
 
   /**
    * Top-level anchor for the supervision hierarchy of this actor system. Will
    * receive only Supervise/ChildTerminated system messages or Failure message.
    */
   private[akka] val theOneWhoWalksTheBubblesOfSpaceTime: InternalActorRef = new MinimalActorRef {
-    val stopped = new Switch(false)
+    val causeOfTermination: Promise[Terminated] = Promise[Terminated]()
-
-    @volatile
-    var causeOfTermination: Option[Throwable] = None
 
     val path = rootPath / "bubble-walker"
 
     def provider: ActorRefProvider = LocalActorRefProvider.this
 
-    override def stop(): Unit = stopped switchOn { terminationPromise.complete(causeOfTermination.map(Failure(_)).getOrElse(Success(()))) }
+    def isWalking = causeOfTermination.future.isCompleted == false
-    @deprecated("Use context.watch(actor) and receive Terminated(actor)", "2.2") override def isTerminated: Boolean = stopped.isOn
 
-    override def !(message: Any)(implicit sender: ActorRef = Actor.noSender): Unit = stopped.ifOff(message match {
+    override def stop(): Unit = {
-      case null ⇒ throw new InvalidMessageException("Message is null")
+      causeOfTermination.trySuccess(Terminated(provider.rootGuardian)(existenceConfirmed = true, addressTerminated = true)) //Idempotent
-      case _    ⇒ log.error(s"$this received unexpected message [$message]")
+      terminationPromise.tryCompleteWith(causeOfTermination.future) // Signal termination downstream, idempotent
-    })
+    }
 
-    override def sendSystemMessage(message: SystemMessage): Unit = stopped ifOff {
+    @deprecated("Use context.watch(actor) and receive Terminated(actor)", "2.2")
+    override def isTerminated: Boolean = !isWalking
+
+    override def !(message: Any)(implicit sender: ActorRef = Actor.noSender): Unit =
+      if (isWalking)
+        message match {
+          case null ⇒ throw new InvalidMessageException("Message is null")
+          case _    ⇒ log.error(s"$this received unexpected message [$message]")
+        }
+
+    override def sendSystemMessage(message: SystemMessage): Unit = if (isWalking) {
       message match {
-        case Failed(child, ex, _) ⇒
+        case Failed(child: InternalActorRef, ex, _) ⇒
           log.error(ex, s"guardian $child failed, shutting down!")
-          causeOfTermination = Some(ex)
+          causeOfTermination.tryFailure(ex)
-          child.asInstanceOf[InternalActorRef].stop()
+          child.stop()
         case Supervise(_, _)           ⇒ // TODO register child in some map to keep track of it and enable shutdown after all dead
         case _: DeathWatchNotification ⇒ stop()
         case _                         ⇒ log.error(s"$this received unexpected system message [$message]")
@@ -519,10 +527,6 @@ private[akka] class LocalActorRefProvider private[akka] (
   @volatile
   private var system: ActorSystemImpl = _
 
-  lazy val terminationPromise: Promise[Unit] = Promise[Unit]()
-
-  def terminationFuture: Future[Unit] = terminationPromise.future
-
   @volatile
   private var extraNames: Map[String, InternalActorRef] = Map()
 

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

@@ -6,6 +6,7 @@ package akka.actor
 
 import java.io.Closeable
 import java.util.concurrent.{ ConcurrentHashMap, ThreadFactory, CountDownLatch, TimeoutException, RejectedExecutionException }
+import java.util.concurrent.atomic.{ AtomicReference }
 import java.util.concurrent.TimeUnit.MILLISECONDS
 import com.typesafe.config.{ Config, ConfigFactory }
 import akka.event._
@@ -17,7 +18,7 @@ import akka.util._
 import scala.annotation.tailrec
 import scala.collection.immutable
 import scala.concurrent.duration.{ FiniteDuration, Duration }
-import scala.concurrent.{ Await, Awaitable, CanAwait, Future, ExecutionContext, ExecutionContextExecutor }
+import scala.concurrent.{ Await, Future, Promise, ExecutionContext, ExecutionContextExecutor }
 import scala.util.{ Failure, Success, Try }
 import scala.util.control.{ NonFatal, ControlThrowable }
 
@@ -391,12 +392,14 @@ abstract class ActorSystem extends ActorRefFactory {
    *
    * @throws TimeoutException in case of timeout
    */
+  @deprecated("Use Await.result(whenTerminated, timeout) instead", "2.4")
   def awaitTermination(timeout: Duration): Unit
 
   /**
    * Block current thread until the system has been shutdown. This will
    * block until after all on termination callbacks have been run.
    */
+  @deprecated("Use Await.result(whenTerminated, Duration.Inf) instead", "2.4")
   def awaitTermination(): Unit
 
   /**
@@ -405,6 +408,7 @@ abstract class ActorSystem extends ActorRefFactory {
    * (below which the logging actors reside) and the execute all registered
    * termination handlers (see [[ActorSystem.registerOnTermination]]).
    */
+  @deprecated("Use the terminate() method instead", "2.4")
   def shutdown(): Unit
 
   /**
@@ -414,8 +418,23 @@ abstract class ActorSystem extends ActorRefFactory {
    * returns `false`, the status is actually unknown, since it might have
    * changed since you queried it.
    */
+  @deprecated("Use the whenTerminated method instead.", "2.4")
   def isTerminated: Boolean
 
+  /**
+   * Terminates this actor system. This will stop the guardian actor, which in turn
+   * will recursively stop all its child actors, then the system guardian
+   * (below which the logging actors reside) and the execute all registered
+   * termination handlers (see [[ActorSystem.registerOnTermination]]).
+   */
+  def terminate(): Future[Terminated]
+
+  /**
+   * Returns a Future which will be completed after the ActorSystem has been terminated
+   * and termination hooks have been executed.
+   */
+  def whenTerminated: Future[Terminated]
+
   /**
    * Registers the provided extension and creates its payload, if this extension isn't already registered
    * This method has putIfAbsent-semantics, this method can potentially block, waiting for the initialization
@@ -533,7 +552,7 @@ private[akka] class ActorSystemImpl(val name: String, applicationConfig: Config,
               }
             } else {
               log.error(cause, "Uncaught fatal error from thread [{}] shutting down ActorSystem [{}]", thread.getName, name)
-              shutdown()
+              terminate()
             }
         }
       }
@@ -618,7 +637,9 @@ private[akka] class ActorSystemImpl(val name: String, applicationConfig: Config,
         override def reportFailure(t: Throwable): Unit = dispatcher reportFailure t
       })
 
-  def terminationFuture: Future[Unit] = provider.terminationFuture
+  private[this] final val terminationCallbacks = new TerminationCallbacks(provider.terminationFuture)(dispatcher)
+
+  override def whenTerminated: Future[Terminated] = terminationCallbacks.terminationFuture
   def lookupRoot: InternalActorRef = provider.rootGuardian
   def guardian: LocalActorRef = provider.guardian
   def systemGuardian: LocalActorRef = provider.systemGuardian
@@ -638,29 +659,23 @@ private[akka] class ActorSystemImpl(val name: String, applicationConfig: Config,
     this
   } catch {
     case NonFatal(e) ⇒
-      try {
+      try terminate() catch { case NonFatal(_) ⇒ Try(stopScheduler()) }
-        shutdown()
-      } catch { case NonFatal(_) ⇒ Try(stopScheduler()) }
       throw e
   }
 
   def start(): this.type = _start
-
-  private lazy val terminationCallbacks = {
-    implicit val d = dispatcher
-    val callbacks = new TerminationCallbacks
-    terminationFuture onComplete (_ ⇒ callbacks.run)
-    callbacks
-  }
   def registerOnTermination[T](code: ⇒ T) { registerOnTermination(new Runnable { def run = code }) }
   def registerOnTermination(code: Runnable) { terminationCallbacks.add(code) }
-  def awaitTermination(timeout: Duration) { Await.ready(terminationCallbacks, timeout) }
+  override def awaitTermination(timeout: Duration) { Await.ready(whenTerminated, timeout) }
-  def awaitTermination() = awaitTermination(Duration.Inf)
+  override def awaitTermination() = awaitTermination(Duration.Inf)
-  def isTerminated = terminationCallbacks.isTerminated
+  override def isTerminated = whenTerminated.isCompleted
 
-  def shutdown(): Unit = {
+  override def shutdown(): Unit = terminate()
+
+  override def terminate(): Future[Terminated] = {
     if (!settings.LogDeadLettersDuringShutdown) logDeadLetterListener foreach stop
     guardian.stop()
+    whenTerminated
   }
 
   @volatile var aborting = false
@@ -673,7 +688,7 @@ private[akka] class ActorSystemImpl(val name: String, applicationConfig: Config,
    */
   def abort(): Unit = {
     aborting = true
-    shutdown()
+    terminate()
   }
 
   //#create-scheduler
@@ -798,44 +813,31 @@ private[akka] class ActorSystemImpl(val name: String, applicationConfig: Config,
     printNode(lookupRoot, "")
   }
 
-  final class TerminationCallbacks extends Runnable with Awaitable[Unit] {
+  final class TerminationCallbacks[T](upStreamTerminated: Future[T])(implicit ec: ExecutionContext) {
-    private val lock = new ReentrantGuard
+    private[this] final val done = Promise[T]()
-    private var callbacks: List[Runnable] = _ //non-volatile since guarded by the lock
+    private[this] final val ref = new AtomicReference(done)
-    lock withGuard { callbacks = Nil }
 
-    private val latch = new CountDownLatch(1)
+    // onComplete never fires twice so safe to avoid nullcheck
+    upStreamTerminated onComplete { t ⇒ ref.getAndSet(null).complete(t) }
 
-    final def add(callback: Runnable): Unit = {
+    /**
-      latch.getCount match {
+     * Adds a Runnable that will be executed on ActorSystem termination.
-        case 0 ⇒ throw new RejectedExecutionException("Must be called prior to system shutdown.")
+     * Note that callbacks are executed in reverse order of insertion.
-        case _ ⇒ lock withGuard {
+     * @param r The callback to be executed on ActorSystem termination
-          if (latch.getCount == 0) throw new RejectedExecutionException("Must be called prior to system shutdown.")
+     * @throws RejectedExecutionException if called after ActorSystem has been terminated
-          else callbacks ::= callback
+     */
-        }
+    final def add(r: Runnable): Unit = {
+      @tailrec def addRec(r: Runnable, p: Promise[T]): Unit = ref.get match {
+        case null                               ⇒ throw new RejectedExecutionException("ActorSystem already terminated.")
+        case some if ref.compareAndSet(some, p) ⇒ some.completeWith(p.future.andThen { case _ ⇒ r.run() })
+        case _                                  ⇒ addRec(r, p)
       }
+      addRec(r, Promise[T]())
     }
 
-    final def run(): Unit = lock withGuard {
+    /**
-      @tailrec def runNext(c: List[Runnable]): List[Runnable] = c match {
+     * Returns a Future which will be completed once all registered callbacks have been executed.
-        case Nil ⇒ Nil
+     */
-        case callback :: rest ⇒
+    def terminationFuture: Future[T] = done.future
-          try callback.run() catch { case NonFatal(e) ⇒ log.error(e, "Failed to run termination callback, due to [{}]", e.getMessage) }
-          runNext(rest)
-      }
-      try { callbacks = runNext(callbacks) } finally latch.countDown()
-    }
-
-    final def ready(atMost: Duration)(implicit permit: CanAwait): this.type = {
-      if (atMost.isFinite()) {
-        if (!latch.await(atMost.length, atMost.unit))
-          throw new TimeoutException("Await termination timed out after [%s]" format (atMost.toString))
-      } else latch.await()
-
-      this
-    }
-
-    final def result(atMost: Duration)(implicit permit: CanAwait): Unit = ready(atMost)
-
-    final def isTerminated: Boolean = latch.getCount == 0
   }
 }

akka-cluster/src/multi-jvm/scala/akka/cluster/ClusterDeathWatchSpec.scala

@@ -4,6 +4,7 @@
 package akka.cluster
 
 import language.postfixOps
+import scala.concurrent.Await
 import scala.concurrent.duration._
 import com.typesafe.config.ConfigFactory
 import org.scalatest.BeforeAndAfter
@@ -237,7 +238,7 @@ abstract class ClusterDeathWatchSpec
         enterBarrier("first-unavailable")
 
         val timeout = remainingOrDefault
-        try system.awaitTermination(timeout) catch {
+        try Await.ready(system.whenTerminated, timeout) catch {
           case _: TimeoutException ⇒
             fail("Failed to stop [%s] within [%s] \n%s".format(system.name, timeout,
               system.asInstanceOf[ActorSystemImpl].printTree))

akka-cluster/src/multi-jvm/scala/akka/cluster/RestartFirstSeedNodeSpec.scala

@@ -53,10 +53,8 @@ abstract class RestartFirstSeedNodeSpec
 
   override def afterAll(): Unit = {
     runOn(seed1) {
-      if (seed1System.isTerminated)
+      shutdown(
-        shutdown(restartedSeed1System)
+        if (seed1System.whenTerminated.isCompleted) restartedSeed1System else seed1System)
-      else
-        shutdown(seed1System)
     }
     super.afterAll()
   }

akka-cluster/src/multi-jvm/scala/akka/cluster/UnreachableNodeJoinsAgainSpec.scala

@@ -5,6 +5,7 @@ package akka.cluster
 
 import language.postfixOps
 import scala.collection.immutable
+import scala.concurrent.Await
 import scala.concurrent.duration._
 import com.typesafe.config.ConfigFactory
 import akka.actor.ActorSystem
@@ -159,7 +160,7 @@ abstract class UnreachableNodeJoinsAgainSpec
 
       runOn(victim) {
         val victimAddress = system.asInstanceOf[ExtendedActorSystem].provider.getDefaultAddress
-        system.awaitTermination(10 seconds)
+        Await.ready(system.whenTerminated, 10 seconds)
         // create new ActorSystem with same host:port
         val freshSystem = ActorSystem(system.name, ConfigFactory.parseString(s"""
             akka.remote.netty.tcp {

akka-contrib/src/test/scala/akka/contrib/mailbox/PeekMailboxSpec.scala

@@ -108,7 +108,7 @@ class MyActor extends Actor {
   }
 
   override def postStop() {
-    context.system.shutdown()
+    context.system.terminate()
   }
   //#business-logic-elided
 }

akka-contrib/src/test/scala/akka/contrib/pattern/ClusterSingletonProxySpec.scala

@@ -26,7 +26,7 @@ class ClusterSingletonProxySpec extends WordSpecLike with Matchers with BeforeAn
     }
   }
 
-  override def afterAll() = testSystems.foreach(_.system.shutdown())
+  override def afterAll() = testSystems.foreach(_.system.terminate())
 }
 
 object ClusterSingletonProxySpec {

akka-docs/rst/java/code/docs/actor/japi/FaultHandlingDocSample.java

@@ -22,7 +22,6 @@ import com.typesafe.config.ConfigFactory;
 
 import static akka.japi.Util.classTag;
 
-import static akka.actor.SupervisorStrategy.resume;
 import static akka.actor.SupervisorStrategy.restart;
 import static akka.actor.SupervisorStrategy.stop;
 import static akka.actor.SupervisorStrategy.escalate;
@@ -76,12 +75,12 @@ public class FaultHandlingDocSample {
         log.info("Current progress: {} %", progress.percent);
         if (progress.percent >= 100.0) {
           log.info("That's all, shutting down");
-          getContext().system().shutdown();
+          getContext().system().terminate();
         }
       } else if (msg == ReceiveTimeout.getInstance()) {
         // No progress within 15 seconds, ServiceUnavailable
         log.error("Shutting down due to unavailable service");
-        getContext().system().shutdown();
+        getContext().system().terminate();
       } else {
         unhandled(msg);
       }

akka-docs/rst/java/code/docs/io/japi/EchoServer.java

@@ -28,7 +28,7 @@ public class EchoServer {
       watcher.tell(ackServer, ActorRef.noSender());
       latch.await(10, TimeUnit.MINUTES);
     } finally {
-      system.shutdown();
+      system.terminate();
     }
   }
 

akka-docs/rst/java/lambda-actors.rst

@@ -678,7 +678,7 @@ actors does not respond (i.e. processing a message for extended periods of time
 and therefore not receiving the stop command), this whole process will be
 stuck.
 
-Upon :meth:`ActorSystem.shutdown()`, the system guardian actors will be
+Upon :meth:`ActorSystem.terminate()`, the system guardian actors will be
 stopped, and the aforementioned process will ensure proper termination of the
 whole system.
 

akka-docs/rst/java/untyped-actors.rst

@@ -621,7 +621,7 @@ actors does not respond (i.e. processing a message for extended periods of time
 and therefore not receiving the stop command), this whole process will be
 stuck.
 
-Upon :meth:`ActorSystem.shutdown()`, the system guardian actors will be
+Upon :meth:`ActorSystem.terminate()`, the system guardian actors will be
 stopped, and the aforementioned process will ensure proper termination of the
 whole system.
 

akka-docs/rst/scala/actors.rst

@@ -672,7 +672,7 @@ actors does not respond (i.e. processing a message for extended periods of time
 and therefore not receiving the stop command), this whole process will be
 stuck.
 
-Upon :meth:`ActorSystem.shutdown()`, the system guardian actors will be
+Upon :meth:`ActorSystem.terminate()`, the system guardian actors will be
 stopped, and the aforementioned process will ensure proper termination of the
 whole system.
 

akka-docs/rst/scala/code/docs/actor/FaultHandlingDocSample.scala

@@ -53,13 +53,13 @@ class Listener extends Actor with ActorLogging {
       log.info("Current progress: {} %", percent)
       if (percent >= 100.0) {
         log.info("That's all, shutting down")
-        context.system.shutdown()
+        context.system.terminate()
       }
 
     case ReceiveTimeout =>
       // No progress within 15 seconds, ServiceUnavailable
       log.error("Shutting down due to unavailable service")
-      context.system.shutdown()
+      context.system.terminate()
   }
 }
 

akka-docs/rst/scala/code/docs/io/EchoServer.scala

@@ -22,7 +22,7 @@ object EchoServer extends App {
 
   // make sure to stop the system so that the application stops
   try run()
-  finally system.shutdown()
+  finally system.terminate()
 
   def run(): Unit = {
     import ActorDSL._

akka-docs/rst/scala/code/docs/io/ReadBackPressure.scala

@@ -10,6 +10,9 @@ import java.net.InetSocketAddress
 import akka.testkit.{ ImplicitSender, TestProbe, AkkaSpec }
 import akka.util.ByteString
 
+import scala.concurrent.Await
+import scala.concurrent.duration.Duration
+
 object PullReadingExample {
 
   class Listener(monitor: ActorRef) extends Actor {
@@ -77,7 +80,6 @@ class PullReadingSpec extends AkkaSpec with ImplicitSender {
     client.send(connection, ResumeReading)
     client.expectMsg(Received(ByteString("hello")))
 
-    system.shutdown()
+    Await.ready(system.terminate(), Duration.Inf)
-    system.awaitTermination
   }
 }

akka-docs/rst/scala/code/docs/persistence/PersistenceDocSpec.scala

@@ -322,7 +322,7 @@ trait PersistenceDocSpec {
 
     processor ! PersistentBatch(List(Persistent("a"), Persistent("b")))
     //#batch-write
-    system.shutdown()
+    system.terminate()
   }
 
   new AnyRef {

akka-docs/rst/scala/code/docs/testkit/TestkitDocSpec.scala

@@ -284,7 +284,7 @@ class TestkitDocSpec extends AkkaSpec with DefaultTimeout with ImplicitSender {
       //#put-your-test-code-here
       val probe = TestProbe()
       probe.send(testActor, "hello")
-      try expectMsg("hello") catch { case NonFatal(e) => system.shutdown(); throw e }
+      try expectMsg("hello") catch { case NonFatal(e) => system.terminate(); throw e }
       //#put-your-test-code-here
 
       shutdown(system)

akka-kernel/src/main/scala/akka/kernel/Main.scala

@@ -29,7 +29,7 @@ import scala.collection.JavaConverters._
  *   }
  *
  *   def shutdown = {
- *     system.shutdown()
+ *     system.terminate()
  *   }
  * }
  * }}}

akka-multi-node-testkit/src/main/scala/akka/remote/testconductor/Player.scala

@@ -31,9 +31,11 @@ trait Player { this: TestConductorExt ⇒
 
   private var _client: ActorRef = _
   private def client = _client match {
-    case null                     ⇒ throw new IllegalStateException("TestConductor client not yet started")
+    case null ⇒
-    case _ if system.isTerminated ⇒ throw new IllegalStateException("TestConductor unavailable because system is shutdown; you need to startNewSystem() before this point")
+      throw new IllegalStateException("TestConductor client not yet started")
-    case x                        ⇒ x
+    case _ if system.whenTerminated.isCompleted ⇒
+      throw new IllegalStateException("TestConductor unavailable because system is terminated; you need to startNewSystem() before this point")
+    case x ⇒ x
   }
 
   /**
@@ -241,7 +243,7 @@ private[akka] class ClientFSM(name: RoleName, controllerAddr: InetSocketAddress)
           // FIXME: Currently ignoring, needs support from Remoting
           stay
         case TerminateMsg(Left(false)) ⇒
-          context.system.shutdown()
+          context.system.terminate()
           stay
         case TerminateMsg(Left(true)) ⇒
           context.system.asInstanceOf[ActorSystemImpl].abort()

akka-osgi/src/main/scala/akka/osgi/ActorSystemActivator.scala

@@ -82,7 +82,7 @@ abstract class ActorSystemActivator extends BundleActivator {
    */
   def stop(context: BundleContext): Unit = {
     registration foreach (_.unregister())
-    system foreach (_.shutdown())
+    system foreach (_.terminate())
   }
 
   /**

akka-osgi/src/test/scala/akka/osgi/ActorSystemActivatorTest.scala

@@ -51,11 +51,11 @@ class PingPongActorSystemActivatorTest extends WordSpec with Matchers with PojoS
     "stop the ActorSystem when bundle stops" in {
       filterErrors() {
         val system = serviceForType[ActorSystem]
-        system.isTerminated should be(false)
+        system.whenTerminated.isCompleted should be(false)
 
         bundleForName(TEST_BUNDLE_NAME).stop()
-        system.awaitTermination()
+        Await.ready(system.whenTerminated, Duration.Inf)
-        system.isTerminated should be(true)
+        system.whenTerminated.isCompleted should be(true)
       }
     }
   }

akka-persistence/src/test/scala/akka/persistence/serialization/SerializerSpec.scala

@@ -13,6 +13,8 @@ import akka.testkit._
 
 import akka.persistence.AtLeastOnceDelivery.AtLeastOnceDeliverySnapshot
 import akka.persistence.AtLeastOnceDelivery.UnconfirmedDelivery
+import scala.concurrent.Await
+import scala.concurrent.duration.Duration
 
 object SerializerSpecConfigs {
   val customSerializers = ConfigFactory.parseString(
@@ -202,8 +204,7 @@ class MessageSerializerRemotingSpec extends AkkaSpec(remote.withFallback(customS
   }
 
   override def afterTermination() {
-    remoteSystem.shutdown()
+    Await.ready(remoteSystem.terminate(), Duration.Inf)
-    remoteSystem.awaitTermination()
   }
 
   "A message serializer" must {

akka-remote-tests/src/multi-jvm/scala/akka/remote/RemoteDeploymentDeathWatchSpec.scala

@@ -5,6 +5,7 @@ package akka.remote
 
 import language.postfixOps
 import java.util.concurrent.TimeoutException
+import scala.concurrent.Await
 import scala.concurrent.duration._
 import com.typesafe.config.ConfigFactory
 import akka.actor.Actor
@@ -76,8 +77,9 @@ abstract class RemoteDeploymentDeathWatchSpec
 
         sleep()
         // if the remote deployed actor is not removed the system will not shutdown
+
         val timeout = remainingOrDefault
-        try system.awaitTermination(timeout) catch {
+        try Await.ready(system.whenTerminated, timeout) catch {
           case _: TimeoutException ⇒
             fail("Failed to stop [%s] within [%s] \n%s".format(system.name, timeout,
               system.asInstanceOf[ActorSystemImpl].printTree))

akka-remote-tests/src/multi-jvm/scala/akka/remote/RemoteNodeRestartDeathWatchSpec.scala

@@ -4,6 +4,7 @@
 package akka.remote
 
 import language.postfixOps
+import scala.concurrent.Await
 import scala.concurrent.duration._
 import com.typesafe.config.ConfigFactory
 import akka.actor.Actor
@@ -40,7 +41,7 @@ object RemoteNodeRestartDeathWatchMultiJvmSpec extends MultiNodeConfig {
     def receive = {
       case "shutdown" ⇒
         sender() ! "shutdown-ack"
-        context.system.shutdown()
+        context.system.terminate()
       case msg ⇒ sender() ! msg
     }
   }
@@ -100,7 +101,7 @@ abstract class RemoteNodeRestartDeathWatchSpec
 
         enterBarrier("watch-established")
 
-        system.awaitTermination(30.seconds)
+        Await.ready(system.whenTerminated, 30.seconds)
 
         val freshSystem = ActorSystem(system.name, ConfigFactory.parseString(s"""
                     akka.remote.netty.tcp {
@@ -110,7 +111,7 @@ abstract class RemoteNodeRestartDeathWatchSpec
                     """).withFallback(system.settings.config))
         freshSystem.actorOf(Props[Subject], "subject")
 
-        freshSystem.awaitTermination(30.seconds)
+        Await.ready(freshSystem.whenTerminated, 30.seconds)
       }
 
     }

akka-remote-tests/src/multi-jvm/scala/akka/remote/RemoteNodeShutdownAndComesBackSpec.scala

@@ -37,7 +37,7 @@ object RemoteNodeShutdownAndComesBackSpec extends MultiNodeConfig {
 
   class Subject extends Actor {
     def receive = {
-      case "shutdown" ⇒ context.system.shutdown()
+      case "shutdown" ⇒ context.system.terminate()
       case msg        ⇒ sender() ! msg
     }
   }
@@ -133,7 +133,7 @@ abstract class RemoteNodeShutdownAndComesBackSpec
 
         enterBarrier("watch-established")
 
-        system.awaitTermination(30.seconds)
+        Await.ready(system.whenTerminated, 30.seconds)
 
         val freshSystem = ActorSystem(system.name, ConfigFactory.parseString(s"""
                     akka.remote.netty.tcp {
@@ -143,7 +143,7 @@ abstract class RemoteNodeShutdownAndComesBackSpec
                     """).withFallback(system.settings.config))
         freshSystem.actorOf(Props[Subject], "subject")
 
-        freshSystem.awaitTermination(30.seconds)
+        Await.ready(freshSystem.whenTerminated, 30.seconds)
       }
 
     }

akka-remote-tests/src/multi-jvm/scala/akka/remote/RemoteQuarantinePiercingSpec.scala

@@ -32,8 +32,8 @@ object RemoteQuarantinePiercingSpec extends MultiNodeConfig {
 
   class Subject extends Actor {
     def receive = {
-      case "shutdown" ⇒ context.system.shutdown()
+      case "shutdown" ⇒ context.system.terminate()
-      case "identify" ⇒ sender() ! (AddressUidExtension(context.system).addressUid, self)
+      case "identify" ⇒ sender() ! (AddressUidExtension(context.system).addressUid -> self)
     }
   }
 
@@ -100,7 +100,7 @@ abstract class RemoteQuarantinePiercingSpec extends MultiNodeSpec(RemoteQuaranti
 
         enterBarrier("actor-identified")
 
-        system.awaitTermination(30.seconds)
+        Await.ready(system.whenTerminated, 30.seconds)
 
         val freshSystem = ActorSystem(system.name, ConfigFactory.parseString(s"""
                     akka.remote.netty.tcp {
@@ -110,7 +110,7 @@ abstract class RemoteQuarantinePiercingSpec extends MultiNodeSpec(RemoteQuaranti
                     """).withFallback(system.settings.config))
         freshSystem.actorOf(Props[Subject], "subject")
 
-        freshSystem.awaitTermination(30.seconds)
+        Await.ready(freshSystem.whenTerminated, 30.seconds)
       }
 
     }

akka-remote-tests/src/multi-jvm/scala/akka/remote/RemoteReDeploymentSpec.scala

@@ -10,6 +10,7 @@ import akka.actor.Props
 import akka.remote.transport.ThrottlerTransportAdapter.Direction._
 import com.typesafe.config.ConfigFactory
 import akka.actor.ActorSystem
+import scala.concurrent.Await
 import scala.concurrent.duration._
 import akka.actor.ActorLogging
 import akka.remote.testconductor.TestConductor
@@ -124,7 +125,7 @@ abstract class RemoteReDeploymentMultiJvmSpec extends MultiNodeSpec(RemoteReDepl
       var sys: ActorSystem = null
 
       runOn(second) {
-        system.awaitTermination(30.seconds)
+        Await.ready(system.whenTerminated, 30.seconds)
         expectNoMsg(sleepAfterKill)
         sys = startNewSystem()
       }

akka-remote/src/main/scala/akka/remote/RemoteActorRefProvider.scala

@@ -135,7 +135,7 @@ private[akka] class RemoteActorRefProvider(
   override def rootGuardian: InternalActorRef = local.rootGuardian
   override def guardian: LocalActorRef = local.guardian
   override def systemGuardian: LocalActorRef = local.systemGuardian
-  override def terminationFuture: Future[Unit] = local.terminationFuture
+  override def terminationFuture: Future[Terminated] = local.terminationFuture
   override def registerTempActor(actorRef: InternalActorRef, path: ActorPath): Unit = local.registerTempActor(actorRef, path)
   override def unregisterTempActor(path: ActorPath): Unit = local.unregisterTempActor(path)
   override def tempPath(): ActorPath = local.tempPath()

akka-samples/akka-docs-java-lambda/src/test/java/docs/actor/ActorDocTest.java

@@ -5,8 +5,6 @@
 package docs.actor;
 
 import akka.actor.*;
-import akka.event.LoggingAdapter;
-import akka.event.Logging;
 import akka.japi.pf.ReceiveBuilder;
 import akka.testkit.ErrorFilter;
 import akka.testkit.EventFilter;
@@ -65,9 +63,8 @@ public class ActorDocTest {
   }
 
   @AfterClass
-  public static void afterClass() {
+  public static void afterClass() throws Exception {
-    system.shutdown();
+    Await.ready(system.terminate(), Duration.create("5 seconds"));
-    system.awaitTermination(Duration.create("5 seconds"));
   }
 
   static
@@ -316,7 +313,7 @@ public class ActorDocTest {
       swapper.tell(Swap, ActorRef.noSender()); // logs Ho
       swapper.tell(Swap, ActorRef.noSender()); // logs Hi
       swapper.tell(Swap, ActorRef.noSender()); // logs Ho
-      system.shutdown();
+      system.terminate();
     }
   }
   //#swapper

akka-samples/akka-docs-java-lambda/src/test/java/docs/actor/InitializationDocTest.java

@@ -10,11 +10,11 @@ import akka.testkit.JavaTestKit;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import scala.PartialFunction;
 import scala.concurrent.duration.Duration;
-import scala.runtime.BoxedUnit;
+import scala.concurrent.Await;
 
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 
 public class InitializationDocTest {
 
@@ -26,9 +26,8 @@ public class InitializationDocTest {
   }
 
   @AfterClass
-  public static void afterClass() {
+  public static void afterClass() throws Exception {
-    system.shutdown();
+      Await.ready(system.terminate(), Duration.create("5 seconds"));
-    system.awaitTermination(Duration.create("5 seconds"));
   }
 
   public static class MessageInitExample extends AbstractActor {

akka-samples/akka-docs-java-lambda/src/test/java/docs/actor/japi/FaultHandlingDocSample.java

@@ -19,11 +19,8 @@ import akka.util.Timeout;
 import com.typesafe.config.Config;
 import com.typesafe.config.ConfigFactory;
 import scala.concurrent.duration.Duration;
-import scala.PartialFunction;
-import scala.runtime.BoxedUnit;
 
 import static akka.japi.Util.classTag;
-import static akka.actor.SupervisorStrategy.resume;
 import static akka.actor.SupervisorStrategy.restart;
 import static akka.actor.SupervisorStrategy.stop;
 import static akka.actor.SupervisorStrategy.escalate;
@@ -79,13 +76,13 @@ public class FaultHandlingDocSample {
           log().info("Current progress: {} %", progress.percent);
           if (progress.percent >= 100.0) {
             log().info("That's all, shutting down");
-            context().system().shutdown();
+            context().system().terminate();
           }
         }).
         matchEquals(ReceiveTimeout.getInstance(), x -> {
           // No progress within 15 seconds, ServiceUnavailable
           log().error("Shutting down due to unavailable service");
-          context().system().shutdown();
+          context().system().terminate();
         }).build(), context()
       ));
     }

akka-samples/akka-sample-hello-kernel/src/main/java/sample/kernel/hello/java/HelloKernel.java

@@ -38,6 +38,6 @@ public class HelloKernel implements Bootable {
   }
 
   public void shutdown() {
-    system.shutdown();
+    system.terminate();
   }
 }

akka-samples/akka-sample-hello-kernel/src/main/scala/sample/kernel/hello/HelloKernel.scala

@@ -29,6 +29,6 @@ class HelloKernel extends Bootable {
   }
 
   def shutdown = {
-    system.shutdown()
+    system.terminate()
   }
 }

akka-samples/akka-sample-main-java-lambda/src/main/java/sample/hello/Main2.java

@@ -21,7 +21,7 @@ public class Main2 {
       receive(ReceiveBuilder.
         match(Terminated.class, t -> {
           log().info("{} has terminated, shutting down system", ref.path());
-          context().system().shutdown();
+          context().system().terminate();
         }).build());
     }
   }

akka-samples/akka-sample-main-java/src/main/java/sample/hello/Main2.java

@@ -30,7 +30,7 @@ public class Main2 {
     public void onReceive(Object msg) {
       if (msg instanceof Terminated) {
         log.info("{} has terminated, shutting down system", ref.path());
-        getContext().system().shutdown();
+        getContext().system().terminate();
       } else {
         unhandled(msg);
       }

akka-samples/akka-sample-main-scala/src/main/scala/sample/hello/Main2.scala

@@ -20,7 +20,7 @@ object Main2 {
     def receive = {
       case Terminated(_) =>
         log.info("{} has terminated, shutting down system", ref.path)
-        context.system.shutdown()
+        context.system.terminate()
     }
   }
 

akka-samples/akka-sample-persistence-java-lambda/src/main/java/sample/persistence/PersistentActorExample.java

@@ -125,6 +125,6 @@ public class PersistentActorExample {
         processor.tell("print", null);
 
         Thread.sleep(1000);
-        system.shutdown();
+        system.terminate();
     }
 }

akka-samples/akka-sample-persistence-java-lambda/src/main/java/sample/persistence/SnapshotExample.java

@@ -88,6 +88,6 @@ public class SnapshotExample {
     persistentActor.tell("print", null);
 
     Thread.sleep(1000);
-    system.shutdown();
+    system.terminate();
   }
 }

akka-samples/akka-sample-persistence-java/src/main/java/sample/persistence/PersistentActorExample.java

@@ -127,6 +127,6 @@ public class PersistentActorExample {
         persistentActor.tell("print", null);
 
         Thread.sleep(1000);
-        system.shutdown();
+        system.terminate();
     }
 }

akka-samples/akka-sample-persistence-java/src/main/java/sample/persistence/SnapshotExample.java

@@ -95,6 +95,6 @@ public class SnapshotExample {
         persistentActor.tell("print", null);
 
         Thread.sleep(1000);
-        system.shutdown();
+        system.terminate();
     }
 }

akka-samples/akka-sample-persistence-scala/src/main/scala/sample/persistence/PersistentActorExample.scala

@@ -56,5 +56,5 @@ object PersistentActorExample extends App {
   persistentActor ! "print"
 
   Thread.sleep(1000)
-  system.shutdown()
+  system.terminate()
 }

akka-samples/akka-sample-persistence-scala/src/main/scala/sample/persistence/SnapshotExample.scala

@@ -44,5 +44,5 @@ object SnapshotExample extends App {
   persistentActor ! "print"
 
   Thread.sleep(1000)
-  system.shutdown()
+  system.terminate()
 }

akka-samples/akka-sample-remote-scala/src/main/scala/sample/remote/benchmark/Receiver.scala

@@ -17,7 +17,7 @@ class Receiver extends Actor {
 
   def receive = {
     case m: Echo  => sender() ! m
-    case Shutdown => context.system.shutdown()
+    case Shutdown => context.system.terminate()
     case _        =>
   }
 }

akka-samples/akka-sample-remote-scala/src/main/scala/sample/remote/benchmark/Sender.scala

@@ -104,7 +104,7 @@ class Sender(path: String, totalMessages: Int, burstSize: Int, payloadSize: Int)
 
     case Terminated(`actor`) =>
       println("Receiver terminated")
-      context.system.shutdown()
+      context.system.terminate()
 
   }
 

akka-samples/akka-sample-supervision-java-lambda/src/main/java/supervision/Main.java

@@ -33,7 +33,6 @@ public class Main {
     Integer result = Await.result(ask(calculatorService, task, new Timeout(duration)).mapTo(classTag(Integer.class)), duration);
     System.out.println("Got result: " + result);
 
-    system.shutdown();
+    Await.ready(system.terminate(), Duration.Inf());
-    system.awaitTermination();
   }
 }

akka-testkit/src/main/scala/akka/testkit/TestKit.scala

@@ -6,6 +6,7 @@ package akka.testkit
 import language.postfixOps
 import scala.annotation.{ varargs, tailrec }
 import scala.collection.immutable
+import scala.concurrent.Await
 import scala.concurrent.duration._
 import scala.reflect.ClassTag
 import java.util.concurrent._
@@ -698,10 +699,14 @@ trait TestKitBase {
  *
  *     val test = system.actorOf(Props[SomeActor]
  *
- *     within (1 second) {
+ *       within (1 second) {
- *       test ! SomeWork
+ *         test ! SomeWork
- *       expectMsg(Result1) // bounded to 1 second
+ *         expectMsg(Result1) // bounded to 1 second
- *       expectMsg(Result2) // bounded to the remainder of the 1 second
+ *         expectMsg(Result2) // bounded to the remainder of the 1 second
+ *       }
+ *
+ *     } finally {
+ *       system.terminate()
  *     }
  *
  *   } finally {
@@ -768,8 +773,8 @@ object TestKit {
   def shutdownActorSystem(actorSystem: ActorSystem,
                           duration: Duration = 10.seconds,
                           verifySystemShutdown: Boolean = false): Unit = {
-    actorSystem.shutdown()
+    actorSystem.terminate()
-    try actorSystem.awaitTermination(duration) catch {
+    try Await.ready(actorSystem.whenTerminated, duration) catch {
       case _: TimeoutException ⇒
         val msg = "Failed to stop [%s] within [%s] \n%s".format(actorSystem.name, duration,
           actorSystem.asInstanceOf[ActorSystemImpl].printTree)

akka-testkit/src/test/scala/akka/testkit/DefaultTimeoutSpec.scala

@@ -13,7 +13,7 @@ class DefaultTimeoutSpec
 
   implicit lazy val system = ActorSystem("AkkaCustomSpec")
 
-  override def afterAll = system.shutdown
+  override def afterAll = system.terminate
 
   "A spec with DefaultTimeout" should {
     "use timeout from settings" in {

akka-testkit/src/test/scala/akka/testkit/ImplicitSenderSpec.scala

@@ -13,7 +13,7 @@ class ImplicitSenderSpec
 
   implicit lazy val system = ActorSystem("AkkaCustomSpec")
 
-  override def afterAll = system.shutdown
+  override def afterAll = system.terminate
 
   "An ImplicitSender" should {
     "have testActor as its self" in {

project/AkkaBuild.scala

@@ -457,7 +457,7 @@ object AkkaBuild extends Build {
          |var remoteConfig = ConfigFactory.parseString("akka.remote.netty{port=0,use-dispatcher-for-io=akka.actor.default-dispatcher,execution-pool-size=0},akka.actor.provider=akka.remote.RemoteActorRefProvider").withFallback(config)
          |var system: ActorSystem = null
          |implicit def _system = system
-         |def startSystem(remoting: Boolean = false) { system = ActorSystem("repl", if(remoting) remoteConfig else config); println("don’t forget to system.shutdown()!") }
+         |def startSystem(remoting: Boolean = false) { system = ActorSystem("repl", if(remoting) remoteConfig else config); println("don’t forget to system.terminate()!") }
          |implicit def ec = system.dispatcher
          |implicit val timeout = Timeout(5 seconds)
          |""".stripMargin,