+act #3900 make systemActorOf available to Extensions

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

@@ -88,7 +88,7 @@ object ActorDSL extends dsl.Inbox with dsl.Creators {
 
   protected class Extension(val system: ExtendedActorSystem) extends akka.actor.Extension with InboxExtension {
 
-    val boss = system.asInstanceOf[ActorSystemImpl].systemActorOf(Props(
+    val boss = system.systemActorOf(Props(
       new Actor {
         def receive = { case any ⇒ sender() ! any }
       }), "dsl").asInstanceOf[RepointableActorRef]

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

@@ -463,6 +463,12 @@ abstract class ExtendedActorSystem extends ActorSystem {
    */
   def systemGuardian: InternalActorRef
 
+  /**
+   * Create an actor in the "/system" namespace. This actor will be shut down
+   * during system shutdown only after all user actors have terminated.
+   */
+  def systemActorOf(props: Props, name: String): ActorRef
+
   /**
    * A ThreadFactory that can be used if the transport needs to create any Threads
    */
@@ -541,7 +547,7 @@ private[akka] class ActorSystemImpl(val name: String, applicationConfig: Config,
 
   protected def systemImpl: ActorSystemImpl = this
 
-  private[akka] def systemActorOf(props: Props, name: String): ActorRef = systemGuardian.underlying.attachChild(props, name, systemService = true)
+  def systemActorOf(props: Props, name: String): ActorRef = systemGuardian.underlying.attachChild(props, name, systemService = true)
 
   def actorOf(props: Props, name: String): ActorRef = guardian.underlying.attachChild(props, name, systemService = false)
 

akka-actor/src/main/scala/akka/io/Tcp.scala

@@ -556,7 +556,7 @@ class TcpExt(system: ExtendedActorSystem) extends IO.Extension {
    *
    */
   val manager: ActorRef = {
-    system.asInstanceOf[ActorSystemImpl].systemActorOf(
+    system.systemActorOf(
       props = Props(classOf[TcpManager], this).withDispatcher(Settings.ManagementDispatcher).withDeploy(Deploy.local),
       name = "IO-TCP")
   }

akka-actor/src/main/scala/akka/io/Udp.scala

@@ -212,7 +212,7 @@ class UdpExt(system: ExtendedActorSystem) extends IO.Extension {
   val settings: UdpSettings = new UdpSettings(system.settings.config.getConfig("akka.io.udp"))
 
   val manager: ActorRef = {
-    system.asInstanceOf[ActorSystemImpl].systemActorOf(
+    system.systemActorOf(
       props = Props(classOf[UdpManager], this).withDeploy(Deploy.local),
       name = "IO-UDP-FF")
   }

akka-actor/src/main/scala/akka/io/UdpConnected.scala

@@ -149,7 +149,7 @@ class UdpConnectedExt(system: ExtendedActorSystem) extends IO.Extension {
   val settings: UdpSettings = new UdpSettings(system.settings.config.getConfig("akka.io.udp-connected"))
 
   val manager: ActorRef = {
-    system.asInstanceOf[ActorSystemImpl].systemActorOf(
+    system.systemActorOf(
       props = Props(classOf[UdpConnectedManager], this).withDeploy(Deploy.local),
       name = "IO-UDP-CONN")
   }

akka-cluster/src/main/scala/akka/cluster/Cluster.scala

@@ -157,7 +157,7 @@ class Cluster(val system: ExtendedActorSystem) extends Extension {
 
   // create supervisor for daemons under path "/system/cluster"
   private val clusterDaemons: ActorRef = {
-    system.asInstanceOf[ActorSystemImpl].systemActorOf(Props(classOf[ClusterDaemon], settings).
+    system.systemActorOf(Props(classOf[ClusterDaemon], settings).
       withDispatcher(UseDispatcher).withDeploy(Deploy.local), name = "cluster")
   }
 

akka-cluster/src/main/scala/akka/cluster/ClusterReadView.scala

@@ -45,7 +45,7 @@ private[akka] class ClusterReadView(cluster: Cluster) extends Closeable {
 
   // create actor that subscribes to the cluster eventBus to update current read view state
   private val eventBusListener: ActorRef = {
-    cluster.system.asInstanceOf[ActorSystemImpl].systemActorOf(Props(new Actor with RequiresMessageQueue[UnboundedMessageQueueSemantics] {
+    cluster.system.systemActorOf(Props(new Actor with RequiresMessageQueue[UnboundedMessageQueueSemantics] {
       override def preStart(): Unit = cluster.subscribe(self, classOf[ClusterDomainEvent])
       override def postStop(): Unit = cluster.unsubscribe(self)
 

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

@@ -217,7 +217,6 @@ trait ConsumerBehavior {
   }
 }
 
-
 class Producer extends Actor with ProducerBehavior {
   def receive = producerBehavior
 }
@@ -226,10 +225,9 @@ class Consumer extends Actor with ActorLogging with ConsumerBehavior {
   def receive = consumerBehavior
 }
 
-
 class ProducerConsumer extends Actor with ActorLogging
   with ProducerBehavior with ConsumerBehavior {
-  
+
   def receive = producerBehavior orElse consumerBehavior
 }
 

akka-persistence/src/main/scala/akka/persistence/Persistence.scala

@@ -93,11 +93,11 @@ class Persistence(val system: ExtendedActorSystem) extends Extension {
     else DefaultPluginDispatcherId
   }
 
-  private val confirmationBatchLayer = system.asInstanceOf[ActorSystemImpl]
+  private val confirmationBatchLayer = system.systemActorOf(
-    .systemActorOf(Props(classOf[DeliveredByChannelBatching], journal, settings), "confirmation-batch-layer")
+    Props(classOf[DeliveredByChannelBatching], journal, settings), "confirmation-batch-layer")
 
-  private val deletionBatchLayer = system.asInstanceOf[ActorSystemImpl]
+  private val deletionBatchLayer = system.systemActorOf(
-    .systemActorOf(Props(classOf[DeliveredByPersistentChannelBatching], journal, settings), "deletion-batch-layer")
+    Props(classOf[DeliveredByPersistentChannelBatching], journal, settings), "deletion-batch-layer")
 
   /**
    * Creates a canonical processor id from a processor actor ref.
@@ -145,7 +145,7 @@ class Persistence(val system: ExtendedActorSystem) extends Extension {
     val pluginClassName = pluginConfig.getString("class")
     val pluginClass = system.dynamicAccess.getClassFor[AnyRef](pluginClassName).get
     val pluginDispatcherId = if (pluginConfig.hasPath("plugin-dispatcher")) pluginConfig.getString("plugin-dispatcher") else dispatcherSelector(pluginClass)
-    system.asInstanceOf[ActorSystemImpl].systemActorOf(Props(pluginClass).withDispatcher(pluginDispatcherId), pluginType)
+    system.systemActorOf(Props(pluginClass).withDispatcher(pluginDispatcherId), pluginType)
   }
 
   private def id(ref: ActorRef) = ref.path.toStringWithoutAddress

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

@@ -114,7 +114,7 @@ private[remote] class Remoting(_system: ExtendedActorSystem, _provider: RemoteAc
 
   import provider.remoteSettings._
 
-  val transportSupervisor = system.asInstanceOf[ActorSystemImpl].systemActorOf(
+  val transportSupervisor = system.systemActorOf(
     configureDispatcher(Props[TransportSupervisor]),
     "transports")
 
@@ -159,7 +159,7 @@ private[remote] class Remoting(_system: ExtendedActorSystem, _provider: RemoteAc
     endpointManager match {
       case None ⇒
         log.info("Starting remoting")
-        val manager: ActorRef = system.asInstanceOf[ActorSystemImpl].systemActorOf(
+        val manager: ActorRef = system.systemActorOf(
           configureDispatcher(Props(classOf[EndpointManager], provider.remoteSettings.config, log)).withDeploy(Deploy.local),
           Remoting.EndpointManagerName)
         endpointManager = Some(manager)

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

@@ -120,7 +120,7 @@ trait TestKitBase {
    * registration as message target.
    */
   val testActor: ActorRef = {
-    val impl = system.asInstanceOf[ActorSystemImpl] //TODO ticket #1559
+    val impl = system.asInstanceOf[ExtendedActorSystem]
     val ref = impl.systemActorOf(TestActor.props(queue)
       .withDispatcher(CallingThreadDispatcher.Id),
       "testActor" + TestKit.testActorId.incrementAndGet)