Make Cluster ready for use before constructor returns, #2311

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

@@ -57,12 +57,6 @@ sealed trait ClusterMessage extends Serializable
  */
 object ClusterUserAction {
 
-  /**
-   * Command to initiate join another node (represented by 'address').
-   * Join will be sent to the other node.
-   */
-  case class JoinTo(address: Address) extends ClusterMessage
-
   /**
    * Command to join the cluster. Sent when a node (represented by 'address')
    * wants to join another node (the receiver).
@@ -84,7 +78,13 @@ object ClusterUserAction {
 /**
  * INTERNAL API
  */
-object InternalClusterAction {
+private[cluster] object InternalClusterAction {
+
+  /**
+   * Command to initiate join another node (represented by 'address').
+   * Join will be sent to the other node.
+   */
+  case class JoinTo(address: Address) extends ClusterMessage
 
   /**
    * Start message of the process to join one of the seed nodes.
@@ -133,25 +133,23 @@ object InternalClusterAction {
 
 }
 
-/**
- * Cluster commands sent by the LEADER.
- */
-object ClusterLeaderAction {
-
 /**
  * INTERNAL API.
  *
+ * Cluster commands sent by the LEADER.
+ */
+private[cluster] object ClusterLeaderAction {
+
+  /**
    * Command to mark a node to be removed from the cluster immediately.
    * Can only be sent by the leader.
    */
-  private[cluster] case class Exit(address: Address) extends ClusterMessage
+  case class Exit(address: Address) extends ClusterMessage
 
   /**
-   * INTERNAL API.
-   *
    * Command to remove a node from the cluster immediately.
    */
-  private[cluster] case class Remove(address: Address) extends ClusterMessage
+  case class Remove(address: Address) extends ClusterMessage
 }
 
 /**
@@ -683,7 +681,7 @@ private[cluster] final class ClusterCore(cluster: Cluster) extends Actor with Ac
     case InitJoin                         ⇒ initJoin()
     case InitJoinAck(address)             ⇒ join(address)
     case Failure(e: AskTimeoutException)  ⇒ joinSeedNodeTimeout()
-    case ClusterUserAction.JoinTo(address) ⇒ join(address)
+    case JoinTo(address)                  ⇒ join(address)
     case ClusterUserAction.Join(address)  ⇒ joining(address)
     case ClusterUserAction.Down(address)  ⇒ downing(address)
     case ClusterUserAction.Leave(address) ⇒ leaving(address)
@@ -1341,10 +1339,10 @@ private[cluster] final class ClusterDaemonSupervisor(cluster: Cluster) extends A
   val heartbeat = context.actorOf(Props(new ClusterHeartbeatDaemon(cluster)).
     withDispatcher(configuredDispatcher), name = "heartbeat")
 
-  def receive = Actor.emptyBehavior
+  def receive = {
+    case InternalClusterAction.GetClusterCoreRef ⇒ sender ! core
+  }
 
-  override def unhandled(unknown: Any): Unit = log.error("[{}] can not respond to messages - received [{}]",
-    self.path, unknown)
 }
 
 /**
@@ -1474,20 +1472,17 @@ class Cluster(system: ExtendedActorSystem, val failureDetector: FailureDetector)
 
   // create supervisor for daemons under path "/system/cluster"
   private val clusterDaemons: ActorRef = {
-    implicit val timeout = Timeout(remoteSettings.RemoteSystemDaemonAckTimeout)
-    val createChild = CreateChild(Props(new ClusterDaemonSupervisor(this)).
+    system.asInstanceOf[ActorSystemImpl].systemActorOf(Props(new ClusterDaemonSupervisor(this)).
       withDispatcher(UseDispatcher), name = "cluster")
-    Await.result(system.systemGuardian ? createChild, timeout.duration) match {
-      case a: ActorRef  ⇒ a
-      case e: Exception ⇒ throw e
-    }
   }
 
   /**
    * INTERNAL API
    */
-  private[cluster] def clusterCore: ActorRef =
-    system.actorFor(clusterDaemons.path / "core")
+  private[cluster] val clusterCore: ActorRef = {
+    implicit val timeout = system.settings.CreationTimeout
+    Await.result((clusterDaemons ? InternalClusterAction.GetClusterCoreRef).mapTo[ActorRef], timeout.duration)
+  }
 
   system.registerOnTermination(shutdown())
 
@@ -1584,7 +1579,7 @@ class Cluster(system: ExtendedActorSystem, val failureDetector: FailureDetector)
    * A 'Join(thisNodeAddress)' command is sent to the node to join.
    */
   def join(address: Address): Unit =
-    clusterCore ! ClusterUserAction.JoinTo(address)
+    clusterCore ! InternalClusterAction.JoinTo(address)
 
   /**
    * Send command to issue state transition to LEAVING for the node specified by 'address'.