Make SingleConsumerMultiProducer the default mail box for typed

akka-actor-typed-tests/src/test/scala/akka/actor/typed/internal/adpater/PropsAdapterSpec.scala

@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2019 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package akka.actor.typed.internal.adpater
+
+import akka.actor
+import akka.actor.typed.Props
+import akka.actor.typed.internal.adapter.PropsAdapter
+import akka.actor.typed.scaladsl.Behaviors
+import org.scalatest.Matchers
+import org.scalatest.WordSpec
+
+class PropsAdapterSpec extends WordSpec with Matchers {
+
+  "PropsAdapter" should {
+    "default to akka.dispatch.SingleConsumerOnlyUnboundedMailbox" in {
+      val props: Props = Props.empty
+      val pa: actor.Props = PropsAdapter(() => Behaviors.empty, props)
+      pa.mailbox shouldEqual "akka.dispatch.SingleConsumerOnlyUnboundedMailbox"
+    }
+  }
+}

akka-actor-typed/src/main/scala/akka/actor/typed/Props.scala

@@ -189,12 +189,12 @@ abstract class MailboxSelector extends Props
 object MailboxSelector {
 
   /**
-   * Scala API: The default mailbox is unbounded and backed by a [[java.util.concurrent.ConcurrentLinkedQueue]]
+   * Scala API: The default mailbox is SingleConsumerOnlyUnboundedMailbox
    */
-  def default(): MailboxSelector = DefaultMailboxSelector.empty
+  def default(): MailboxSelector = fromConfig("akka.dispatch.SingleConsumerOnlyUnboundedMailbox")
 
   /**
-   * Java API: The default mailbox is unbounded and backed by a [[java.util.concurrent.ConcurrentLinkedQueue]]
+   * Java API: The default mailbox is SingleConsumerOnlyUnboundedMailbox
    */
   def defaultMailbox(): MailboxSelector = default()
 

akka-actor-typed/src/main/scala/akka/actor/typed/internal/adapter/PropsAdapter.scala

@@ -23,22 +23,22 @@ import akka.dispatch.Mailboxes
       rethrowTypedFailure: Boolean = true): akka.actor.Props = {
     val props = akka.actor.Props(new ActorAdapter(behavior(), rethrowTypedFailure))
 
-    val p1 = (deploy.firstOrElse[DispatcherSelector](DispatcherDefault.empty) match {
+    val dispatcherProps = (deploy.firstOrElse[DispatcherSelector](DispatcherDefault.empty) match {
       case _: DispatcherDefault          => props
       case DispatcherFromConfig(name, _) => props.withDispatcher(name)
       case _: DispatcherSameAsParent     => props.withDispatcher(Deploy.DispatcherSameAsParent)
     }).withDeploy(Deploy.local) // disallow remote deployment for typed actors
 
-    val p2 = deploy.firstOrElse[MailboxSelector](MailboxSelector.default()) match {
-      case _: DefaultMailboxSelector           => p1
+    val mailboxProps = deploy.firstOrElse[MailboxSelector](MailboxSelector.default()) match {
+      case _: DefaultMailboxSelector           => dispatcherProps
       case BoundedMailboxSelector(capacity, _) =>
         // specific support in classic Mailboxes
-        p1.withMailbox(s"${Mailboxes.BoundedCapacityPrefix}$capacity")
+        dispatcherProps.withMailbox(s"${Mailboxes.BoundedCapacityPrefix}$capacity")
       case MailboxFromConfigSelector(path, _) =>
         props.withMailbox(path)
     }
 
-    p2.withDeploy(Deploy.local) // disallow remote deployment for typed actors
+    mailboxProps.withDeploy(Deploy.local) // disallow remote deployment for typed actors
   }
 
 }

akka-bench-jmh/src/main/scala/akka/actor/typed/TypedActorBenchmark.scala

@@ -15,7 +15,7 @@ import akka.actor.typed.scaladsl.AskPattern._
 
 object TypedActorBenchmark {
   // Constants because they are used in annotations
-  final val threads = 12 // update according to cpu
+  final val threads = 8 // update according to cpu
   final val numMessagesPerActorPair = 1000000 // messages per actor pair
 
   final val numActors = 512

akka-docs/src/main/paradox/typed/mailboxes.md

@@ -83,20 +83,7 @@ be used.
 
 ### Default Mailbox
 
-The default mailbox is used when the mailbox is not specified.
-This is an unbounded mailbox, backed by a
-`java.util.concurrent.ConcurrentLinkedQueue`.
-
-`SingleConsumerOnlyUnboundedMailbox` is an even more efficient mailbox, and
-it can be used as the default mailbox, but it cannot be used with a BalancingDispatcher.
-
-Configuration of `SingleConsumerOnlyUnboundedMailbox` as default mailbox:
-
-```
-akka.actor.default-mailbox {
-  mailbox-type = "akka.dispatch.SingleConsumerOnlyUnboundedMailbox"
-}
-```
+The default mailbox is used when the mailbox is not specified and is the **SingleConsumerOnlyUnboundedMailbox**>
 
 ### Which Configuration is passed to the Mailbox Type
 
@@ -112,19 +99,19 @@ fall-back to the default mailbox configuration section.
 Akka ships with a number of mailbox implementations:
 
  * 
-   **UnboundedMailbox** (default)
-    * The default mailbox
-    * Backed by a `java.util.concurrent.ConcurrentLinkedQueue`
-    * Blocking: No
-    * Bounded: No
-    * Configuration name: `"unbounded"` or `"akka.dispatch.UnboundedMailbox"`
- * 
-   **SingleConsumerOnlyUnboundedMailbox**
-   Depending on your use case, this queue may or may not be faster than the default one — be sure to benchmark properly!
+   **SingleConsumerOnlyUnboundedMailbox** (default)
+    * This is the default
     * Backed by a Multiple-Producer Single-Consumer queue, cannot be used with `BalancingDispatcher`
     * Blocking: No
     * Bounded: No
     * Configuration name: `"akka.dispatch.SingleConsumerOnlyUnboundedMailbox"`
+ * 
+   **UnboundedMailbox**
+    * Backed by a `java.util.concurrent.ConcurrentLinkedQueue`
+    * Blocking: No
+    * Bounded: No
+    * Configuration name: `"unbounded"` or `"akka.dispatch.UnboundedMailbox"`
+
  * 
    **NonBlockingBoundedMailbox**
     * Backed by a very efficient Multiple-Producer Single-Consumer queue