SI-6442 - Add ActorDSL object for actor migration kit

Removes MigrationSystem, since ActorDSL replaces it.

3 files changed, 61 insertions, 42 deletions

diff --git a/src/actors-migration/scala/actors/migration/ActorDSL.scala b/src/actors-migration/scala/actors/migration/ActorDSL.scala
new file mode 100644
index 0000000000..b8cb8ec998
--- /dev/null
+++ b/src/actors-migration/scala/actors/migration/ActorDSL.scala
@@ -0,0 +1,56 @@
+/*                     __                                               *\
+**     ________ ___   / /  ___     Scala API                            **
+**    / __/ __// _ | / /  / _ |    (c) 2005-2011, LAMP/EPFL             **
+**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
+** /____/\___/_/ |_/____/_/ | |                                         **
+**                          |/                                          **
+\*                                                                      */
+
+package scala.actors
+package migration
+
+import scala.actors.{ Actor, ActorRef, InternalActorRef }
+import scala.collection.immutable
+import scala.reflect.ClassTag
+
+object ActorDSL {
+
+  private[migration] val contextStack = new ThreadLocal[immutable.Stack[Boolean]] {
+    override def initialValue() = immutable.Stack[Boolean]()
+  }
+
+  private[this] def withCleanContext(block: => ActorRef): ActorRef = {
+    // push clean marker
+    val old = contextStack.get
+    contextStack.set(old.push(true))
+    try {
+      val instance = block
+
+      if (instance eq null)
+        throw new Exception("ActorRef can't be 'null'")
+
+      instance
+    } finally {
+      val stackAfter = contextStack.get
+      if (stackAfter.nonEmpty)
+        contextStack.set(if (!stackAfter.head) stackAfter.pop.pop else stackAfter.pop)
+    }
+  }
+  
+  /**
+   * Create an actor from the given thunk which must produce an [[scala.actors.Actor]].
+   *
+   * @param ctor is a by-name argument which captures an [[scala.actors.Actor]]
+   *        factory; <b>do not make the generated object accessible to code
+   *        outside and do not return the same object upon subsequent invocations.</b>
+   */
+  def actor[T <: InternalActor: ClassTag](ctor: ⇒ T): ActorRef = {
+    withCleanContext {
+      val newActor = ctor
+      val newRef = new InternalActorRef(newActor)
+      newActor.start()
+      newRef
+    }
+  }
+
+}
diff --git a/src/actors-migration/scala/actors/migration/MigrationSystem.scala b/src/actors-migration/scala/actors/migration/MigrationSystem.scala
deleted file mode 100644
index 3dcb38e634..0000000000
--- a/src/actors-migration/scala/actors/migration/MigrationSystem.scala
+++ /dev/null
@@ -1,37 +0,0 @@
-package scala.actors.migration
-
-import scala.actors._
-import scala.collection._
-
-object MigrationSystem {
-
-  private[migration] val contextStack = new ThreadLocal[immutable.Stack[Boolean]] {
-    override def initialValue() = immutable.Stack[Boolean]()
-  }
-
-  private[this] def withCleanContext(block: => ActorRef): ActorRef = {
-    // push clean marker
-    val old = contextStack.get
-    contextStack.set(old.push(true))
-    try {
-      val instance = block
-
-      if (instance eq null)
-        throw new Exception("Actor instance passed to actorOf can't be 'null'")
-
-      instance
-    } finally {
-      val stackAfter = contextStack.get
-      if (stackAfter.nonEmpty)
-        contextStack.set(if (!stackAfter.head) stackAfter.pop.pop else stackAfter.pop)
-    }
-  }
-
-  def actorOf(props: Props): ActorRef = withCleanContext {
-    val creator = props.creator()
-    val r = new InternalActorRef(creator)
-    creator.start()
-    r
-  }
-
-}
\ No newline at end of file
diff --git a/src/actors-migration/scala/actors/migration/StashingActor.scala b/src/actors-migration/scala/actors/migration/StashingActor.scala
index d0a1432e72..c628035891 100644
--- a/src/actors-migration/scala/actors/migration/StashingActor.scala
+++ b/src/actors-migration/scala/actors/migration/StashingActor.scala
@@ -110,18 +110,18 @@ trait StashingActor extends InternalActor {
   private[actors] var behaviorStack = immutable.Stack[PartialFunction[Any, Unit]]()
 
   /*
-   * Checks that StashingActor can be created only by MigrationSystem.actorOf method.
+   * Checks that StashingActor instances can only be created using the ActorDSL.
    */
   private[this] def creationCheck(): Unit = {
     // creation check (see ActorRef)
-    val context = MigrationSystem.contextStack.get
+    val context = ActorDSL.contextStack.get
     if (context.isEmpty)
-      throw new RuntimeException("In order to create StashingActor one must use actorOf.")
+      throw new RuntimeException("In order to create a StashingActor one must use the ActorDSL object")
     else {
       if (!context.head)
-        throw new RuntimeException("Only one actor can be created per actorOf call.")
+        throw new RuntimeException("Cannot create more than one actor")
       else
-        MigrationSystem.contextStack.set(context.push(false))
+        ActorDSL.contextStack.set(context.push(false))
     }
 
   }