#19197 implement SubFusingActorMaterializer

and use it in FlattenMerge

akka-stream-tests/src/test/scala/akka/stream/FusingSpec.scala

@@ -11,11 +11,16 @@ import akka.stream.Attributes._
 import akka.stream.Fusing.FusedGraph
 import scala.annotation.tailrec
 import akka.stream.impl.StreamLayout.Module
+import org.scalatest.concurrent.ScalaFutures
+import scala.concurrent.duration._
+import akka.stream.impl.fusing.GraphInterpreter
+import akka.event.BusLogging
 
-class FusingSpec extends AkkaSpec with ConversionCheckedTripleEquals {
+class FusingSpec extends AkkaSpec with ScalaFutures with ConversionCheckedTripleEquals {
 
   final val Debug = false
   implicit val materializer = ActorMaterializer()
+  implicit val patience = PatienceConfig(1.second)
 
   def graph(async: Boolean) =
     Source.unfoldInf(1)(x ⇒ (x, x)).filter(_ % 2 == 1)
@@ -87,4 +92,38 @@ class FusingSpec extends AkkaSpec with ConversionCheckedTripleEquals {
 
   }
 
+  "SubFusingActorMaterializer" must {
+
+    "work with asynchronous boundaries in the subflows" in {
+      val async = Flow[Int].map(_ * 2).withAttributes(Attributes.asyncBoundary)
+      Source(0 to 9)
+        .map(_ * 10)
+        .flatMapMerge(5, i ⇒ Source(i to (i + 9)).via(async))
+        .grouped(1000)
+        .runWith(Sink.head)
+        .futureValue
+        .sorted should ===(0 to 198 by 2)
+    }
+
+    "use multiple actors when there are asynchronous boundaries in the subflows" in {
+      def ref = {
+        val bus = GraphInterpreter.currentInterpreter.log.asInstanceOf[BusLogging]
+        bus.logSource
+      }
+      val async = Flow[Int].map(x ⇒ { testActor ! ref; x }).withAttributes(Attributes.asyncBoundary)
+      Source(0 to 9)
+        .map(x ⇒ { testActor ! ref; x })
+        .flatMapMerge(5, i ⇒ Source.single(i).via(async))
+        .grouped(1000)
+        .runWith(Sink.head)
+        .futureValue
+        .sorted should ===(0 to 9)
+      val refs = receiveN(20)
+      withClue(s"refs=\n${refs.mkString("\n")}") {
+        refs.toSet.size should ===(11)
+      }
+    }
+
+  }
+
 }

akka-stream-tests/src/test/scala/akka/stream/impl/fusing/GraphInterpreterSpec.scala

@@ -56,7 +56,7 @@ class GraphInterpreterSpec extends AkkaSpec with GraphInterpreterSpecKit {
       manualInit(assembly)
       interpreter.attachDownstreamBoundary(2, sink)
       interpreter.attachUpstreamBoundary(0, source)
-      interpreter.init()
+      interpreter.init(null)
 
       lastEvents() should ===(Set.empty)
 

akka-stream-tests/src/test/scala/akka/stream/impl/fusing/GraphInterpreterSpecKit.scala

@@ -84,7 +84,7 @@ trait GraphInterpreterSpecKit extends AkkaSpec {
           _interpreter.attachDownstreamBoundary(i + upstreams.size + connections.size, downstream._2)
         }
 
-        _interpreter.init()
+        _interpreter.init(null)
       }
     }
 
@@ -226,7 +226,7 @@ trait GraphInterpreterSpecKit extends AkkaSpec {
     manualInit(assembly)
     interpreter.attachDownstreamBoundary(0, in)
     interpreter.attachUpstreamBoundary(0, out)
-    interpreter.init()
+    interpreter.init(null)
   }
 
   abstract class FailingStageSetup(initFailOnNextEvent: Boolean = false) extends TestSetup {
@@ -351,7 +351,7 @@ trait GraphInterpreterSpecKit extends AkkaSpec {
       interpreter.attachUpstreamBoundary(0, upstream)
       interpreter.attachDownstreamBoundary(ops.length, downstream)
 
-      interpreter.init()
+      interpreter.init(null)
 
     }
 

akka-stream-tests/src/test/scala/akka/stream/scaladsl/FlowSpec.scala

@@ -22,6 +22,7 @@ import scala.collection.immutable
 import scala.concurrent.Await
 import scala.concurrent.duration._
 import scala.util.control.NoStackTrace
+import akka.stream.impl.fusing.GraphInterpreterShell
 
 object FlowSpec {
   class Fruit
@@ -41,22 +42,14 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
   val identity: Flow[Any, Any, Unit] ⇒ Flow[Any, Any, Unit] = in ⇒ in.map(e ⇒ e)
   val identity2: Flow[Any, Any, Unit] ⇒ Flow[Any, Any, Unit] = in ⇒ identity(in)
 
-  class BrokenActorInterpreter(
-    _assembly: GraphAssembly,
-    _inHandlers: Array[InHandler],
-    _outHandlers: Array[OutHandler],
-    _logics: Array[GraphStageLogic],
-    _shape: Shape,
-    _settings: ActorMaterializerSettings,
-    _materializer: Materializer,
-    brokenMessage: Any)
-    extends ActorGraphInterpreter(_assembly, _inHandlers, _outHandlers, _logics, _shape, _settings, _materializer) {
+  class BrokenActorInterpreter(_shell: GraphInterpreterShell, brokenMessage: Any)
+    extends ActorGraphInterpreter(_shell) {
 
     import akka.stream.actor.ActorSubscriberMessage._
 
     override protected[akka] def aroundReceive(receive: Receive, msg: Any) = {
       msg match {
-        case ActorGraphInterpreter.OnNext(0, m) if m == brokenMessage ⇒
+        case ActorGraphInterpreter.OnNext(_, 0, m) if m == brokenMessage ⇒
           throw new NullPointerException(s"I'm so broken [$m]")
         case _ ⇒ super.aroundReceive(receive, msg)
       }
@@ -77,14 +70,17 @@ class FlowSpec extends AkkaSpec(ConfigFactory.parseString("akka.actor.debug.rece
     val (inHandlers, outHandlers, logics) =
       assembly.materialize(Attributes.none, assembly.stages.map(_.module), new java.util.HashMap, _ ⇒ ())
 
-    val props = Props(new BrokenActorInterpreter(assembly, inHandlers, outHandlers, logics, stage.shape, settings, materializer, "a3"))
+    val shell = new GraphInterpreterShell(assembly, inHandlers, outHandlers, logics, stage.shape, settings,
+      materializer.asInstanceOf[ActorMaterializerImpl])
+
+    val props = Props(new BrokenActorInterpreter(shell, "a3"))
       .withDispatcher("akka.test.stream-dispatcher").withDeploy(Deploy.local)
     val impl = system.actorOf(props, "borken-stage-actor")
 
-    val subscriber = new ActorGraphInterpreter.BoundarySubscriber(impl, 0)
-    val publisher = new ActorPublisher[Any](impl) { override val wakeUpMsg = ActorGraphInterpreter.SubscribePending(0) }
+    val subscriber = new ActorGraphInterpreter.BoundarySubscriber(impl, shell, 0)
+    val publisher = new ActorPublisher[Any](impl) { override val wakeUpMsg = ActorGraphInterpreter.SubscribePending(shell, 0) }
 
-    impl ! ActorGraphInterpreter.ExposedPublisher(0, publisher)
+    impl ! ActorGraphInterpreter.ExposedPublisher(shell, 0, publisher)
 
     Flow.fromSinkAndSource(Sink(subscriber), Source(publisher))
   })