Remove superflous ownerId fields in interpreter Connection #22447

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

@@ -110,11 +110,9 @@ object GraphInterpreterSpecKit {
 
         val connection = new Connection(
           id = idx,
-          outOwnerId = outOwner.stageId,
           outOwner = outOwner,
           outHandler = outOwner.outHandler(0),
           inOwner = inOwner,
-          inOwnerId = inOwner.stageId,
           inHandler = inOwner.inHandler(0)
         )
 
@@ -143,10 +141,8 @@ object GraphInterpreterSpecKit {
 
         val connection = new Connection(
           id = idx,
-          outOwnerId = outOwner.stageId,
           outOwner = outOwner,
           outHandler = outOwner.outHandler(outlet.id),
-          inOwnerId = inOwner.stageId,
           inOwner = inOwner,
           inHandler = inOwner.inHandler(inlet.id)
         )

akka-stream/src/main/scala/akka/stream/impl/PhasedFusingActorMaterializer.scala

@@ -616,14 +616,14 @@ final class GraphStageIsland(
     val c = connections(slot)
     if (c ne null) c
     else {
-      val c2 = new Connection(0, 0, null, 0, null, null, null)
+      val c2 = new Connection(0, null, null, null, null)
       connections(slot) = c2
       c2
     }
   }
 
   def outConn(): Connection = {
-    val connection = new Connection(0, 0, null, 0, null, null, null)
+    val connection = new Connection(0, null, null, null, null)
     outConnections ::= connection
     connection
   }
@@ -632,7 +632,6 @@ final class GraphStageIsland(
     val connection = conn(slot)
     connection.inOwner = logic
     connection.id = slot
-    connection.inOwnerId = logic.stageId
     connection.inHandler = logic.handlers(in.id).asInstanceOf[InHandler]
     logic.portToConn(in.id) = connection
   }
@@ -641,7 +640,6 @@ final class GraphStageIsland(
     val connection = conn(slot)
     connection.outOwner = logic
     connection.id = slot
-    connection.outOwnerId = logic.stageId
     connection.outHandler = logic.handlers(logic.inCount + out.id).asInstanceOf[OutHandler]
     logic.portToConn(logic.inCount + out.id) = connection
   }
@@ -655,11 +653,9 @@ final class GraphStageIsland(
     boundary.portToConn(boundary.in.id) = connection
     connection.inHandler = boundary.handlers(0).asInstanceOf[InHandler]
     connection.inOwner = boundary
-    connection.inOwnerId = boundary.stageId
 
     connection.outOwner = logic
     connection.id = -1 // Will be filled later
-    connection.outOwnerId = logic.stageId
     connection.outHandler = logic.handlers(logic.inCount + out.id).asInstanceOf[OutHandler]
     logic.portToConn(logic.inCount + out.id) = connection
 
@@ -678,7 +674,6 @@ final class GraphStageIsland(
     boundary.portToConn(boundary.out.id + boundary.inCount) = connection
     connection.outHandler = boundary.handlers(0).asInstanceOf[OutHandler]
     connection.outOwner = boundary
-    connection.outOwnerId = boundary.stageId
   }
 
   override def onIslandReady(): Unit = {

akka-stream/src/main/scala/akka/stream/impl/fusing/GraphInterpreter.scala

@@ -65,18 +65,14 @@ object GraphInterpreter {
    * between an output and input ports.
    *
    * @param id Identifier of the connection.
-   * @param inOwnerId Identifier of the owner of the input side of the connection.
    * @param inOwner The stage logic that corresponds to the input side of the connection.
-   * @param outOwnerId Identifier of the owner of the output side of the connection.
    * @param outOwner The stage logic that corresponds to the output side of the connection.
    * @param inHandler The handler that contains the callback for input events.
    * @param outHandler The handler that contains the callback for output events.
    */
   final class Connection(
     var id:         Int,
-    var inOwnerId:  Int,
     var inOwner:    GraphStageLogic,
-    var outOwnerId: Int,
     var outOwner:   GraphStageLogic,
     var inHandler:  InHandler,
     var outHandler: OutHandler) {
@@ -84,7 +80,7 @@ object GraphInterpreter {
     var slot: Any = Empty
 
     override def toString =
-      if (GraphInterpreter.Debug) s"Connection($id, $inOwnerId, $inOwner, $outOwnerId, $outOwner, $inHandler, $outHandler, $portState, $slot)"
+      if (GraphInterpreter.Debug) s"Connection($id, $inOwner, $outOwner, $inHandler, $outHandler, $portState, $slot)"
       else s"Connection($id, $portState, $slot, $inHandler, $outHandler)"
   }
 
@@ -121,7 +117,6 @@ object GraphInterpreter {
  * From an external viewpoint, the GraphInterpreter takes an assembly of graph processing stages encoded as a
  * [[GraphInterpreter#GraphAssembly]] object and provides facilities to execute and interact with this assembly.
  * The lifecycle of the Interpreter is roughly the following:
- *  - Boundary logics are attached via [[attachDownstreamBoundary()]] and [[attachUpstreamBoundary()]]
  *  - [[init()]] is called
  *  - [[execute()]] is called whenever there is need for execution, providing an upper limit on the processed events
  *  - [[finish()]] is called before the interpreter is disposed, preferably after [[isCompleted]] returned true, although
@@ -323,10 +318,10 @@ final class GraphInterpreter(
   private def outOwnerName(connection: Connection): String = connection.outOwner.toString
 
   // Debug name for a connections input part
-  private def inLogicName(connection: Connection): String = logics(connection.inOwnerId).toString
+  private def inLogicName(connection: Connection): String = logics(connection.inOwner.stageId).toString
 
   // Debug name for a connections output part
-  private def outLogicName(connection: Connection): String = logics(connection.outOwnerId).toString
+  private def outLogicName(connection: Connection): String = logics(connection.outOwner.stageId).toString
 
   private def shutdownCounters: String =
     shutdownCounter.map(x ⇒ if (x >= KeepGoingFlag) s"${x & KeepGoingMask}(KeepGoing)" else x.toString).mkString(",")
@@ -476,7 +471,7 @@ final class GraphInterpreter(
       activeStage = connection.outOwner
       if (Debug) println(s"$Name CANCEL ${inOwnerName(connection)} -> ${outOwnerName(connection)} (${connection.outHandler}) [${outLogicName(connection)}]")
       connection.portState |= OutClosed
-      completeConnection(connection.outOwnerId)
+      completeConnection(connection.outOwner.stageId)
       connection.outHandler.onDownstreamFinish()
     } else if ((code & (OutClosed | InClosed)) == OutClosed) {
       // COMPLETIONS
@@ -486,7 +481,7 @@ final class GraphInterpreter(
         if (Debug) println(s"$Name COMPLETE ${outOwnerName(connection)} -> ${inOwnerName(connection)} (${connection.inHandler}) [${inLogicName(connection)}]")
         connection.portState |= InClosed
         activeStage = connection.inOwner
-        completeConnection(connection.inOwnerId)
+        completeConnection(connection.inOwner.stageId)
         if ((connection.portState & InFailed) == 0) connection.inHandler.onUpstreamFinish()
         else connection.inHandler.onUpstreamFailure(connection.slot.asInstanceOf[Failed].ex)
       } else {
@@ -587,7 +582,7 @@ final class GraphInterpreter(
       enqueue(connection)
     } else if ((currentState & (InClosed | Pushing | Pulling | OutClosed)) == 0) enqueue(connection)
 
-    if ((currentState & OutClosed) == 0) completeConnection(connection.outOwnerId)
+    if ((currentState & OutClosed) == 0) completeConnection(connection.outOwner.stageId)
   }
 
   private[stream] def fail(connection: Connection, ex: Throwable): Unit = {
@@ -605,7 +600,7 @@ final class GraphInterpreter(
         enqueue(connection)
       }
     }
-    if ((currentState & OutClosed) == 0) completeConnection(connection.outOwnerId)
+    if ((currentState & OutClosed) == 0) completeConnection(connection.outOwner.stageId)
   }
 
   private[stream] def cancel(connection: Connection): Unit = {
@@ -622,7 +617,7 @@ final class GraphInterpreter(
         enqueue(connection)
       }
     }
-    if ((currentState & InClosed) == 0) completeConnection(connection.inOwnerId)
+    if ((currentState & InClosed) == 0) completeConnection(connection.inOwner.stageId)
   }
 
   /**