src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.graph/src/org/graalvm/compiler/graph/Graph.java

*** 512,563 ****
          ZERO_USAGES,
  
          /**
           * A node was added to a graph.
           */
!         NODE_ADDED;
      }
  
      /**
       * Client interested in one or more node related events.
       */
!     public interface NodeEventListener {
  
          /**
!          * Default handler for events.
           *
           * @param e an event
           * @param node the node related to {@code e}
           */
!         default void event(NodeEvent e, Node node) {
          }
  
          /**
!          * Notifies this listener of a change in a node's inputs.
           *
           * @param node a node who has had one of its inputs changed
           */
!         default void inputChanged(Node node) {
!             event(NodeEvent.INPUT_CHANGED, node);
          }
  
          /**
           * Notifies this listener of a node becoming unused.
           *
           * @param node a node whose {@link Node#usages()} just became empty
           */
!         default void usagesDroppedToZero(Node node) {
!             event(NodeEvent.ZERO_USAGES, node);
          }
  
          /**
           * Notifies this listener of an added node.
           *
           * @param node a node that was just added to the graph
           */
!         default void nodeAdded(Node node) {
!             event(NodeEvent.NODE_ADDED, node);
          }
      }
  
      /**
       * Registers a given {@link NodeEventListener} with the enclosing graph until this object is
--- 512,600 ----
          ZERO_USAGES,
  
          /**
           * A node was added to a graph.
           */
!         NODE_ADDED,
! 
!         /**
!          * A node was removed from the graph.
!          */
!         NODE_REMOVED;
      }
  
      /**
       * Client interested in one or more node related events.
       */
!     public abstract static class NodeEventListener {
  
          /**
!          * A method called when a change event occurs.
!          *
!          * This method dispatches the event to user-defined triggers. The methods that change the
!          * graph (typically in Graph and Node) must call this method to dispatch the event.
           *
           * @param e an event
           * @param node the node related to {@code e}
           */
!         final void event(NodeEvent e, Node node) {
!             switch (e) {
!                 case INPUT_CHANGED:
!                     inputChanged(node);
!                     break;
!                 case ZERO_USAGES:
!                     usagesDroppedToZero(node);
!                     break;
!                 case NODE_ADDED:
!                     nodeAdded(node);
!                     break;
!                 case NODE_REMOVED:
!                     nodeRemoved(node);
!                     break;
!             }
!             changed(e, node);
          }
  
          /**
!          * Notifies this listener about any change event in the graph.
!          *
!          * @param e an event
!          * @param node the node related to {@code e}
!          */
!         public void changed(NodeEvent e, Node node) {
!         }
! 
!         /**
!          * Notifies this listener about a change in a node's inputs.
           *
           * @param node a node who has had one of its inputs changed
           */
!         public void inputChanged(Node node) {
          }
  
          /**
           * Notifies this listener of a node becoming unused.
           *
           * @param node a node whose {@link Node#usages()} just became empty
           */
!         public void usagesDroppedToZero(Node node) {
          }
  
          /**
           * Notifies this listener of an added node.
           *
           * @param node a node that was just added to the graph
           */
!         public void nodeAdded(Node node) {
!         }
! 
!         /**
!          * Notifies this listener of a removed node.
!          *
!          * @param node
!          */
!         public void nodeRemoved(Node node) {
          }
      }
  
      /**
       * Registers a given {@link NodeEventListener} with the enclosing graph until this object is
*** 581,591 ****
                  nodeEventListener = null;
              }
          }
      }
  
!     private static class ChainedNodeEventListener implements NodeEventListener {
  
          NodeEventListener head;
          NodeEventListener next;
  
          ChainedNodeEventListener(NodeEventListener head, NodeEventListener next) {
--- 618,628 ----
                  nodeEventListener = null;
              }
          }
      }
  
!     private static class ChainedNodeEventListener extends NodeEventListener {
  
          NodeEventListener head;
          NodeEventListener next;
  
          ChainedNodeEventListener(NodeEventListener head, NodeEventListener next) {
*** 593,616 ****
              this.next = next;
          }
  
          @Override
          public void nodeAdded(Node node) {
!             head.nodeAdded(node);
!             next.nodeAdded(node);
          }
  
          @Override
          public void inputChanged(Node node) {
!             head.inputChanged(node);
!             next.inputChanged(node);
          }
  
          @Override
          public void usagesDroppedToZero(Node node) {
!             head.usagesDroppedToZero(node);
!             next.usagesDroppedToZero(node);
          }
      }
  
      /**
       * Registers a given {@link NodeEventListener} with this graph. This should be used in
--- 630,665 ----
              this.next = next;
          }
  
          @Override
          public void nodeAdded(Node node) {
!             head.event(NodeEvent.NODE_ADDED, node);
!             next.event(NodeEvent.NODE_ADDED, node);
          }
  
          @Override
          public void inputChanged(Node node) {
!             head.event(NodeEvent.INPUT_CHANGED, node);
!             next.event(NodeEvent.INPUT_CHANGED, node);
          }
  
          @Override
          public void usagesDroppedToZero(Node node) {
!             head.event(NodeEvent.ZERO_USAGES, node);
!             next.event(NodeEvent.ZERO_USAGES, node);
!         }
! 
!         @Override
!         public void nodeRemoved(Node node) {
!             head.event(NodeEvent.NODE_REMOVED, node);
!             next.event(NodeEvent.NODE_REMOVED, node);
!         }
! 
!         @Override
!         public void changed(NodeEvent e, Node node) {
!             head.event(e, node);
!             next.event(e, node);
          }
      }
  
      /**
       * Registers a given {@link NodeEventListener} with this graph. This should be used in
*** 1021,1031 ****
          seenNodeSourcePosition = seenNodeSourcePosition || node.getNodeSourcePosition() != null;
  
          updateNodeCaches(node);
  
          if (nodeEventListener != null) {
!             nodeEventListener.nodeAdded(node);
          }
          afterRegister(node);
      }
  
      private void grow() {
--- 1070,1080 ----
          seenNodeSourcePosition = seenNodeSourcePosition || node.getNodeSourcePosition() != null;
  
          updateNodeCaches(node);
  
          if (nodeEventListener != null) {
!             nodeEventListener.event(NodeEvent.NODE_ADDED, node);
          }
          afterRegister(node);
      }
  
      private void grow() {
*** 1083,1092 ****
--- 1132,1145 ----
              removeNodeFromCache(node);
          }
          nodes[node.id] = null;
          nodesDeletedSinceLastCompression++;
  
+         if (nodeEventListener != null) {
+             nodeEventListener.event(NodeEvent.NODE_ADDED, node);
+         }
+ 
          // nodes aren't removed from the type cache here - they will be removed during iteration
      }
  
      public boolean verify() {
          if (Options.VerifyGraalGraphs.getValue(options)) {