added hasQueued() to avoid defferals.

Author: i-make-robots

src/main/java/com/marginallyclever/nodegraphcore/ThreadPoolScheduler.java

@@ -1,15 +1,16 @@
 package com.marginallyclever.nodegraphcore;
 
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.concurrent.TimeUnit;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.util.concurrent.*;
 import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  * A scheduler that runs a graph of nodes using a thread pool.
  */
 public class ThreadPoolScheduler {
+    private static final Logger logger = LoggerFactory.getLogger(ThreadPoolScheduler.class);
     private final ExecutorService threadPool = Executors.newVirtualThreadPerTaskExecutor();
     private final BlockingQueue<Node> readyNodes = new LinkedBlockingQueue<>();
     private final AtomicInteger activeTasks = new AtomicInteger(0);
@@ -22,10 +23,12 @@ public ThreadPoolScheduler() {}
      */
     public void submit(Node node) {
         if(readyNodes.contains(node)) {
-            // move node to the end of the queue
+            logger.debug("defer {}", node.getName());
+            // move node to the tail of the queue
             readyNodes.remove(node);
             readyNodes.add(node);
         } else {
+            logger.debug("add {}", node.getName());
             readyNodes.add(node); // Add the node to the ready queue
             activeTasks.incrementAndGet(); // Increment task count
         }
@@ -55,19 +58,21 @@ public void update() {
         if (node == null) return;
 
         threadPool.submit(() -> {
+            logger.debug("start {}", node.getName());
             try {
                 node.update();
                 node.updateBounds();
                 node.setInputsClean();
                 for(Node downstreamNode : node.getDownstreamNodes()) {
-                    if(downstreamNode.isDirty()) {
-                        submit(downstreamNode); // Submit downstream nodes
+                    if(downstreamNode.isDirty() && !hasQueued(downstreamNode)) {
+                        submit(downstreamNode);  // Submit downstream nodes
                     }
                 }
             } catch (Exception e) {
                 System.err.println("Error in node execution: " + e.getMessage());
                 e.printStackTrace();
             } finally {
+                logger.debug("end {}", node.getName());
                 activeTasks.decrementAndGet(); // Mark this task as completed
             }
         });
@@ -84,4 +89,12 @@ public void shutdown(long timeoutSeconds) {
             Thread.currentThread().interrupt();
         }
     }
+
+    /**
+     * @param n the {@link Node} to check
+     * @return true if the node is in the ready queue
+     */
+    public boolean hasQueued(Node n) {
+        return readyNodes.contains(n);
+    }
 }