Replace RunnableChain in DeferredUpdateManager with List - Bug 281327

In the class org.eclipse.draw2d.DeferredUpdateManager, Runnables are
queued using a special inner class RunnableChain which basically
produces a linked list of Runnables. When run is called on the head of
the linked list, first run of its next element is called an then run on
the runnable of the element itself.

This produces very large stacks, for each element in the list, a new
stack frame is created. Instead of the RunnableChain construct, a simple
ArrayList can be used as queue which will be faster and use less
memory.

Author: ptziegler

org.eclipse.draw2d/src/org/eclipse/draw2d/DeferredUpdateManager.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2024 IBM Corporation and others.
+ * Copyright (c) 2000, 2025 IBM Corporation and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License 2.0 which is available at
@@ -57,26 +57,9 @@ public void run() {
 
 	private boolean updating;
 	private boolean validating;
-	private RunnableChain afterUpdate;
+	private List<Runnable> afterUpdate = new ArrayList<>();
 	private int refreshRate = -1;
 
-	private static class RunnableChain {
-		RunnableChain next;
-		Runnable run;
-
-		RunnableChain(Runnable run, RunnableChain next) {
-			this.run = run;
-			this.next = next;
-		}
-
-		void run() {
-			if (next != null) {
-				next.run();
-			}
-			run.run();
-		}
-	}
-
 	/**
 	 * Empty constructor.
 	 */
@@ -195,11 +178,11 @@ public synchronized void performUpdate() {
 			performValidation();
 			updateQueued = false;
 			repairDamage();
-			if (afterUpdate != null) {
-				RunnableChain chain = afterUpdate;
-				afterUpdate = null;
-				chain.run(); // chain may queue additional Runnable.
-				if (afterUpdate != null) {
+			if (!afterUpdate.isEmpty()) {
+				List<Runnable> chain = afterUpdate;
+				afterUpdate = new ArrayList<>();
+				chain.forEach(Runnable::run); // chain may queue additional Runnable.
+				if (!afterUpdate.isEmpty()) {
 					queueWork();
 				}
 			}
@@ -330,7 +313,7 @@ protected void repairDamage() {
 	 */
 	@Override
 	public synchronized void runWithUpdate(Runnable runnable) {
-		afterUpdate = new RunnableChain(runnable, afterUpdate);
+		afterUpdate.add(runnable);
 		if (!updating) {
 			queueWork();
 		}