From f9b912baf02eb2dad76e3ab4dfb00f3eeeb8aff7 Mon Sep 17 00:00:00 2001
From: Yashashree Chopada <yashashreechopada@gmail.com>
Date: Thu, 22 Aug 2024 00:53:41 +0530
Subject: [PATCH] ARTEMIS-4972 Use Lock in start() for Binding Variables

---
 .../core/server/group/impl/LocalGroupingHandler.java | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/artemis-server/src/main/java/org/apache/activemq/artemis/core/server/group/impl/LocalGroupingHandler.java b/artemis-server/src/main/java/org/apache/activemq/artemis/core/server/group/impl/LocalGroupingHandler.java
index d34f587dd8..6fbdbbb508 100644
--- a/artemis-server/src/main/java/org/apache/activemq/artemis/core/server/group/impl/LocalGroupingHandler.java
+++ b/artemis-server/src/main/java/org/apache/activemq/artemis/core/server/group/impl/LocalGroupingHandler.java
@@ -322,9 +322,15 @@ public final class LocalGroupingHandler extends GroupHandlingAbstract {
       if (started)
          return;
 
-      if (expectedBindings == null) {
-         // just in case the component is restarted
-         expectedBindings = new LinkedList<>();
+      lock.lock();
+
+      try {
+         if (expectedBindings == null) {
+            // just in case the component is restarted
+            expectedBindings = new LinkedList<>();
+         }
+      } finally {
+         lock.unlock();
       }
 
       if (reaperPeriod > 0 && groupTimeout > 0) {