From ccd58c4c08759205ede79920f17d5fee458f398a Mon Sep 17 00:00:00 2001
From: qiuyucheng <qiuyucheng@qq.com>
Date: Wed, 24 Dec 2025 10:02:40 +0800
Subject: [PATCH] [Fix-15886] Fix thread leak in NacosRegistry using
 Double-Checked Locking

---
 .../dubbo/registry/nacos/NacosRegistry.java   | 44 ++++++++++---------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/dubbo-registry/dubbo-registry-nacos/src/main/java/org/apache/dubbo/registry/nacos/NacosRegistry.java b/dubbo-registry/dubbo-registry-nacos/src/main/java/org/apache/dubbo/registry/nacos/NacosRegistry.java
index 3c98e1c3e358..52c9f9668200 100644
--- a/dubbo-registry/dubbo-registry-nacos/src/main/java/org/apache/dubbo/registry/nacos/NacosRegistry.java
+++ b/dubbo-registry/dubbo-registry-nacos/src/main/java/org/apache/dubbo/registry/nacos/NacosRegistry.java
@@ -473,26 +473,30 @@ private boolean isAdminProtocol(URL url) {
 
     private void scheduleServiceNamesLookup(final URL url, final NacosAggregateListener listener) {
         if (scheduledExecutorService == null) {
-            scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
-            scheduledExecutorService.scheduleAtFixedRate(
-                    () -> {
-                        Set<String> serviceNames = getAllServiceNames();
-                        filterData(serviceNames, serviceName -> {
-                            boolean accepted = false;
-                            for (String category : ALL_SUPPORTED_CATEGORIES) {
-                                String prefix = category + SERVICE_NAME_SEPARATOR;
-                                if (serviceName != null && serviceName.startsWith(prefix)) {
-                                    accepted = true;
-                                    break;
-                                }
-                            }
-                            return accepted;
-                        });
-                        doSubscribe(url, listener, serviceNames);
-                    },
-                    LOOKUP_INTERVAL,
-                    LOOKUP_INTERVAL,
-                    TimeUnit.SECONDS);
+            synchronized (this) {
+                if (scheduledExecutorService == null) {
+                    scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
+                    scheduledExecutorService.scheduleAtFixedRate(
+                            () -> {
+                                Set<String> serviceNames = getAllServiceNames();
+                                filterData(serviceNames, serviceName -> {
+                                    boolean accepted = false;
+                                    for (String category : ALL_SUPPORTED_CATEGORIES) {
+                                        String prefix = category + SERVICE_NAME_SEPARATOR;
+                                        if (serviceName != null && serviceName.startsWith(prefix)) {
+                                            accepted = true;
+                                            break;
+                                        }
+                                    }
+                                    return accepted;
+                                });
+                                doSubscribe(url, listener, serviceNames);
+                            },
+                            LOOKUP_INTERVAL,
+                            LOOKUP_INTERVAL,
+                            TimeUnit.SECONDS);
+                }
+            }
         }
     }