From 89e5898a59f64d0468d5d43215d22764c73ff081 Mon Sep 17 00:00:00 2001
From: Zhanhui Li <lizhanhui@apache.org>
Date: Thu, 29 Dec 2016 14:58:59 +0800
Subject: [PATCH] Fix data race issue

---
 .../org/apache/rocketmq/client/impl/MQAdminImpl.java  | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/client/src/main/java/org/apache/rocketmq/client/impl/MQAdminImpl.java b/client/src/main/java/org/apache/rocketmq/client/impl/MQAdminImpl.java
index fb948b7796b..8267336797c 100644
--- a/client/src/main/java/org/apache/rocketmq/client/impl/MQAdminImpl.java
+++ b/client/src/main/java/org/apache/rocketmq/client/impl/MQAdminImpl.java
@@ -23,6 +23,9 @@
 import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
 import org.apache.rocketmq.client.QueryResult;
 import org.apache.rocketmq.client.exception.MQBrokerException;
 import org.apache.rocketmq.client.exception.MQClientException;
@@ -284,6 +287,7 @@ protected QueryResult queryMessage(String topic, String key, int maxNum, long be
 
             if (!brokerAddrs.isEmpty()) {
                 final CountDownLatch countDownLatch = new CountDownLatch(brokerAddrs.size());
+                final ReadWriteLock lock = new ReentrantReadWriteLock();
                 final List<QueryResult> queryResultList = new LinkedList<QueryResult>();
 
                 for (String addr : brokerAddrs) {
@@ -318,7 +322,12 @@ public void operationComplete(ResponseFuture responseFuture) {
                                                         MessageDecoder.decodes(ByteBuffer.wrap(response.getBody()), true);
 
                                                     QueryResult qr = new QueryResult(responseHeader.getIndexLastUpdateTimestamp(), wrappers);
-                                                    queryResultList.add(qr);
+                                                    try {
+                                                        lock.writeLock().lock();
+                                                        queryResultList.add(qr);
+                                                    } finally {
+                                                        lock.writeLock().unlock();
+                                                    }
                                                     break;
                                                 }
                                                 default: