Concurrency security issues

 public List<RegisterBrokerResult> registerBrokerAll(
        final String clusterName,
        final String brokerAddr,
        final String brokerName,
        final long brokerId,
        final String haServerAddr,
        final TopicConfigSerializeWrapper topicConfigWrapper,
        final List<String> filterServerList,
        final boolean oneway,
        final int timeoutMills,
        final boolean compressed) {

        // 初始化一个List，存放每个NameServer注册结果的
        // 多线程 会有并发问题吧
        final List<RegisterBrokerResult> registerBrokerResultList = Lists.newArrayList();

        // 获取 NameServer 地址列表
        List<String> nameServerAddressList =
                this.remotingClient.getNameServerAddressList();
        if (nameServerAddressList != null && nameServerAddressList.size() > 0) {

            // 构建请求头，在请求头里面放很多的信息，比如说 BrokerId 和 BrokerName
            final RegisterBrokerRequestHeader requestHeader = new RegisterBrokerRequestHeader();
            requestHeader.setBrokerAddr(brokerAddr);
            requestHeader.setBrokerId(brokerId);
            requestHeader.setBrokerName(brokerName);
            requestHeader.setClusterName(clusterName);
            requestHeader.setHaServerAddr(haServerAddr);
            requestHeader.setCompressed(compressed);

            // 构建请求体，包含一些配置
            RegisterBrokerBody requestBody = new RegisterBrokerBody();
            requestBody.setTopicConfigSerializeWrapper(topicConfigWrapper);
            requestBody.setFilterServerList(filterServerList);
            final byte[] body = requestBody.encode(compressed);
            final int bodyCrc32 = UtilAll.crc32(body);
            requestHeader.setBodyCrc32(bodyCrc32);
            // 使用CountDownLatch同步计数器，保证注册完全部的 NameServer之后才往下走，
            // 执行其他逻辑
            final CountDownLatch countDownLatch = new CountDownLatch(nameServerAddressList.size());
            // 遍历NameServer 地址列表，使用线程池去注册
            for (final String namesrvAddr : nameServerAddressList) {
                brokerOuterExecutor.execute(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            // 调用 registerBroker 真正执行注册
                            RegisterBrokerResult result = registerBroker(namesrvAddr,oneway, timeoutMills,requestHeader,body);
                            **if (result != null) {
                                // 注册成功结果放到一个List里去
                                registerBrokerResultList.add(result);
                            }**

                            log.info("register broker[{}]to name server {} OK", brokerId, namesrvAddr);
                        } catch (Exception e) {
                            log.warn("registerBroker Exception, {}", namesrvAddr, e);
                        } finally {
                            // 注册完，执行 countDownLatch.countDown(); 同步计数器 -1
                            countDownLatch.countDown();
                        }
                    }
                });
            }

            try {
                // 等待所有 NameServer 都注册完，才返回注册结果
                countDownLatch.await(timeoutMills, TimeUnit.MILLISECONDS);
            } catch (InterruptedException e) {
            }
        }

        return registerBrokerResultList;
    }

final List<RegisterBrokerResult> registerBrokerResultList = Lists.newArrayList(); Does this code have concurrency security issues? I reproduced the code, conducted more than 100 experiments, and found that there is indeed a concurrency security problem.

and this is my original code: https://github.com/androidkaifa1/RocketMQTEST

[francisoliverlee]

registerBrokerResultList should be thread-safe, nice of u to fix it

[CodeDeveloperC]

@francisoliverlee Thanks for your answer. I have fixed it. and the link is https://github.com/apache/rocketmq/pull/2203

Here is My changes.Thank you!