RocketMQ producer发送者浅析

public void start() throws MQClientException {
    synchronized (this) {
        switch (this.serviceState) {
            case CREATE_JUST:
                this.serviceState = ServiceState.START_FAILED;
                // If not specified,looking address from name server
                if (null == this.clientConfig.getNamesrvAddr()) {
                    this.mQClientAPIImpl.fetchNameServerAddr();
                }
                // Start request-response channel
                this.mQClientAPIImpl.start();
                // Start various schedule tasks
                this.startScheduledTask();
                // Start pull service
                this.pullMessageService.start();
                // Start rebalance service
                this.rebalanceService.start();
                // Start push service
                this.defaultMQProducer.getDefaultMQProducerImpl().start(false);
                log.info("the client factory [{}] start OK", this.clientId);
                this.serviceState = ServiceState.RUNNING;
                break;
            case START_FAILED:
                throw new MQClientException("The Factory object[" + this.getClientId() + "] has been created before, and failed.", null);
            default:
                break;
        }
    }
}

    public boolean updateTopicRouteInfoFromNameServer(final String topic, boolean isDefault,
        DefaultMQProducer defaultMQProducer) {
        try {
            if (this.lockNamesrv.tryLock(LOCK_TIMEOUT_MILLIS, TimeUnit.MILLISECONDS)) {
                try {
                    TopicRouteData topicRouteData;
                    if (isDefault && defaultMQProducer != null) {
                        // 从nameServer获取topciRouteData
                        topicRouteData = this.mQClientAPIImpl.getDefaultTopicRouteInfoFromNameServer(defaultMQProducer.getCreateTopicKey(),
                            clientConfig.getMqClientApiTimeout());
                        if (topicRouteData != null) {
                            for (QueueData data : topicRouteData.getQueueDatas()) {
                                int queueNums = Math.min(defaultMQProducer.getDefaultTopicQueueNums(), data.getReadQueueNums());
                                data.setReadQueueNums(queueNums);
                                data.setWriteQueueNums(queueNums);
                            }
                        }
                    } else {
                        topicRouteData = this.mQClientAPIImpl.getTopicRouteInfoFromNameServer(topic, clientConfig.getMqClientApiTimeout());
                    }
                    if (topicRouteData != null) {
                        TopicRouteData old = this.topicRouteTable.get(topic);
                        boolean changed = topicRouteData.topicRouteDataChanged(old);
                        if (!changed) {
                            changed = this.isNeedUpdateTopicRouteInfo(topic);
                        } else {
                            log.info("the topic[{}] route info changed, old[{}] ,new[{}]", topic, old, topicRouteData);
                        }
                        if (changed) {
                            for (BrokerData bd : topicRouteData.getBrokerDatas()) {
                                this.brokerAddrTable.put(bd.getBrokerName(), bd.getBrokerAddrs());
                            }
                            // Update endpoint map
                            {
                                ConcurrentMap<MessageQueue, String> mqEndPoints = topicRouteData2EndpointsForStaticTopic(topic, topicRouteData);
                                if (!mqEndPoints.isEmpty()) {
                                    topicEndPointsTable.put(topic, mqEndPoints);
                                }
                            }
                            // Update Pub info
                            {
                                // 生成topicPublishInfo
                                TopicPublishInfo publishInfo = topicRouteData2TopicPublishInfo(topic, topicRouteData);
                                publishInfo.setHaveTopicRouterInfo(true);
                                for (Entry<String, MQProducerInner> entry : this.producerTable.entrySet()) {
                                    MQProducerInner impl = entry.getValue();
                                    if (impl != null) {
                                        // 更新 topicPublishInfo
                                        impl.updateTopicPublishInfo(topic, publishInfo);
                                    }
                                }
                            }
                            // Update sub info
                            if (!consumerTable.isEmpty()) {
                                Set<MessageQueue> subscribeInfo = topicRouteData2TopicSubscribeInfo(topic, topicRouteData);
                                for (Entry<String, MQConsumerInner> entry : this.consumerTable.entrySet()) {
                                    MQConsumerInner impl = entry.getValue();
                                    if (impl != null) {
                                        impl.updateTopicSubscribeInfo(topic, subscribeInfo);
                                    }
                                }
                            }
                            TopicRouteData cloneTopicRouteData = new TopicRouteData(topicRouteData);
                            log.info("topicRouteTable.put. Topic = {}, TopicRouteData[{}]", topic, cloneTopicRouteData);
                            this.topicRouteTable.put(topic, cloneTopicRouteData);
                            return true;
                        }
                    } else {
                        log.warn("updateTopicRouteInfoFromNameServer, getTopicRouteInfoFromNameServer return null, Topic: {}. [{}]", topic, this.clientId);
                    }
                } catch (MQClientException e) {
                    if (!topic.startsWith(MixAll.RETRY_GROUP_TOPIC_PREFIX) && !topic.equals(TopicValidator.AUTO_CREATE_TOPIC_KEY_TOPIC)) {
                        log.warn("updateTopicRouteInfoFromNameServer Exception", e);
                    }
                } catch (RemotingException e) {
                    log.error("updateTopicRouteInfoFromNameServer Exception", e);
                    throw new IllegalStateException(e);
                } finally {
                    this.lockNamesrv.unlock();
                }
            } else {
                log.warn("updateTopicRouteInfoFromNameServer tryLock timeout {}ms. [{}]", LOCK_TIMEOUT_MILLIS, this.clientId);
            }
        } catch (InterruptedException e) {
            log.warn("updateTopicRouteInfoFromNameServer Exception", e);
        }
        return false;
    }