全站最硬核 百万字强肝RocketMq源码 火热更新中~（二十三）

进来首先，如果channel不为空，则获取读锁，这里注意RouteInfoManager内部是声明了读写锁的：

private final ReadWriteLock lock = new ReentrantReadWriteLock();

获取锁成功后，接下来从brokerLiveTable（在线的broker表）中遍历出value（BrokerLiveInfo）的channel为目标channel的key作为brokerAddrFound。也就是说第一个if，就是从brokerLiveTable中取出一个key：brokerAddrFound（broker的地址）

整个方法的主要部分都集中在对这个取出的key：brokerAddrFound的处理上。虽然代码很长，但整体逻辑并不复杂，都是删除key为brokerAddrFound的各种表中的元素：（合法化处理还有异常捕获这里就不分析了）

this.lock.writeLock().lockInterruptibly();
this.brokerLiveTable.remove(brokerAddrFound);
this.filterServerTable.remove(brokerAddrFound);

获取读锁（增删改都是取读锁），先从brokerLiveTable，filterServerTable中移除key为broker地址的元素。这也符合该方法的逻辑：channelDestory。

while (itBrokerAddrTable.hasNext() && (null == brokerNameFound)) {
    BrokerData brokerData = itBrokerAddrTable.next().getValue();

    Iterator> it = brokerData.getBrokerAddrs().entrySet().iterator();
    while (it.hasNext()) {
        Entry entry = it.next();
        Long brokerId = entry.getKey();
        String brokerAddr = entry.getValue();
        if (brokerAddr.equals(brokerAddrFound)) {
            brokerNameFound = brokerData.getBrokerName();
            it.remove();
            log.info("remove brokerAddr[{}, {}] from brokerAddrTable, because channel destroyed",
                brokerId, brokerAddr);
            break;
        }
    }

    if (brokerData.getBrokerAddrs().isEmpty()) {
        removeBrokerName = true;
        itBrokerAddrTable.remove();
        log.info("remove brokerName[{}] from brokerAddrTable, because channel destroyed",
            brokerData.getBrokerName());
    }
}

从brokerData中移除

if (brokerNameFound != null && removeBrokerName) {
    Iterator>> it = this.clusterAddrTable.entrySet().iterator();
    while (it.hasNext()) {
        Entry> entry = it.next();
        String clusterName = entry.getKey();
        Set brokerNames = entry.getValue();
        boolean removed = brokerNames.remove(brokerNameFound);
        if (removed) {
            log.info("remove brokerName[{}], clusterName[{}] from clusterAddrTable, because channel destroyed",
                brokerNameFound, clusterName);

            if (brokerNames.isEmpty()) {
                log.info("remove the clusterName[{}] from clusterAddrTable, because channel destroyed and no broker in this cluster",
                    clusterName);
                it.remove();
            }

            break;
        }
    }
}