java重试机制代码设计 RPC原理及实例分析(10)

在启动Listener线程时，服务端会一直等待客户端的连接，下面贴出Server.Listener类的run()方法：

 public void run() {
     ??????
      while (running) {
        SelectionKey key = null;
        try {
          selector.select();
          Iterator<SelectionKey> iter = selector.selectedKeys().iterator();
          while (iter.hasNext()) {
            key = iter.next();
            iter.remove();
            try {
              if (key.isValid()) {
                if (key.isAcceptable())
                  doAccept(key);     //具体的连接方法
              }
            } catch (IOException e) {
            }
            key = null;
          }
        } catch (OutOfMemoryError e) {
       ??????         
    }

下面贴出Server.Listener类中doAccept()方法中的关键源码吧：

    void doAccept(SelectionKey key) throws IOException,  OutOfMemoryError {
      Connection c = null;
      ServerSocketChannel server = (ServerSocketChannel) key.channel();
      SocketChannel channel;
      while ((channel = server.accept()) != null) { //建立连接
        channel.configureBlocking(false);
        channel.socket().setTcpNoDelay(tcpNoDelay);
        Reader reader = getReader();  //从readers池中获得一个reader
        try {
          reader.startAdd(); // 激活readSelector，设置adding为true
          SelectionKey readKey = reader.registerChannel(channel);//将读事件设置成兴趣事件
          c = new Connection(readKey, channel, System.currentTimeMillis());//创建一个连接对象
          readKey.attach(c);   //将connection对象注入readKey
          synchronized (connectionList) {
            connectionList.add(numConnections, c);
            numConnections++;
          }
        ?????? 
        } finally {
//设置adding为false，采用notify()唤醒一个reader,其实代码十三中启动的每个reader都使
//用了wait()方法等待。因篇幅有限，就不贴出源码了。
          reader.finishAdd();
        }
      }
    }

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