Netty分布式server启动流程Nio创建源码分析

//创建boss和worker线程(1)
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
//创建ServerBootstrap(2)
ServerBootstrap b = new ServerBootstrap();
//初始化boss和work线程化两个线程(3)
b.group(bossGroup, workerGroup)
        //声明NioServerSocketChannel(4)
        .channel(NioServerSocketChannel.class)
        //初始化客户端Handler(5)
        .childHandler(new ChannelInitializer<SocketChannel>() {
            @Override
            public void initChannel(SocketChannel ch) {
                ch.pipeline().addLast(new StringDecoder());
                ch.pipeline().addLast(new StringEncoder());
                ch.pipeline().addLast(new ServerHandler());
            }
        });
//绑定端口(6)
ChannelFuture f = b.bind(8888).sync();
f.channel().closeFuture().sync();

ChannelFuture f = b.bind(8888).sync();

public ChannelFuture bind(int inetPort) {
    return bind(new InetSocketAddress(inetPort));
}

public ChannelFuture bind(SocketAddress localAddress) {
    validate();
    return doBind(localAddress);
}

private ChannelFuture doBind(final SocketAddress localAddress) {
    //初始化并注册(1)
    final ChannelFuture regFuture = initAndRegister();
    //获得channel(2)
    final Channel channel = regFuture.channel();
    if (regFuture.cause() != null) {
        return regFuture;
    }
    if (regFuture.isDone()) {
        ChannelPromise promise = channel.newPromise();
        //绑定(3) 
        doBind0(regFuture, channel, localAddress, promise);
        return promise;
    } else {
        //去除非关键代码
        return promise;
    }
}

final ChannelFuture regFuture = initAndRegister();

final ChannelFuture initAndRegister() {
    Channel channel = null;
    try {
        //创建channel
        channel = channelFactory.newChannel();
        init(channel);
    } catch (Throwable t) {
        //忽略非关键代码
    }
    ChannelFuture regFuture = config().group().register(channel);
    //忽略非关键代码
    return regFuture;
}

channel = channelFactory.newChannel();

public B channelFactory(ChannelFactory<? extends C> channelFactory) {
    this.channelFactory = channelFactory;
    return (B) this;
}

public B channel(Class<? extends C> channelClass) {
    return channelFactory(new ReflectiveChannelFactory<C>(channelClass));
}

@Override
public T newChannel() {
    try { 
        return clazz.newInstance();
    } catch (Throwable t) {
        throw new ChannelException("Unable to create Channel from class " + clazz, t);
    }
}

public NioServerSocketChannel() {
    this(newSocket(DEFAULT_SELECTOR_PROVIDER));
}

private static final SelectorProvider DEFAULT_SELECTOR_PROVIDER = SelectorProvider.provider();

private static ServerSocketChannel newSocket(SelectorProvider provider) {
    return provider.openServerSocketChannel();
}

public NioServerSocketChannel(ServerSocketChannel channel) {
    super(null, channel, SelectionKey.OP_ACCEPT);
    config = new NioServerSocketChannelConfig(this, javaChannel().socket());
}

protected AbstractNioMessageChannel(Channel parent, SelectableChannel ch, int readInterestOp) {
    super(parent, ch, readInterestOp);
}

protected AbstractNiochannel(Channel parent, SelectableChannel ch, int readInterestOp) {
    super(parent);
    //保存channel
    this.ch = ch;
    //绑定事件
    this.readInterestOp = readInterestOp;
    try {
        //设置为非阻塞
        ch.configureBlocking(false);
    } catch (IOException e) {
        //去掉非关键代码
    }
}

this.ch = ch;

ch.configureBlocking(false);

protected AbstractChannel(Channel parent) {
    this.parent = parent;
    id = newId();
    unsafe = newUnsafe();
    pipeline = newChannelPipeline();
}

unsafe = newUnsafe();
pipeline = newChannelPipeline();