netty5源码分析(3)--学习笔记

本文记录ServerBootstrap.bind(PORT)的过程

最先做的ChannelFuture regFuture = initAndRegister();

final ChannelFuture initAndRegister() {
        final Channel channel = channelFactory().newChannel();
        try {
            init(channel);
        } catch (Throwable t) {
            channel.unsafe().closeForcibly();
            // as the Channel is not registered yet we need to force the usage of the GlobalEventExecutor
            return new DefaultChannelPromise(channel, GlobalEventExecutor.INSTANCE).setFailure(t);
        }

...

channel是初始化NioServerSocketChannel对象

init(NioServerSocketChannel对象)

初始化的工作有创建DefaultChannelHandlerContext,DefaultChannelPipeline,DefaultServerSocketChannelConfig 把设置的ChannelOption添加到DefaultServerSocketChannelConfig,最后在channelPipeline中添加ServerBootstrapAcceptor,

初始化过程出错的处理

        try {
            init(channel);
        } catch (Throwable t) {
            channel.unsafe().closeForcibly();
            // as the Channel is not registered yet we need to force the usage of the GlobalEventExecutor
            return new DefaultChannelPromise(channel, GlobalEventExecutor.INSTANCE).setFailure(t);
        }

channel.unsafe()返回NioMessageUnsafe,最终调用

    @Override
    protected void doClose() throws Exception {
        javaChannel().close();
    }

关闭ServerSocketChannel通道,返回一个 result = new CauseHolder(cause)的DefaultChannelPromise出入的Executor为GlobalEventExecutor单例模式

初始化NioServerSocketChannel对象后,下一步把channel注册到NioEventLoopGroup(主)

    @Override
    public ChannelFuture register(Channel channel) {
        return next().register(channel);
    }

next()为chooser数组里选个NioEventLoop对象，也就是NioEventLoop的register(channel);

    @Override
    public ChannelFuture register(Channel channel) {
        return register(channel, new DefaultChannelPromise(channel, this));
    }

此处产生了DefaultChannelPromise

@Override
    public ChannelFuture register(Channel channel) {
        return register(channel, new DefaultChannelPromise(channel, this));
    }

    @Override
    public ChannelFuture register(final Channel channel, final ChannelPromise promise) {
        if (channel == null) {
            throw new NullPointerException("channel");
        }
        if (promise == null) {
            throw new NullPointerException("promise");
        }

        channel.unsafe().register(this, promise);
        return promise;
    }

channel.unsafe()就是NioServerSocketChannel的newUnsafe方法得到NioMessageUnsafe

@Override
    protected AbstractNioUnsafe newUnsafe() {
        return new NioMessageUnsafe();
    }

AbstractBootstrap接着把NioServerSocketChannel注册到EventLoop上

        ChannelFuture regFuture = group().register(channel);
        if (regFuture.cause() != null) {
            if (channel.isRegistered()) {
                channel.close();
            } else {
                channel.unsafe().closeForcibly();
            }
        }

由EventLoop的父类SingleThreadEventLoop调用 channel.unsafe().register(this, promise);注册,promise是在此处new出new DefaultChannelPromise(channel, this)；EventLoop和NioSocketChannelChannel构建到Promise

NioMessageUnsafe 注册 promise和EventLoop下一文在看

netty5源码分析(3)--学习笔记

猜你喜欢