平台工具MicroService技术框架Netty

Netty服务端启动流程

Catalogue
  1. 两个线程组
  2. 引导程序

两个线程组

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EventLoopGroup boosGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();

EventLoopGroup的定义

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public class NioEventLoopGroup extends MultithreadEventLoopGroup{
	    /**
     * Sets the percentage of the desired amount of time spent for I/O in the child event loops.  The default value is
     * {@code 50}, which means the event loop will try to spend the same amount of time for I/O as for non-I/O tasks.
     */
    public void setIoRatio(int ioRatio) {
        for (EventExecutor e: children()) {
            ((NioEventLoop) e).setIoRatio(ioRatio);
        }
    }
    /**
     * Replaces the current {@link Selector}s of the child event loops with newly created {@link Selector}s to work
     * around the  infamous epoll 100% CPU bug.
     */
    public void rebuildSelectors() {
        for (EventExecutor e: children()) {
            ((NioEventLoop) e).rebuildSelector();
        }
    }

    @Override
    protected EventExecutor newChild(ThreadFactory threadFactory, Object... args) throws Exception {
        return new NioEventLoop(this, threadFactory, (SelectorProvider) args[0],
            ((SelectStrategyFactory) args[1]).newSelectStrategy(), (RejectedExecutionHandler) args[2]);
    }
}

专门用于处理网络的事件

一个用于处理接受客户端的连接，一个用于进行 SocketChannel 的网络读取。

boos这个EventLoopGroup作为一个acceptor负责接收来自客户端的请求，然后分发给worker这个EventLoopGroup来处理所有的事件event和channel的IO。

引导程序

ServerBootstrap. 启动NIO服务的辅助启动类.

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ServerBootstrap b = new ServerBootstrap()
        .group(boosGroup, workerGroup)
        .channel(NioServerSocketChannel.class)
        .option(ChannelOption.SO_BACKLOG, 1012)
        .childHandler(new ChildChannelHandler());

ChannelFuture f = b.bind(port).sync();     // 绑定端口
f.channel().closeFuture().sync();// 等待服务器端监听端口关闭
    1. group方法绑定了两个NIO线程组
    1. 绑定处理消息的Handler. handler处理流程和管理流程-TODO