mio

标准库也缺乏对套接字和连接的细粒度控制，例如设置SO_REUSEADDR。mio库则提供了很多方法来解决这些问题。

依赖

[dependencies]
mio = { version = "0.7.0", features = ["os-poll", "tcp"]}

源码示例

use mio::net::{TcpListener, TcpStream};
use mio::{Events, Interest, Poll, Token};

const SERVER: Token = Token(0);
const CLIENT: Token = Token(1);

fn main() -> std::io::Result<()> {
    let mut poll = Poll::new()?;
    let mut events = Events::with_capacity(128);

    // 创建server端socket
    let addr = "127.0.0.1:8080".parse().unwrap();
    let mut server = TcpListener::bind(addr)?;
    
    // 开始监听该链接
    poll.registry()
        .register(&mut server, SERVER, Interest::READABLE)?;

    // 创建客户端链接到服务端
    let mut client = TcpStream::connect(addr)?;

    // 监听客户端
    poll.registry()
        .register(&mut client, CLIENT, Interest::READABLE | Interest::WRITABLE)?;

    // 启动循环
    loop {
        // 轮训事件
        poll.poll(&mut events, None)?;

        // 处理事件
        let mut cnt = 0;
        for event in events.iter() {
            match event.token() {
                SERVER => {
                    let connection = server.accept();
                    println!("SERVER recv a connection! cnt = {}", cnt);
                    drop(connection);
                }
                CLIENT => {
                    if event.is_writable() {
                        println!("CLIENT write, cnt = {}", cnt);
                    }

                    if event.is_readable() {
                        println!("CLIENT read, cnt = {}", cnt);
                    }
                    
                    return Ok(());
                }

                _ => unreachable!(),
            }
            cnt += 1;
        }
    }
}