有没有办法检查连接是否已关闭然后完成线程？

Question

使用类似于 this example 的代码，连接永远持续下去，因为无限循环永远不会停止。我对其进行了一些修改，以便阅读不会阻塞线程：

use std::net::{TcpListener, TcpStream};
use std::io::{BufRead, BufReader};
use std::thread;

fn main() {
    let listener = TcpListener::bind("127.0.0.1:4444").unwrap();
    println!("Server is running on 127.0.0.1:4444 ...");

    for stream in listener.incoming() {
        let stream = stream.unwrap();
        stream
            .set_nonblocking(true)
            .expect("Failed to set stream as nonblocking");
        thread::spawn(move || handle_client(stream));
    }
}

fn handle_client(stream: TcpStream) {
    let mut stream = BufReader::new(stream);
    println!("New client logged");

    loop {
        let mut recv_buffer = String::new();
        println!("Before reading");
        let recv_data_size = stream
            .read_line(&mut recv_buffer)
            .expect("Error when reading line");

        if recv_data_size > 0 {
            println!("{}", recv_buffer);
        }
    }
}

客户端很简单，连接然后发送Hello!到服务器：

use std::io::prelude::*;
use std::net::TcpStream;

fn main() {
    let mut stream = TcpStream::connect("127.0.0.1:4444").unwrap();
    let _ = stream.write("Hello!".as_bytes());
}

当客户端发送它的字符串并且断开连接时，服务器进入无限循环并无限期地打印Before reading。它永远不知道什么时候关闭连接，即使客户端很久以前就结束了它。

Rust 有没有办法检查远程连接是否已关闭（如果可能而无需设置超时），然后正确完成它所在的线程运行？

Answer 1

来自 read_line 的文档：

An empty buffer returned indicates that the stream has reached EOF.

所以你可以这样做：

fn handle_client(stream: TcpStream) {
    let mut stream = BufReader::new(stream);
    println!("New client logged");

    loop {
        let mut recv_buffer = String::new();
        println!("Before reading");
        let recv_data_size = stream
            .read_line(&mut recv_buffer)
            .expect("Error when reading line");

        if recv_data_size > 0 {
            println!("{}", recv_buffer);
        } else {
            // stream has reached EOF
            break;
        }
    }
}

有没有办法检查连接是否已关闭然后完成线程？

Is there a way to check if a connection has been closed then finish the thread?

multithreading

sockets

networking

rust

tcplistener