如何在mio中复制POLLPRI的轮询行为？

use mio::{Events, Poll, PollOpt, Ready, Token};
use std::io::{Read, Write};
use std::net::TcpStream;

fn main() {
    // 创建EventLoop实例
    let mut event_loop = mio::EventLoop::new().unwrap();
    
    // 创建TcpStream并连接服务器
    let mut stream = TcpStream::connect("127.0.0.1:8080").unwrap();
    
    // 注册POLLPRI事件
    event_loop.register(&stream,
                        Token(0),
                        Ready::readable() | Ready::pri(),
                        PollOpt::edge()).unwrap();
    
    // 启动事件循环
    event_loop.run(&mut MyHandler { stream: &mut stream }).unwrap();
}

struct MyHandler<'a> {
    stream: &'a mut TcpStream,
}

impl<'a> mio::Handler for MyHandler<'a> {
    type Timeout = ();
    type Message = ();

    fn ready(&mut self,
             event_loop: &mut mio::EventLoop<MyHandler>,
             token: mio::Token,
             events: mio::Ready) {
        if events.is_readable() || events.is_pri() {
            // 处理POLLPRI事件
            let mut buf = [0; 1024];
            match self.stream.read(&mut buf) {
                Ok(0) => event_loop.shutdown(),
                Ok(n) => {
                    // 读取紧急数据
                    let data = &buf[..n];
                    // 处理紧急数据
                    // ...
                }
                Err(_) => event_loop.shutdown(),
            }
        }
    }
}