Crate mio

A fast, low-level IO library for Rust focusing on non-blocking APIs, event notification, and other useful utilities for building high performance IO apps.

Goals

• Fast - minimal overhead over the equivalent OS facilities (epoll, kqueue, etc...)
• Zero allocations
• A scalable readiness-based API, similar to epoll on Linux
• Design to allow for stack allocated buffers when possible (avoid double buffering).
• Provide utilities such as a timers, a notification channel, buffer abstractions, and a slab.

Usage

Using mio starts by creating an EventLoop, which handles receiving events from the OS and dispatching them to a supplied Handler.

Example

use mio::*;
use mio::tcp::{TcpListener, TcpStream};

// Setup some tokens to allow us to identify which event is
// for which socket.
const SERVER: Token = Token(0);
const CLIENT: Token = Token(1);

let addr = "127.0.0.1:13265".parse().unwrap();

// Setup the server socket
let server = TcpListener::bind(&addr).unwrap();

// Create an event loop
let mut event_loop = EventLoop::new().unwrap();

// Start listening for incoming connections
event_loop.register(&server, SERVER, EventSet::readable(),
                    PollOpt::edge()).unwrap();

// Setup the client socket
let sock = TcpStream::connect(&addr).unwrap();

// Register the socket
event_loop.register(&sock, CLIENT, EventSet::readable(),
                    PollOpt::edge()).unwrap();

// Define a handler to process the events
struct MyHandler(TcpListener);

impl Handler for MyHandler {
    type Timeout = ();
    type Message = ();

    fn ready(&mut self, event_loop: &mut EventLoop<MyHandler>, token: Token, _: EventSet) {
        match token {
            SERVER => {
                let MyHandler(ref mut server) = *self;
                // Accept and drop the socket immediately, this will close
                // the socket and notify the client of the EOF.
                let _ = server.accept();
            }
            CLIENT => {
                // The server just shuts down the socket, let's just
                // shutdown the event loop
                event_loop.shutdown();
            }
            _ => panic!("unexpected token"),
        }
    }
}

// Start handling events
event_loop.run(&mut MyHandler(server)).unwrap();

Modules

prelude
tcp
udp
unix
util	Utilities for non-blocking IO programs

Structs

EventLoop	Single threaded IO event loop.
EventLoopConfig	Configure EventLoop runtime details
EventSet
Events
Io
IoEvent
Ipv4Addr	An IPv4 address.
Ipv6Addr	An IPv6 address.
Poll
PollOpt
Selector
Sender	Sends messages to the EventLoop from other threads.
Timeout
TimerError
Token

Enums

IpAddr	An IP address, either a IPv4 or IPv6 address.
NotifyError

Traits

Evented	A value that may be registered with an EventLoop
Handler
TryAccept
TryRead
TryWrite

Type Definitions

TimerResult