mio 0.4.4

Lightweight non-blocking IO

MIO - Metal IO

MIO is a lightweight IO library for Rust with a focus on adding as little overhead as possible over the OS abstractions.

Build Status crates.io

API documentation


To use mio, first add this to your Cargo.toml:

mio = "0.3.0"

Then, add this to your crate root:

extern crate mio;


  • Event loop backed by epoll, kqueue.
  • Zero allocations at runtime
  • Non-blocking TCP, UDP and Unix domain sockets
  • High performance timer system
  • Thread safe message channel for cross thread communication


  • Signal handling
  • Windows support

Non goals

The following are specifically omitted from MIO and are left to the user or higher level libraries.

  • File operations
  • Thread pools / multi-threaded event loop


Currently, MIO only supports Linux and Darwin. The goal is to support all platforms that support Rust and the readiness IO model.


Please submit PRs containing links to MIO resources.


A group of mio users hang out in the #mio channel on the Mozilla IRC server (irc.mozilla.org). This can be a good place to go for questions.