"This Project has been archived by the owner, who is no longer providing support. The project remains available to authorized users on a "read only" basis."
A runtime for writing reliable, asynchronous, and slim applications with the Rust programming language. It is:
Fast: Tokio's zero-cost abstractions give you bare-metal performance.
Reliable: Tokio leverages Rust's ownership, type system, and concurrency model to reduce bugs and ensure thread safety.
Scalable: Tokio has a minimal footprint, and handles backpressure and cancellation naturally.
Website | Guides | API Docs | Chat
Tokio is an event-driven, non-blocking I/O platform for writing asynchronous applications with the Rust programming language. At a high level, it provides a few major components:
- A multithreaded, work-stealing based task scheduler.
- A reactor backed by the operating system's event queue (epoll, kqueue, IOCP, etc...).
- Asynchronous TCP and UDP sockets.
These components provide the runtime components necessary for building an asynchronous application.
A basic TCP echo server with Tokio.
Make sure you activated the full features of the tokio crate on Cargo.toml:
[dependencies]
tokio = { version = "1.21.2", features = ["full"] }Then, on your main.rs:
use tokio::net::TcpListener;use tokio::io::{AsyncReadExt,AsyncWriteExt};#[tokio::main]asyncfnmain() -> Result<(),Box<dyn std::error::Error>>{let listener = TcpListener::bind("127.0.0.1:8080").await?;loop{let(mut socket, _) = listener.accept().await?;
tokio::spawn(asyncmove{letmut buf = [0;1024];// In a loop, read data from the socket and write the data back.loop{let n = match socket.read(&mut buf).await{// socket closedOk(n)if n == 0 => return,Ok(n) => n,Err(e) => {eprintln!("failed to read from socket; err = {:?}", e);return;}};// Write the data backifletErr(e) = socket.write_all(&buf[0..n]).await{eprintln!("failed to write to socket; err = {:?}", e);return;}}});}}More examples can be found here. For a larger "real world" example, see the mini-redis repository.
To see a list of the available features flags that can be enabled, check our docs.
First, see if the answer to your question can be found in the Guides or the API documentation. If the answer is not there, there is an active community in the Tokio Discord server. We would be happy to try to answer your question. You can also ask your question on the discussions page.
🎈 Thanks for your help improving the project! We are so happy to have you! We have a contributing guide to help you get involved in the Tokio project.
In addition to the crates in this repository, the Tokio project also maintains several other libraries, including:
hyper: A fast and correct HTTP/1.1 and HTTP/2 implementation for Rust.tonic: A gRPC over HTTP/2 implementation focused on high performance, interoperability, and flexibility.warp: A super-easy, composable, web server framework for warp speeds.tower: A library of modular and reusable components for building robust networking clients and servers.tracing(formerlytokio-trace): A framework for application-level tracing and async-aware diagnostics.rdbc: A Rust database connectivity library for MySQL, Postgres and SQLite.mio: A low-level, cross-platform abstraction over OS I/O APIs that powerstokio.bytes: Utilities for working with bytes, including efficient byte buffers.loom: A testing tool for concurrent Rust code
The Tokio repository contains multiple crates. Each crate has its own changelog.
tokio- view changelogtokio-util- view changelogtokio-stream- view changelogtokio-macros- view changelogtokio-test- view changelog
Tokio will keep a rolling MSRV (minimum supported rust version) policy of at least 6 months. When increasing the MSRV, the new Rust version must have been released at least six months ago. The current MSRV is 1.49.0.
Tokio doesn't follow a fixed release schedule, but we typically make one to two new minor releases each month. We make patch releases for bugfixes as necessary.
For the purposes of making patch releases with bugfixes, we have designated certain minor releases as LTS (long term support) releases. Whenever a bug warrants a patch release with a fix for the bug, it will be backported and released as a new patch release for each LTS minor version. Our current LTS releases are:
1.18.x- LTS release until June 20231.20.x- LTS release until September 2023.
Each LTS release will continue to receive backported fixes for at least a year. If you wish to use a fixed minor release in your project, we recommend that you use an LTS release.
To use a fixed minor version, you can specify the version with a tilde. For
example, to specify that you wish to use the newest 1.18.x patch release, you
can use the following dependency specification:
tokio = { version = "~1.18", features = [...] }
This project is licensed under the MIT license.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Tokio by you, shall be licensed as MIT, without any additional terms or conditions.