ringbahn is a crate integrating an io-uring reactor into Rust's async/await and futures ecosystem. It provides an interface to perform IO on top of io-uring which is efficient, zero cost, and completely memory safe.
The Berlin Ringbahn is a double-tracked commuter rail line which form complete ring around the center of the city of Berlin. Similarly, io-uring is a new interface for asynchronous IO with the Linux kernel built on top of a double ring buffer data structure.
io-uring is the future of high performance IO on Linux. It is the only realistic way to perform asynchronous file IO on Linux, and benchmarks demonstrate that it is substantially more performant than other interfaces of asynchronous IO of all types. The interface supports all the major forms of IO supported by Linux, and the set of operations it supports continues to grow rapidly.
Rust needs a safe, zero-cost, easy to use interface for io-uring. This can become a major differentiator for Rust as a systems language for high performance network services. Unfortunately io-uring presents some unique challenges when creating a safe and correct interface. This is because unlike epoll, io-uring is a completion based API, not a readiness based API. That presents unique safety challenges when integrating with Rust's async/await ecosystem.
ringbahn demonstrates that it is possible to provide a safe interface for io-uring in Rust. Currently it is a prototype; more complete, advanced, and performant APIs are certainly possible. However, I hope that this library acts as a stepping stone toward a correct interface for io-uring in Rust.
This is currently a very experimental prototype. It contains a lot of unsafe code which has not been sufficiently tested. Please do not use it in production. Tests, bug reports, feedback, and experiments are all very welcome at this stage.
ringbahn is licensed under your choice of MIT or Apache-2.0.