8 releases

0.2.1 Jun 28, 2022
0.2.0 Apr 10, 2022
0.1.3 Feb 1, 2021
0.1.2-alpha.1 Jul 29, 2020
0.0.0 Jul 5, 2020

#234 in Asynchronous

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Used in 10 crates (3 directly)


3.5K SLoC

Nuclei: Proactive IO & Runtime system

Nuclei is a proactor-based IO system which is runtime agnostic and can work with any runtime. The proactor system's design principles are matching Boost Asio. Nuclei is not using a conventional reactor approach. It is completely asynchronous, and it's wrapping poll based IO in a proactive fashion.

Nuclei uses epoll on Linux as the primary evented IO backend, secondarily (given system support) you can use io_uring. On MacOS, Nuclei is using kqueue. On Windows, the IOCP backend will be used.

The current io_uring implementation needs a modern Linux kernel (5.6+).


  • Async TCP, UDP, Unix domain sockets and files...
  • The proactor system doesn't block
  • Scatter/Gather operations
  • Minimal allocation
  • More expressive than any other runtime
  • Completely asynchronous I/O system with lock free programming


Please head to examples directory to run the examples:

$ cd examples
$ cargo run --example fread-vect


$ cargo test --no-default-features --features=iouring # For iouring
$ cargo test # For others


Evented IO backend

When the iouring feature gate is not enabled, the platforms evented backend is used. For example, on Linux, epoll would be used.


Executor is using async-global-executor. Available features are:

  • async-exec: Uses async-io feature of async-global-executor.
  • tokio
  • tokio02
  • tokio03


Licensed under either of Apache License, Version 2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Gif is from the documentary called "Particle Fever".


~197K SLoC