The low-level io_uring userspace interface for Rust.
To use io-uring crate, first add this to your Cargo.toml:
[dependencies]
io-uring = "0.6"Next we can start using io-uring crate.
The following is quick introduction using Read for file.
use io_uring::{opcode, types, IoUring};
use std::os::unix::io::AsRawFd;
use std::{fs, io};
fn main() -> io::Result<()> {
let mut ring = IoUring::new(8)?;
let fd = fs::File::open("README.md")?;
let mut buf = vec![0; 1024];
let read_e = opcode::Read::new(types::Fd(fd.as_raw_fd()), buf.as_mut_ptr(), buf.len() as _)
.build()
.user_data(0x42);
// Note that the developer needs to ensure
// that the entry pushed into submission queue is valid (e.g. fd, buffer).
unsafe {
ring.submission()
.push(&read_e)
.expect("submission queue is full");
}
ring.submit_and_wait(1)?;
let cqe = ring.completion().next().expect("completion queue is empty");
assert_eq!(cqe.user_data(), 0x42);
assert!(cqe.result() >= 0, "read error: {}", cqe.result());
Ok(())
}Note that opcode Read is only available after kernel 5.6.
If you use a kernel lower than 5.6, this example will fail.
You can run the test and benchmark of the library with the following commands.
$ cargo run --package io-uring-test
$ cargo bench --package io-uring-bench
This project is licensed under either of
- Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in io-uring by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.