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);
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(())
}