Async file I/O with aio* functions

aio_read.rs

// Async file I/O

use libc::{aio_read, aiocb, aio_error, aio_return};
use std::fs::File;
use std::os::unix::io::AsRawFd;
fn main() {
    let file = File::open("src/main.rs").unwrap();
    let mut buf = [0; 1024];
    let mut cb = aiocb {
        aio_fildes: file.as_raw_fd(),
        aio_buf: buf.as_mut_ptr() as *mut libc::c_void,
        aio_nbytes: buf.len() as libc::size_t,
        aio_offset: 0,
        aio_reqprio: 0,
        aio_lio_opcode: 0,
        aio_sigevent: unsafe{::std::mem::zeroed()},
    };
    unsafe {
        if aio_read(&mut cb) < 0 { panic!("aio_read failed"); }
        while aio_error(&cb) == libc::EINPROGRESS {
            println!("waiting for read to complete");
        }
        let read = aio_return(&mut cb);
        if read < 0 { panic!("aio_return failed"); }
        println!("read {} bytes", read);
    }
    println!("{}", String::from_utf8_lossy(buf.as_ref()));
}