#linux #pidfd

pidfd

Obtain file descriptors which refer to processes

1 unstable release

✓ Uses Rust 2018 edition

new 0.2.3 Dec 3, 2019
0.2.2 Dec 1, 2019
0.2.1 Nov 28, 2019
0.2.0 Nov 27, 2019
0.1.0 Nov 27, 2019

#112 in Unix APIs

26 downloads per month

MIT/Apache

10KB
148 lines

pidfd

This Rust crate provides Linux (>= 5.3) PID file descriptor support. PID file descriptors are created from PIDs of processes, and are guaranteed to always reference the process from which the PID FD was created.

One of the benefits of using a PID FD is the ability to use poll(), select(), and epoll() to monitor when the process has terminated. This makes it ideal for use in asynchronous programming. This crate implements std::future::Future on the PidFd type so that multiple processes can be awaited concurrently.

Linux 5.4 is required to use the waitid feature, which enables fetching the exit status of a pidfd.

use pidfd::PidFd;
use std::{io, process::Command};

fn main() {
    futures::executor::block_on(async move {
        futures::try_join!(
            spawn_sleeper("1", "5"),
            spawn_sleeper("2", "4"),
            spawn_sleeper("3", "3"),
            spawn_sleeper("4", "2"),
            spawn_sleeper("5", "1"),
        ).unwrap();
    })
}

async fn spawn_sleeper(id: &str, timeout: &str) -> io::Result<()> {
    println!("started job {}", id);
    let child = Command::new("/bin/sleep").arg(timeout).spawn().unwrap();
    PidFd::from(child).await?;
    println!("finished job {}", id);
    Ok(())
}

License

Licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Dependencies

~110KB