2 releases

0.2.4 Dec 20, 2019
0.2.3 Dec 3, 2019
0.2.1 Nov 28, 2019
0.1.0 Nov 27, 2019

#874 in Unix APIs

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Used in pidfd_getfd


153 lines


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 {
            spawn_sleeper("1", "5"),
            spawn_sleeper("2", "4"),
            spawn_sleeper("3", "3"),
            spawn_sleeper("4", "2"),
            spawn_sleeper("5", "1"),

async fn spawn_sleeper(id: &str, timeout: &str) -> io::Result<()> {
    println!("started job {}", id);

    let exit_status = Command::new("/bin/sleep")

    println!("finished job {}: {}", id, exit_status);


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