async-signal-with-info 0.0.1

Async signal handling
Documentation

async-signal-with-info

Build License Cargo Documentation

Asynchronous signal handling.

This crate provides the Signals type, which can be used to listen for POSIX signals asynchronously. It can be seen as an asynchronous version of signal_hook::iterator::Signals.

This is a fork of async-signal to also provide siginfo_t via the async stream. As siginfo_t is a Unix specific feature, support for Windows is also removed from the crate.

Implementation

This crate uses the signal_hook_registry crate to register a listener for each signal. That listener will then send a message through a Unix socket to the Signals type, which will receive it and notify the user. Asynchronous notification is done through the futures-channel crate.

A background thread is used for reading signal messages to avoid signal losses caused by buffer overruns, which is a problem for the original crate.

Examples

use async_signal::{Signal, Signals};
use futures_lite::prelude::*;
use signal_hook::low_level;

// Register the signals we want to receive.
let mut signals = Signals::new([
    Signal::Term,
    Signal::Quit,
    Signal::Int,
])?;

// Wait for a signal to be received.
while let Some((signal, siginfo)) = signals.next().await {
    // Print the signal.
    eprintln!("Received signal {:?} {:p}", signal, unsafe { siginfo.si_value().sigval_ptr });

    // After printing it, do whatever the signal was supposed to do in the first place.
    low_level::emulate_default_handler(signal.unwrap() as i32).unwrap();
}

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.