killswitch

A killswitch is a special-purpose channel-like object used to signal to tasks that they should terminate.

lib.rs:

This library provides two separate structures for signalling (and receiveing) termination requests [in async contexts]:

• KillSwitch acts as both a trigger and a receiver.
• pair::KillTrig and pair::KillWait (created using [pair::create()]) act as a kill signal sender and receiver.

KillSwitch

Signal a request for (multiple) async tasks to self-terminate.

use std::error::Error;
use tokio::time::{sleep, Duration};
use killswitch::KillSwitch;

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
  let ks = KillSwitch::new();

  tokio::spawn(killable(String::from("test1"), ks.clone()));
  tokio::spawn(killable(String::from("test2"), ks.clone()));

  sleep(Duration::from_secs(1)).await;

  println!("Triggering kill switch");
  ks.trigger();

  tokio::spawn(killable(String::from("test3"), ks.clone()));
  tokio::spawn(killable(String::from("test4"), ks.clone()));

  // Wait for all waiters to drop
  ks.finalize().await;

  Ok(())
}

async fn killable(s: String, ks: KillSwitch) {
  println!("killable({}) entered", s);
  ks.wait().await;
  println!("killable({}) leaving", s);
}

killswitch was developed to help create abortable async tasks in conjuction with multiple-wait features such as the tokio::select! macro.