Crate killswitch

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.

Modules

pair

The paired killswitch is separated into a KillTrig (used to trigger a shutdown notification) and a KillWait (used to wait for the killswitch to be triggered).

Structs

FinalizedFuture

Used to wait for all waiters to deregister.

KillSwitch

The KillSwitch is used both to signal termination and waiting for termination.

WaitFuture

A future used to wait for a KillSwitch to become triggered.