Crate killswitch_std

killswitch_std

killswitch_std is a simple crate with no dependencies outside of the standard library for creating a thread-safe kill switch

Example

#[tokio::main]
async fn main() {
    use killswitch_std::KillSwitch;
    use std::time::Duration;

    // Create a kill switch
    let kill = KillSwitch::default();

    println!("Is kill switch set? {}", kill);

    // Now make a couple of clones and check
    let k1 = kill.watcher();
    let t1 = tokio::spawn(async move {
        let duration = Duration::from_secs(2);
        for _ in 0..5 {
            tokio::time::sleep(duration).await;
            println!("Kill switch on thread 1: {}", k1);
        }
        println!("Thread 1 wrapping up");
    });

    // Now make a couple of clones and check
    let k2 = kill.watcher();
    let t2 = tokio::spawn(async move {
        let duration = Duration::from_secs(2);
        for _ in 0..5 {
            tokio::time::sleep(duration).await;
            println!("Kill switch on thread 2: {}", k2);
        }
        println!("Thread 2 wrapping up");
    });

    let duration = Duration::from_secs(7);
    tokio::time::sleep(duration).await;
    println!("Flipping kill switch on main thread");
    let _ = kill.kill();

    let _ = tokio::join!(t1, t2);

    println!("All threads finished");
}

Should produce output of the following form:

Is kill switch set? alive
Kill switch on thread 2: alive
Kill switch on thread 1: alive
Kill switch on thread 2: alive
Kill switch on thread 1: alive
Kill switch on thread 2: alive
Kill switch on thread 1: alive
Flipping kill switch on main thread
Kill switch on thread 2: killed
Kill switch on thread 1: killed
Kill switch on thread 1: killed
Thread 1 wrapping up
Kill switch on thread 2: killed
Thread 2 wrapping up
All threads finished

Structs

KillSwitch

Convenience type which wraps a AtomicBool. Initially, is_alive() will return true. The value can be cloned across threads, and once it has been kill()ed, then all of the clones will return false from is_alive().

KillSwitchWatcher

Derived from a KillSwitch, allows to check if the kill switch is still alive, but cannot activate it. This may be useful in separating out a thread which is only watching the value of the kill switch.

Enums

KillSwitchErr

General error type for a KillSwitch