Struct lib_wc::sync::ShutdownListener

pub struct ShutdownListener { /* private fields */ }

Listens for a shutdown signal.

Shutdown is signalled using a broadcast::Receiver. Only a single value is ever sent. Once a value has been sent via the broadcast channel, shutdown should occur.

The ShutdownListener struct listens for the signal and tracks that the signal has been received. Callers may query for whether the shutdown signal has been received or not.

Implementations

impl ShutdownListener

pub fn is_shutdown(&self) -> bool

Returns true if the shutdown signal has been received.

Examples

use lib_wc::sync::ShutdownController;
use tokio::task::spawn;

#[tokio::main]
async fn main() {
  let shutdown = ShutdownController::new();
  let mut shutdown_listener = shutdown.subscribe();
  assert!(!shutdown_listener.is_shutdown());

  // Spawn a task
  let t = spawn({
   async move {
    shutdown_listener.recv().await;
    assert!(shutdown_listener.is_shutdown());
   }
  });

  shutdown.shutdown().await;
}

pub async fn recv(&mut self)

Receive the shutdown notice, waiting if necessary.

Examples

use tokio::select;
use lib_wc::sync::ShutdownListener;
use lib_wc::sync::RateLimiter;

/// A task that continuously does work at a fixed rate, but exits when shutdown is initiated.
async fn long_lived_task(mut shutdown: ShutdownListener, rate_limiter: RateLimiter) {
   while !shutdown.is_shutdown() {
      select! {
        _ = shutdown.recv() => { return; }
        _ = rate_limiter.throttle(|| async { /* do work */ }) => { println!("tick"); }
      }
  }
}

Trait Implementations

impl Debug for ShutdownListener

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.