Trait SyncTimer

source

pub trait SyncTimer: Timer {
    // Required method
    fn init<R, F: Fn(&TimerState) -> R>(&mut self, init: F) -> R;

    // Provided method
    fn tick(&mut self) -> bool { ... }
}

Expand description

Describes timer interface that doesn’t require async event loop.

In most cases these timers are implemented by OS calling back a provided callback.

As notification is not done via event loop, timer has to store callback in its own state.

Whenever async timer relies on async event loop to handle notifications

§Usage

use async_timer::timer::{Timer, SyncTimer, new_sync_timer};

use core::sync::atomic::{AtomicBool, Ordering};
use core::time;

use std::thread;

static EXPIRED: AtomicBool = AtomicBool::new(false);
fn on_expire() {
    EXPIRED.store(true, Ordering::Release);
}

let mut work = new_sync_timer(time::Duration::from_secs(1));
assert!(!work.is_ticking());
assert!(!work.is_expired());

work.init(|state| state.register(on_expire as fn()));
work.tick();

assert!(work.is_ticking());
assert!(!work.is_expired());
thread::sleep(time::Duration::from_millis(1250)); //timer is not necessary expires immediately

assert!(work.is_expired());
assert!(EXPIRED.load(Ordering::Acquire));