Trait Oneshot

Source

pub trait Oneshot:
    Send
    + Sync
    + Unpin
    + Future<Output = ()> {
    // Required methods
    fn new(timeout: Duration) -> Self;
    fn is_ticking(&self) -> bool;
    fn is_expired(&self) -> bool;
    fn cancel(&mut self);
    fn restart(&mut self, timeout: Duration, waker: &Waker);
}

Expand description

One-shot timer that expires once

Trait itself describes Future that resolves after timeout

Most common platforms are supplied via alias Timer

§Common implementations:

Windows uses thread pooled timer
Apple systems uses dispatch source API
Posix compatible timer_create, available on major Posix-compliant systems. Depends on availability of siginfo_t::si_value method.
Wasm uses Web API SetTimeout
Dummy timer is used when no implementation is available. Panics when used.

§Feature `tokio_on`

Linux uses timerfd_create, replaces Posix tiemr when enabled.
Other unix systems uses kqueue, replaces Apple timer when enabled.

 use async_timer::oneshot::{Oneshot, Timer};

 use std::time;

 async fn do_stuff() {
     let work = Timer::new(time::Duration::from_secs(2));

     let before = time::SystemTime::now();
     work.await;
     let after = time::SystemTime::now();
     let diff = after.duration_since(before).unwrap();

     assert_eq!(diff.as_secs(), 2);
 }