[−][src]Trait async_timer::oneshot::Oneshot

pub trait Oneshot: Send + Sync + Unpin + Future<Output = ()> {
    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);
}

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 romio_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 futures::executor::block_on;

 use std::time;

 let work = Timer::new(time::Duration::from_secs(2));

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

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

Required methods

fn new(timeout: Duration) -> Self

Creates new instance without actually starting timer.

Timer should start only on first Future::poll

fn is_ticking(&self) -> bool

Returns whether timer is ongoing.

Note that if it returns false it doesn't mean that is_expired will return true as initially timer is not armed.

fn is_expired(&self) -> bool

Returns whether timer has expired.

fn cancel(&mut self)

Cancels ongoing timer, if it is not expired yet.

fn restart(&mut self, timeout: &Duration, waker: &Waker)

Restarts timer with new timeout value.

If timer is already running, then over-write old value and replaces waker.

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Implementors

impl Oneshot for AppleTimer[src]

impl Oneshot for DummyTimer[src]

impl Oneshot for NeverTimer[src]

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