async_timer/oneshot/mod.rs
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//! One-shot Timer
use core::{task, time};
use core::marker::Unpin;
use core::future::Future;
///One-shot timer that expires once
///
///Trait itself describes `Future` that resolves after `timeout`
///
///Most common platforms are supplied via alias [Timer](type.Timer.html)
///
///## 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.
///
///```rust, no_run
/// 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);
/// }
///
///```
pub trait Oneshot: Send + Sync + Unpin + Future<Output=()> {
///Creates new instance without actually starting timer.
///
///Timer should start only on first `Future::poll`
fn new(timeout: time::Duration) -> Self;
///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_ticking(&self) -> bool;
///Returns whether timer has expired.
fn is_expired(&self) -> bool;
///Cancels ongoing timer, if it is not expired yet.
fn cancel(&mut self);
///Restarts timer with new timeout value.
///
///If timer is already running, then over-write old value and replaces waker.
fn restart(&mut self, timeout: time::Duration, waker: &task::Waker);
}
mod state;
#[cfg(target_arch = "wasm32")]
pub mod web;
#[cfg(windows)]
pub mod win;
#[cfg(all(unix, not(any(target_os = "macos", target_os = "ios"))))]
pub mod posix;
#[cfg(any(target_os = "macos", target_os = "ios"))]
pub mod apple;
#[cfg(all(feature = "tokio_on", any(target_os = "linux", target_os = "android")))]
pub mod timer_fd;
#[cfg(all(feature = "tokio_on", any(target_os = "bitrig", target_os = "dragonfly", target_os = "freebsd", target_os = "ios", target_os = "macos", target_os = "netbsd", target_os = "openbsd")))]
pub mod kqueue;
pub mod dummy;
mod extra;
pub use extra::NeverTimer;
#[cfg(all(feature = "tokio_on", any(target_os = "linux", target_os = "android")))]
pub use timer_fd::TimerFd;
#[cfg(target_arch = "wasm32")]
///Alias to Web based Timer.
pub type Timer = web::WebTimer;
#[cfg(windows)]
///Alias to Windows Timer
pub type Timer = win::WinTimer;
#[cfg(all(not(feature = "tokio_on"), not(any(target_os = "macos", target_os = "ios")), unix))]
///Alias to Posix Timer
pub type Timer = posix::PosixTimer;
#[cfg(all(feature = "tokio_on", any(target_os = "linux", target_os = "android")))]
///Alias to Linux `timerfd` Timer
pub type Timer = timer_fd::TimerFd;
#[cfg(all(not(feature = "tokio_on"), any(target_os = "macos", target_os = "ios")))]
///Alias to Apple Timer
pub type Timer = apple::AppleTimer;
#[cfg(all(feature = "tokio_on", any(target_os = "bitrig", target_os = "dragonfly", target_os = "freebsd", target_os = "ios", target_os = "macos", target_os = "netbsd", target_os = "openbsd")))]
///Alias to `kqueue` based Timer
pub type Timer = kqueue::KqueueTimer;
#[cfg(not(any(
windows, target_arch = "wasm32", unix,
all(feature = "tokio_on", any(target_os = "bitrig", target_os = "ios", target_os = "macos"))
)))]
///Dummy Timer
pub type Timer = dummy::DummyTimer;