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#![no_std]
#![doc = include_str!("../README.md")]
#![warn(missing_docs)]
//! ## Implementing a timer queue
//!
//! - Define a struct `MyTimerQueue`
//! - Implement [`TimerQueue`] for it
//! - Register it as the global timer queue with [`timer_queue_impl`](crate::timer_queue_impl).
//!
//! ## Example
//!
//! ```
//! use core::task::Waker;
//!
//! use embassy_time::Instant;
//! use embassy_time::queue::{TimerQueue};
//!
//! struct MyTimerQueue{}; // not public!
//!
//! impl TimerQueue for MyTimerQueue {
//! fn schedule_wake(&'static self, at: u64, waker: &Waker) {
//! todo!()
//! }
//! }
//!
//! embassy_time_queue_driver::timer_queue_impl!(static QUEUE: MyTimerQueue = MyTimerQueue{});
//! ```
use core::task::Waker;
/// Timer queue
pub trait TimerQueue {
/// Schedules a waker in the queue to be awoken at moment `at`.
/// If this moment is in the past, the waker might be awoken immediately.
fn schedule_wake(&'static self, at: u64, waker: &Waker);
}
extern "Rust" {
fn _embassy_time_schedule_wake(at: u64, waker: &Waker);
}
/// Schedule the given waker to be woken at `at`.
pub fn schedule_wake(at: u64, waker: &Waker) {
unsafe { _embassy_time_schedule_wake(at, waker) }
}
/// Set the TimerQueue implementation.
///
/// See the module documentation for an example.
#[macro_export]
macro_rules! timer_queue_impl {
(static $name:ident: $t: ty = $val:expr) => {
static $name: $t = $val;
#[no_mangle]
fn _embassy_time_schedule_wake(at: u64, waker: &core::task::Waker) {
<$t as $crate::TimerQueue>::schedule_wake(&$name, at, waker);
}
};
}