Trait TimerContext

pub trait TimerContext: InstantContext + TimerBindingsTypes {
    // Required methods
    fn new_timer(&mut self, id: Self::DispatchId) -> Self::Timer;
    fn schedule_timer_instant(
        &mut self,
        time: Self::Instant,
        timer: &mut Self::Timer,
    ) -> Option<Self::Instant>;
    fn cancel_timer(&mut self, timer: &mut Self::Timer) -> Option<Self::Instant>;
    fn scheduled_instant(
        &self,
        timer: &mut Self::Timer,
    ) -> Option<Self::Instant>;
    fn unique_timer_id(&self, timer: &Self::Timer) -> Self::UniqueTimerId;

    // Provided method
    fn schedule_timer(
        &mut self,
        duration: Duration,
        timer: &mut Self::Timer,
    ) -> Option<Self::Instant> { ... }
}

A context providing time scheduling to core.

Required Methods

fn new_timer(&mut self, id: Self::DispatchId) -> Self::Timer

Creates a new timer that dispatches id back to core when fired.

Creating a new timer is an expensive operation and should be used sparingly. Modules should prefer to create a timer on creation and then schedule/reschedule it as needed. For modules with very dynamic timers, a [LocalTimerHeap] tied to a larger Timer might be a better alternative than creating many timers.

fn schedule_timer_instant( &mut self, time: Self::Instant, timer: &mut Self::Timer, ) -> Option<Self::Instant>

Schedule a timer to fire at some point in the future. Returns the previously scheduled instant, if this timer was scheduled.

fn cancel_timer(&mut self, timer: &mut Self::Timer) -> Option<Self::Instant>

Cancel a timer.

Cancels timer, returning the instant it was scheduled for if it was scheduled.

Note that there’s no guarantee that observing None means that the dispatch procedure for a previously fired timer has already concluded. It is possible to observe None here while the DispatchId timer was created with is still making its way to the module that originally scheduled this timer. If Some is observed, however, then the TimerContext guarantees this timer will not fire until [schedule_timer_instant] is called to reschedule it.

fn scheduled_instant(&self, timer: &mut Self::Timer) -> Option<Self::Instant>

Get the instant a timer will fire, if one is scheduled.

fn unique_timer_id(&self, timer: &Self::Timer) -> Self::UniqueTimerId

Retrieves the timer id for timer.

This can be used with TimerHandler::handle_timer to match a [Self::Timer] instance with a firing event.

Provided Methods

fn schedule_timer( &mut self, duration: Duration, timer: &mut Self::Timer, ) -> Option<Self::Instant>

Like [schedule_timer_instant] but schedules a time for duration in the future.

Implementors