diff options
Diffstat (limited to 'rust/kernel/time/hrtimer.rs')
| -rw-r--r-- | rust/kernel/time/hrtimer.rs | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs index bc8f85cededb..e1b29cd40397 100644 --- a/rust/kernel/time/hrtimer.rs +++ b/rust/kernel/time/hrtimer.rs @@ -188,6 +188,37 @@ pub trait HrTimerPointer: Sync + Sized { fn start(self, expires: Ktime) -> Self::TimerHandle; } +/// Unsafe version of [`HrTimerPointer`] for situations where leaking the +/// [`HrTimerHandle`] returned by `start` would be unsound. This is the case for +/// stack allocated timers. +/// +/// Typical implementers are pinned references such as [`Pin<&T>`]. +/// +/// # Safety +/// +/// Implementers of this trait must ensure that instances of types implementing +/// [`UnsafeHrTimerPointer`] outlives any associated [`HrTimerPointer::TimerHandle`] +/// instances. +pub unsafe trait UnsafeHrTimerPointer: Sync + Sized { + /// A handle representing a running timer. + /// + /// # Safety + /// + /// If the timer is running, or if the timer callback is executing when the + /// handle is dropped, the drop method of [`Self::TimerHandle`] must not return + /// until the timer is stopped and the callback has completed. + type TimerHandle: HrTimerHandle; + + /// Start the timer after `expires` time units. If the timer was already + /// running, it is restarted at the new expiry time. + /// + /// # Safety + /// + /// Caller promises keep the timer structure alive until the timer is dead. + /// Caller can ensure this by not leaking the returned [`Self::TimerHandle`]. + unsafe fn start(self, expires: Ktime) -> Self::TimerHandle; +} + /// Implemented by [`HrTimerPointer`] implementers to give the C timer callback a /// function to call. // This is split from `HrTimerPointer` to make it easier to specify trait bounds. |