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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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use super::{ HasHrTimer, HrTimer, HrTimerCallback, HrTimerCallbackContext, HrTimerHandle, HrTimerMode, RawHrTimerCallback, UnsafeHrTimerPointer,};use core::{marker::PhantomData, pin::Pin, ptr::NonNull};
/// A handle for a `Pin<&mut HasHrTimer>`. When the handle exists, the timer might/// be running.pub struct PinMutHrTimerHandle<'a, T>where T: HasHrTimer<T>,{ pub(crate) inner: NonNull<T>, _p: PhantomData<&'a mut T>,}
// SAFETY: We cancel the timer when the handle is dropped. The implementation of// the `cancel` method will block if the timer handler is running.unsafe impl<'a, T> HrTimerHandle for PinMutHrTimerHandle<'a, T>where T: HasHrTimer<T>,{ fn cancel(&mut self) -> bool { let self_ptr = self.inner.as_ptr();
// SAFETY: As we got `self_ptr` from a reference above, it must point to // a valid `T`. let timer_ptr = unsafe { <T as HasHrTimer<T>>::raw_get_timer(self_ptr) };
// SAFETY: As `timer_ptr` is derived from a reference, it must point to // a valid and initialized `HrTimer`. unsafe { HrTimer::<T>::raw_cancel(timer_ptr) } }}
impl<'a, T> Drop for PinMutHrTimerHandle<'a, T>where T: HasHrTimer<T>,{ fn drop(&mut self) { self.cancel(); }}
// SAFETY: We capture the lifetime of `Self` when we create a// `PinMutHrTimerHandle`, so `Self` will outlive the handle.unsafe impl<'a, T> UnsafeHrTimerPointer for Pin<&'a mut T>where T: Send + Sync, T: HasHrTimer<T>, T: HrTimerCallback<Pointer<'a> = Self>,{ type TimerMode = <T as HasHrTimer<T>>::TimerMode; type TimerHandle = PinMutHrTimerHandle<'a, T>;
unsafe fn start( mut self, expires: <<T as HasHrTimer<T>>::TimerMode as HrTimerMode>::Expires, ) -> Self::TimerHandle { // SAFETY: // - We promise not to move out of `self`. We only pass `self` // back to the caller as a `Pin<&mut self>`. // - The return value of `get_unchecked_mut` is guaranteed not to be null. let self_ptr = unsafe { NonNull::new_unchecked(self.as_mut().get_unchecked_mut()) };
// SAFETY: // - As we derive `self_ptr` from a reference above, it must point to a // valid `T`. // - We keep `self` alive by wrapping it in a handle below. unsafe { T::start(self_ptr.as_ptr(), expires) };
PinMutHrTimerHandle { inner: self_ptr, _p: PhantomData, } }}
impl<'a, T> RawHrTimerCallback for Pin<&'a mut T>where T: HasHrTimer<T>, T: HrTimerCallback<Pointer<'a> = Self>,{ type CallbackTarget<'b> = Self;
unsafe extern "C" fn run(ptr: *mut bindings::hrtimer) -> bindings::hrtimer_restart { // `HrTimer` is `repr(C)` let timer_ptr = ptr.cast::<HrTimer<T>>();
// SAFETY: By the safety requirement of this function, `timer_ptr` // points to a `HrTimer<T>` contained in an `T`. let receiver_ptr = unsafe { T::timer_container_of(timer_ptr) };
// SAFETY: // - By the safety requirement of this function, `timer_ptr` // points to a `HrTimer<T>` contained in an `T`. // - As per the safety requirements of the trait `HrTimerHandle`, the // `PinMutHrTimerHandle` associated with this timer is guaranteed to // be alive until this method returns. That handle borrows the `T` // behind `receiver_ptr` mutably thus guaranteeing the validity of // the reference created below. let receiver_ref = unsafe { &mut *receiver_ptr };
// SAFETY: `receiver_ref` only exists as pinned, so it is safe to pin it // here. let receiver_pin = unsafe { Pin::new_unchecked(receiver_ref) };
// SAFETY: // - By C API contract `timer_ptr` is the pointer that we passed when queuing the timer, so // it is a valid pointer to a `HrTimer<T>` embedded in a `T`. // - We are within `RawHrTimerCallback::run` let context = unsafe { HrTimerCallbackContext::from_raw(timer_ptr) };
T::run(receiver_pin, context).into_c() }}