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https://github.com/rtic-rs/rtic.git
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failed attempt at new claim
This commit is contained in:
pln
parent
8e0569c396
commit
9ede9215c2
1 changed files with 265 additions and 171 deletions
422
src/lib.rs
422
src/lib.rs
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@ -423,71 +423,6 @@ impl<T, CEILING> Res<T, C<CEILING>> {
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ret
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}
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}
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// / Locks the resource for the duration of the critical section `f`
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// /
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// / For the duration of the critical section, tasks whose priority level is
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// / smaller than or equal to the resource `CEILING` will be prevented from
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// / preempting the current task.
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// /
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// / Within this critical section, resources with ceiling equal to or smaller
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// / than `CEILING` can be borrowed at zero cost. See
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// / [Resource.borrow](struct.Resource.html#method.borrow).
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// #[cfg(not(thumbv6m))]
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// pub fn claim_mut<R, PRIOTASK, CURRCEIL, F>(
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// &'static self,
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// _prio: &P<PRIOTASK>,
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// _curr_ceil: &C<CURRCEIL>,
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// f: F,
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// ) -> R
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// where
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// F: FnOnce(&mut T, &C<<CEILING as Max<CURRCEIL>>::Output>) -> R,
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// PRIOTASK: Unsigned,
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// CURRCEIL: Unsigned,
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// CEILING: GreaterThanOrEqual<PRIOTASK> + Max<CURRCEIL> + Level + Unsigned,
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// {
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// unsafe {
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// match self._state.get() {
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// State::Free => {
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// let c1 = <CURRCEIL>::to_u8();
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// let c2 = <CEILING>::to_u8();
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// if c2 > c1 {
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// let old_basepri = basepri::read();
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// basepri_max::write(<CEILING>::hw());
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// barrier!();
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// self._state.set(State::LockedMut);
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// barrier!();
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//
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// let ret = f(
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// &mut *self.data.get(),
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// &C { _marker: PhantomData },
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// );
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//
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// barrier!();
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// self._state.set(State::Free);
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// barrier!();
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// basepri::write(old_basepri);
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// ret
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// } else {
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// self._state.set(State::LockedMut);
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// barrier!();
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//
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// let ret = f(
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// &mut *self.data.get(),
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// &C { _marker: PhantomData },
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// );
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//
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// barrier!();
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// self._state.set(State::Free);
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// ret
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//
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// }
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// }
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// _ => panic!("Resource already locked)"),
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// }
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// }
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// }
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}
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unsafe impl<T, C> Sync for Res<T, C>
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@ -496,145 +431,304 @@ where
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{
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}
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/*
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// re-implementation of the original claim API
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impl<T, CEILING> Res<T, C<CEILING>> {
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/// Locks the resource for the duration of the critical section `f`
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///
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/// For the duration of the critical section, tasks whose priority level is
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/// smaller than or equal to the resource `CEILING` will be prevented from
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/// preempting the current task.
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///
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/// Within this critical section, resources with ceiling equal to or smaller
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/// than `CEILING` can be borrowed at zero cost. See
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/// [Resource.borrow](struct.Resource.html#method.borrow).
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#[cfg(not(thumbv6m))]
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pub fn claim<R, PRIOTASK, CURRCEIL, F>(
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&'static self,
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_prio: &P<PRIOTASK>,
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_curr_ceil: &C<CURRCEIL>,
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f: F,
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) -> R
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/// Nem attempt
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use core::cell::RefCell;
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use core::cell::RefMut;
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//use core::borrow::BorrowMut;
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/// A resource
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pub struct ResRef<T, CEILING> {
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_ceiling: PhantomData<CEILING>,
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data: UnsafeCell<RefCell<T>>,
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}
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impl<T, C> ResRef<T, C> {
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/// Creates a new resource with ceiling `C`
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pub const fn new(data: T) -> Self
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where
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F: FnOnce(Ref<T>, &C<<CEILING as Max<CURRCEIL>>::Output>) -> R,
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PRIOTASK: Unsigned,
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CURRCEIL: Unsigned,
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CEILING: GreaterThanOrEqual<PRIOTASK> + Max<CURRCEIL> + Level + Unsigned,
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C: Ceiling,
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{
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match self._state.get() {
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State::LockedMut => panic!("Resource already locked)"),
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_ => unsafe {
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let c1 = <CURRCEIL>::to_u8();
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let c2 = <CEILING>::to_u8();
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if c2 > c1 {
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let old_basepri = basepri::read();
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basepri_max::write(<CEILING>::hw());
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barrier!();
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let s = self._state.get();
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self._state.set(State::LockedMut);
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barrier!();
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let ret = f(
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Ref::new(&*self.data.get()),
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&C { _marker: PhantomData },
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);
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barrier!();
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self._state.set(s);
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barrier!();
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basepri::write(old_basepri);
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ret
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} else {
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let s = self._state.get();
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self._state.set(State::LockedMut);
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barrier!();
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let ret = f(
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Ref::new(&*self.data.get()),
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&C { _marker: PhantomData },
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);
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barrier!();
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self._state.set(s);
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ret
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}
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},
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ResRef {
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_ceiling: PhantomData,
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data: UnsafeCell::new(RefCell::new(data)),
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}
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}
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}
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impl<T, CEILING> ResRef<T, C<CEILING>> {
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/// Locks the resource for the duration of the critical section `f`
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///
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/// For the duration of the critical section, tasks whose priority level is
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/// smaller than or equal to the resource `CEILING` will be prevented from
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/// preempting the current task.
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///
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/// Within this critical section, resources with ceiling equal to or smaller
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/// than `CEILING` can be borrowed at zero cost. See
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/// [Resource.borrow](struct.Resource.html#method.borrow).
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/// claim takes three args of type R, PRIOTASK, CURRCEIL, F
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/// R is the Resource to lock (self)
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/// PRIOTASK is the priority of the task (context) calling claim
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/// CURRCEIL is the current system ceiling
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///
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/// F is the type of the closure, hande &T and &C
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/// &T is a read only reference to the data
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/// &C is the new system ceiling
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///
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/// Usage example: a task at prio P1, claiming R1 and R2.
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/// fn j(_task: Exti0, p: P1) {
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/// R1.claim_mut(
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/// &p, &p.as_ceiling(), |a, c| {
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/// R2.claim_mut(
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/// &p, &c, |b, _| {
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/// b.y = a[0]; // b is mutable
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/// a[1] = b.y; // a is mutable
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/// }
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/// );
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/// a[2] = 0; // a is mutable
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/// }
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/// );
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/// }
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/// The implementation satisfies the following
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/// 1. Race free access to the resources under the Stack Resource Policy (SRP)
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/// System ceiling SC, is implemented by the NVIC as MAX(TASKPRI, BASEPRPI)
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/// Hence in case TASKPRI = SC, the BASEPRI register does not need to be updated
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/// as checked by c2 > c1 (this an optimization)
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///
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/// 2. Static (compile time verification) that SC >= TASKPRI
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/// This is achieved by the type bound CEILING: GreaterThanOrEqual<TASKPRI>
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/// This gives ensurence that no task access a resoure with lower ceiling value than the task
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/// and hence satisfies the soundness rule of SRP
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///
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/// 3. The system ceileng for the closure CS = MAX(CURRCEIL, R)
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/// This is achieved by &C<<CEILING as Max<CURRCEIL>>::Output>
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/// where Max operates on R and CEILING
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///
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/// 4. Rust aliasing rules are ensured as run-time check raises a panic if resourse state is locked
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/// This resembles the RefCell implementation, but the implementation is more strict as multiple
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/// readers are disallowed. Essentially this forbids re-locking
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///
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/// Usage example failing: a task at prio P1, claiming R1 and R1.
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/// fn j(_task: Exti0, p: P1) {
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/// R1.claim_mut(
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/// &p, &p.as_ceiling(), |a1, c| {
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/// R1.claim_mut( <-- at this point a panic will occur
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/// &p, &c, |a2, _| {
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/// }
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/// );
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/// a1[2] = 0; // a is mutable
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/// }
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/// );
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/// }
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///
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/// 5. The ceiling of the closure cannot be leaked
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///
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/// fn jres_opt_leak(_task: Exti0, p: P1) {
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/// R1.claim_mut(
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/// &p, &p.as_ceiling(), |a, c| {
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/// let leak_c = R2.claim_mut(&p, &c, |b, c| c); <-- trying to leak c as a return value
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///
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/// R5.claim_mut(&p, leak_c, |b, c| {}); <-- trying to use a leaked system ceilng
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///
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/// a[2] = 0;
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/// }
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/// );
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/// }
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///
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/// The compiler will reject leakage due to the lifetime, (c in a closure is a &C, so it cannot be returned)
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/// A leakage would indeed be fatal as claim would hand out an unprotected R
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#[cfg(not(thumbv6m))]
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pub fn claim_mut<R, PRIOTASK, CURRCEIL, F>(
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pub fn claim_mut<R, TASKPRI, CURRCEIL, F>(
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&'static self,
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_prio: &P<PRIOTASK>,
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_prio: &P<TASKPRI>,
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_curr_ceil: &C<CURRCEIL>,
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f: F,
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) -> R
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where
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F: FnOnce(&mut T, &C<<CEILING as Max<CURRCEIL>>::Output>) -> R,
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PRIOTASK: Unsigned,
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TASKPRI: Unsigned,
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CURRCEIL: Unsigned,
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CEILING: GreaterThanOrEqual<PRIOTASK> + Max<CURRCEIL> + Level + Unsigned,
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CEILING: GreaterThanOrEqual<TASKPRI> + Max<CURRCEIL> + Level + Unsigned,
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{
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unsafe {
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match self._state.get() {
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State::Free => {
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let c1 = <CURRCEIL>::to_u8();
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let c2 = <CEILING>::to_u8();
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if c2 > c1 {
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let curr_ceil = <CURRCEIL>::to_u8();
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let new_ceil = <CEILING>::to_u8();
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if new_ceil > curr_ceil {
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let old_basepri = basepri::read();
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basepri_max::write(<CEILING>::hw());
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barrier!();
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self._state.set(State::LockedMut);
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barrier!();
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let ret = f(
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&mut *self.data.get(),
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&C { _marker: PhantomData },
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);
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let r: &RefCell<T> = &*self.data.get();
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let rr: RefCell<T> = *r;
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let mut rm: RefMut<T> = rr.borrow_mut();
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let mut t: T = *rm;
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let ret = f(&mut t, &C { _marker: PhantomData });
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barrier!();
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self._state.set(State::Free);
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barrier!();
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basepri::write(old_basepri);
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ret
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} else {
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self._state.set(State::LockedMut);
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barrier!();
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let ret = f(
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&mut *self.data.get(),
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&C { _marker: PhantomData },
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);
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barrier!();
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self._state.set(State::Free);
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ret
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}
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}
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_ => panic!("Resource already locked)"),
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panic!("");
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}
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}
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}
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}
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unsafe impl<T, C> Sync for Res<T, C>
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//
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// /// Read only claim, see claim_mut above
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// #[cfg(not(thumbv6m))]
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// pub fn claim<R, TASKPRI, CURRCEIL, F>(
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// &'static self,
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// _prio: &P<TASKPRI>,
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// _curr_ceil: &C<CURRCEIL>,
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// f: F,
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// ) -> R
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// where
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// F: FnOnce(&T, &C<<CEILING as Max<CURRCEIL>>::Output>) -> R,
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// TASKPRI: Unsigned,
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// CURRCEIL: Unsigned,
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// CEILING: GreaterThanOrEqual<TASKPRI> + Max<CURRCEIL> + Level + Unsigned,
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// {
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// if self._state.get() {
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// unsafe {
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// let curr_ceil = <CURRCEIL>::to_u8();
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// let new_ceil = <CEILING>::to_u8();
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// if new_ceil > curr_ceil {
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// let old_basepri = basepri::read();
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// basepri_max::write(<CEILING>::hw());
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// barrier!();
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// self._state.set(false);
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// barrier!();
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//
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// let ret = f(&*self.data.get(), &C { _marker: PhantomData });
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//
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// barrier!();
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// self._state.set(true);
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// barrier!();
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// basepri::write(old_basepri);
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// ret
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// } else {
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// self._state.set(false);
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// barrier!();
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//
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// let ret = f(&*self.data.get(), &C { _marker: PhantomData });
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//
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// barrier!();
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// self._state.set(true);
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// ret
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// }
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// }
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// } else {
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// panic!("Resource already locked)")
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// }
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// }
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//
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// /// Unsafe version of claim_mut
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// #[cfg(not(thumbv6m))]
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// pub unsafe fn claim_mut_unsafe<R, TASKPRI, CURRCEIL, F>(
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// &'static self,
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// _prio: &P<TASKPRI>,
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// _curr_ceil: &C<CURRCEIL>,
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// f: F,
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// ) -> R
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// where
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// F: FnOnce(&mut T, &C<<CEILING as Max<CURRCEIL>>::Output>) -> R,
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// TASKPRI: Unsigned,
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// CURRCEIL: Unsigned,
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// CEILING: GreaterThanOrEqual<TASKPRI> + Max<CURRCEIL> + Level + Unsigned,
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// {
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//
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// let curr_ceil = <CURRCEIL>::to_u8();
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// let new_ceil = <CEILING>::to_u8();
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// if new_ceil > curr_ceil {
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// let old_basepri = basepri::read();
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// basepri_max::write(<CEILING>::hw());
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// barrier!();
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//
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// let ret = f(&mut *self.data.get(), &C { _marker: PhantomData });
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//
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// barrier!();
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// basepri::write(old_basepri);
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// ret
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// } else {
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//
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// let ret = f(&mut *self.data.get(), &C { _marker: PhantomData });
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//
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// ret
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// }
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// }
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//
|
||||
//
|
||||
// // / Locks the resource for the duration of the critical section `f`
|
||||
// // /
|
||||
// // / For the duration of the critical section, tasks whose priority level is
|
||||
// // / smaller than or equal to the resource `CEILING` will be prevented from
|
||||
// // / preempting the current task.
|
||||
// // /
|
||||
// // / Within this critical section, resources with ceiling equal to or smaller
|
||||
// // / than `CEILING` can be borrowed at zero cost. See
|
||||
// // / [Resource.borrow](struct.Resource.html#method.borrow).
|
||||
// // #[cfg(not(thumbv6m))]
|
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// // pub fn claim_mut<R, PRIOTASK, CURRCEIL, F>(
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// // &'static self,
|
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// // _prio: &P<PRIOTASK>,
|
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// // _curr_ceil: &C<CURRCEIL>,
|
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// // f: F,
|
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// // ) -> R
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// // where
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// // F: FnOnce(&mut T, &C<<CEILING as Max<CURRCEIL>>::Output>) -> R,
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// // PRIOTASK: Unsigned,
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// // CURRCEIL: Unsigned,
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// // CEILING: GreaterThanOrEqual<PRIOTASK> + Max<CURRCEIL> + Level + Unsigned,
|
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// // {
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// // unsafe {
|
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// // match self._state.get() {
|
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// // State::Free => {
|
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// // let c1 = <CURRCEIL>::to_u8();
|
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// // let c2 = <CEILING>::to_u8();
|
||||
// // if c2 > c1 {
|
||||
// // let old_basepri = basepri::read();
|
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// // basepri_max::write(<CEILING>::hw());
|
||||
// // barrier!();
|
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// // self._state.set(State::LockedMut);
|
||||
// // barrier!();
|
||||
// //
|
||||
// // let ret = f(
|
||||
// // &mut *self.data.get(),
|
||||
// // &C { _marker: PhantomData },
|
||||
// // );
|
||||
// //
|
||||
// // barrier!();
|
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// // self._state.set(State::Free);
|
||||
// // barrier!();
|
||||
// // basepri::write(old_basepri);
|
||||
// // ret
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||||
// // } else {
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// // self._state.set(State::LockedMut);
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||||
// // barrier!();
|
||||
// //
|
||||
// // let ret = f(
|
||||
// // &mut *self.data.get(),
|
||||
// // &C { _marker: PhantomData },
|
||||
// // );
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// //
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||||
// // barrier!();
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||||
// // self._state.set(State::Free);
|
||||
// // ret
|
||||
// //
|
||||
// // }
|
||||
// // }
|
||||
// // _ => panic!("Resource already locked)"),
|
||||
// // }
|
||||
// // }
|
||||
// // }
|
||||
//}
|
||||
//
|
||||
unsafe impl<T, C> Sync for ResRef<T, C>
|
||||
where
|
||||
C: Ceiling,
|
||||
{
|
||||
}
|
||||
|
||||
*/
|
||||
|
||||
/// A hardware peripheral as a resource
|
||||
pub struct Peripheral<P, CEILING>
|
||||
where
|
||||
|
|
|
|||
Loading…
Reference in a new issue