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-rw-r--r--src/lib.rs73
1 files changed, 37 insertions, 36 deletions
diff --git a/src/lib.rs b/src/lib.rs
index a0c8a3b..74fcebe 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -420,20 +420,17 @@ impl<T, TASK> Local<T, TASK> {
unsafe impl<T, TASK> Sync for Local<T, TASK> {}
/// A resource with ceiling `C`
-///
-/// Only tasks with priority equal to or smaller than `C` can access this
-/// resource
pub struct Resource<T, C> {
_ceiling: PhantomData<C>,
data: UnsafeCell<T>,
}
-impl<T, CEILING> Resource<T, C<CEILING>>
+impl<T, RC> Resource<T, C<RC>>
where
- CEILING: GreaterThanOrEqual<U0>,
- CEILING: LessThanOrEqual<UMAX>,
+ RC: GreaterThanOrEqual<U0>,
+ RC: LessThanOrEqual<UMAX>,
{
- /// Creates a new resource with the specified `CEILING`
+ /// Creates a new resource
pub const fn new(data: T) -> Self {
Resource {
_ceiling: PhantomData,
@@ -442,21 +439,27 @@ where
}
}
-impl<T, CEILING> Resource<T, C<CEILING>> {
- /// Borrows the resource for the duration of a critical section
+impl<T, RC> Resource<T, C<RC>> {
+ /// Grants data race free and deadlock free access to the resource data
///
/// This operation is zero cost and doesn't impose any additional blocking.
///
- /// **NOTE** Only tasks with a priority equal to or smaller than the
- /// resource ceiling can access the resource.
- pub fn borrow<'cs, PRIORITY, CCEILING>(
+ /// # Requirements
+ ///
+ /// To access the resource data these conditions must be met:
+ ///
+ /// - The resource ceiling must be greater than or equal to the task
+ /// priority
+ /// - The system ceiling must be greater than or equal to the resource
+ /// ceiling
+ pub fn access<'cs, TP, SC>(
&'static self,
- _priority: &P<PRIORITY>,
- _current_ceiling: &'cs C<CCEILING>,
+ _priority: &P<TP>,
+ _current_ceiling: &'cs C<SC>,
) -> Ref<'cs, T>
where
- CCEILING: GreaterThanOrEqual<CEILING>,
- CEILING: GreaterThanOrEqual<PRIORITY>,
+ RC: GreaterThanOrEqual<TP>,
+ SC: GreaterThanOrEqual<RC>,
{
unsafe { Ref::new(&*self.data.get()) }
}
@@ -492,16 +495,16 @@ where
}
}
-impl<Periph, CEILING> Peripheral<Periph, C<CEILING>> {
- /// See [Resource.borrow](./struct.Resource.html#method.borrow)
- pub fn borrow<'cs, PRIORITY, CCEILING>(
+impl<Periph, RC> Peripheral<Periph, C<RC>> {
+ /// See [Resource.access](./struct.Resource.html#method.access)
+ pub fn access<'cs, TP, SC>(
&'static self,
- _priority: &P<PRIORITY>,
- _current_ceiling: &'cs C<CCEILING>,
+ _priority: &P<TP>,
+ _system_ceiling: &'cs C<SC>,
) -> Ref<'cs, Periph>
where
- CCEILING: GreaterThanOrEqual<CEILING>,
- CEILING: GreaterThanOrEqual<PRIORITY>,
+ RC: GreaterThanOrEqual<TP>,
+ SC: GreaterThanOrEqual<RC>,
{
unsafe { Ref::new(&*self.peripheral.get()) }
}
@@ -569,19 +572,17 @@ pub struct C<T> {
_marker: PhantomData<T>,
}
-impl<CURRENT> C<CURRENT> {
- /// Raises the ceiling to match `resource`'s ceiling
- pub fn raise<HIGHER, RES, R, F>(&self, _resource: &'static RES, f: F) -> R
+impl<SC> C<SC> {
+ /// Raises the system ceiling to match the `resource` ceiling
+ pub fn raise<RC, RES, R, F>(&self, _resource: &'static RES, f: F) -> R
where
- RES: ResourceLike<Ceiling = HIGHER>,
- HIGHER: Cmp<CURRENT, Output = Greater>,
- HIGHER: Cmp<UMAX, Output = Less>,
- HIGHER: Unsigned,
- F: FnOnce(&C<HIGHER>) -> R,
+ RES: ResourceLike<Ceiling = RC>,
+ RC: Cmp<SC, Output = Greater> + Cmp<UMAX, Output = Less> + Unsigned,
+ F: FnOnce(&C<RC>) -> R,
{
unsafe {
let old_basepri = basepri::read();
- basepri_max::write(logical2hw(HIGHER::to_u8()));
+ basepri_max::write(logical2hw(RC::to_u8()));
barrier!();
let ret = f(&C { _marker: PhantomData });
barrier!();
@@ -614,12 +615,12 @@ pub unsafe trait ResourceLike {
type Ceiling;
}
-unsafe impl<P, CEILING> ResourceLike for Peripheral<P, C<CEILING>> {
- type Ceiling = CEILING;
+unsafe impl<P, RC> ResourceLike for Peripheral<P, C<RC>> {
+ type Ceiling = RC;
}
-unsafe impl<T, CEILING> ResourceLike for Resource<T, C<CEILING>> {
- type Ceiling = CEILING;
+unsafe impl<T, RC> ResourceLike for Resource<T, C<RC>> {
+ type Ceiling = RC;
}
/// Type-level `>=` operator