rename borrow to access

This commit is contained in:
Jorge Aparicio 2017-04-21 21:38:39 -05:00
parent 296c88c49c
commit d0ddc322e3
7 changed files with 83 additions and 82 deletions

View file

@ -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