forked from M-Labs/zynq-rs
libcortex_a9/mutex: use AcqRel for CAS operations
This commit is contained in:
parent
bb09d25378
commit
c13ca614ef
@ -3,7 +3,7 @@ use core::sync::atomic::{AtomicU32, Ordering};
|
||||
use core::cell::UnsafeCell;
|
||||
use super::{
|
||||
spin_lock_yield, notify_spin_lock,
|
||||
asm::{dmb, enter_critical, exit_critical}
|
||||
asm::{enter_critical, exit_critical}
|
||||
};
|
||||
|
||||
const LOCKED: u32 = 1;
|
||||
@ -32,30 +32,27 @@ impl<T> Mutex<T> {
|
||||
/// Lock the Mutex, blocks when already locked
|
||||
pub fn lock(&self) -> MutexGuard<T> {
|
||||
let mut irq = unsafe { enter_critical() };
|
||||
while self.locked.compare_and_swap(UNLOCKED, LOCKED, Ordering::Acquire) != UNLOCKED {
|
||||
while self.locked.compare_and_swap(UNLOCKED, LOCKED, Ordering::AcqRel) != UNLOCKED {
|
||||
unsafe {
|
||||
exit_critical(irq);
|
||||
spin_lock_yield();
|
||||
irq = enter_critical();
|
||||
}
|
||||
}
|
||||
dmb();
|
||||
MutexGuard { mutex: self, irq }
|
||||
}
|
||||
|
||||
pub fn try_lock(&self) -> Option<MutexGuard<T>> {
|
||||
let irq = unsafe { enter_critical() };
|
||||
if self.locked.compare_and_swap(UNLOCKED, LOCKED, Ordering::Acquire) != UNLOCKED {
|
||||
if self.locked.compare_and_swap(UNLOCKED, LOCKED, Ordering::AcqRel) != UNLOCKED {
|
||||
unsafe { exit_critical(irq) };
|
||||
None
|
||||
} else {
|
||||
dmb();
|
||||
Some(MutexGuard { mutex: self, irq })
|
||||
}
|
||||
}
|
||||
|
||||
fn unlock(&self) {
|
||||
dmb();
|
||||
self.locked.store(UNLOCKED, Ordering::Release);
|
||||
|
||||
notify_spin_lock();
|
||||
|
Loading…
Reference in New Issue
Block a user