[sanitizer] Pair atomic acquire with release in BlockingMutex::Unlock
Summary:
Dmitry, seeking your expertise. I believe, the proper way to implement
Lock/Unlock here would be to use acquire/release semantics. Am I missing
something?
Reviewers: dvyukov
Subscribers: llvm-commits, kubamracek
@@ -549,7 +549,7 @@ void BlockingMutex::Lock() {
void BlockingMutex::Unlock() {
atomic_uint32_t *m = reinterpret_cast<atomic_uint32_t *>(&opaque_storage_);
- u32 v = atomic_exchange(m, MtxUnlocked, memory_order_relaxed);
+ u32 v = atomic_exchange(m, MtxUnlocked, memory_order_release);
CHECK_NE(v, MtxUnlocked);
if (v == MtxSleeping) {
#if SANITIZER_FREEBSD
