On 17/05/2016 18:15, Sergey Fedorov wrote: > On 14/05/16 06:34, Emilio G. Cota wrote: >> This new helper expands to __atomic_test_and_set with acquire semantics >> where available; otherwise it expands to __sync_test_and_set, which >> has acquire semantics. > > Why don't also add atomic_clear_release() for completeness?
The previous patch adds atomic_set_release. Paolo > Kind regards, > Sergey > >> >> Signed-off-by: Emilio G. Cota <c...@braap.org> >> --- >> include/qemu/atomic.h | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h >> index 5bc4d6c..6061a46 100644 >> --- a/include/qemu/atomic.h >> +++ b/include/qemu/atomic.h >> @@ -113,6 +113,7 @@ >> } while(0) >> #endif >> >> +#define atomic_test_and_set_acquire(ptr) __atomic_test_and_set(ptr, >> __ATOMIC_ACQUIRE) >> >> /* All the remaining operations are fully sequentially consistent */ >> >> @@ -327,6 +328,8 @@ >> #endif >> #endif >> >> +#define atomic_test_and_set_acquire(ptr) __sync_lock_test_and_set(ptr, true) >> + >> /* Provide shorter names for GCC atomic builtins. */ >> #define atomic_fetch_inc(ptr) __sync_fetch_and_add(ptr, 1) >> #define atomic_fetch_dec(ptr) __sync_fetch_and_add(ptr, -1) >
