This new helper expands to __atomic_test_and_set where available; otherwise it expands to atomic_xchg.
Signed-off-by: Emilio G. Cota <c...@braap.org> --- include/qemu/atomic.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h index 5bc4d6c..6132dad 100644 --- a/include/qemu/atomic.h +++ b/include/qemu/atomic.h @@ -134,6 +134,7 @@ }) /* Provide shorter names for GCC atomic builtins, return old value */ +#define atomic_test_and_set(ptr) __atomic_test_and_set(ptr, __ATOMIC_SEQ_CST) #define atomic_fetch_inc(ptr) __atomic_fetch_add(ptr, 1, __ATOMIC_SEQ_CST) #define atomic_fetch_dec(ptr) __atomic_fetch_sub(ptr, 1, __ATOMIC_SEQ_CST) #define atomic_fetch_add(ptr, n) __atomic_fetch_add(ptr, n, __ATOMIC_SEQ_CST) @@ -328,6 +329,7 @@ #endif /* Provide shorter names for GCC atomic builtins. */ +#define atomic_test_and_set(ptr) atomic_xchg(ptr, true) #define atomic_fetch_inc(ptr) __sync_fetch_and_add(ptr, 1) #define atomic_fetch_dec(ptr) __sync_fetch_and_add(ptr, -1) #define atomic_fetch_add __sync_fetch_and_add -- 2.5.0