On 18/05/16 03:28, Emilio G. Cota wrote: > On Tue, May 17, 2016 at 23:20:11 +0300, Sergey Fedorov wrote: >> On 17/05/16 23:04, Emilio G. Cota wrote: > (snip) >>> +/* >>> + * We might we tempted to use __atomic_test_and_set with __ATOMIC_ACQUIRE; >>> + * however, the documentation explicitly says that we should only pass >>> + * a boolean to it, so we use __sync_lock_test_and_set, which doesn't >>> + * have this limitation, and is documented to have acquire semantics. >>> + */ >>> +#define atomic_test_and_set_acquire(ptr) __sync_lock_test_and_set(ptr, >>> true) >> So you are going to stick to *legacy* built-ins? > Why not? AFAIK the reason to avoid __sync primitives is that in most cases > they include barriers that callers might not necessarily need; __atomic's > allow for finer tuning, which is in general a good thing. However, > __sync_test_and_set has the exact semantics we need, without the limitations > documented for __atomic_test_and_set; so why not use it?
So it should be okay as long as the legacy build-ins are supported. Kind regards, Sergey
