On 18/05/2016 16:47, Sergey Fedorov wrote: >>> >> 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. > However, there's also __atomic_compare_exchange_n(). Could it be the choice?
cmpxchg is not TAS. I don't see any reason not to use __sync_test_and_set, the only sensible alternative is to ignore the standard and use __atomic_test_and_set on int. Paolo
