atomic_fetch_add_explicit
*ret = atomic_fetch_add_explicit(&refcnt->val, 1, memory_order_relaxed) + 1;
#define tsan_add(ptr, n) atomic_fetch_add_explicit((ptr), (n), memory_order_relaxed)
atomic_fetch_add_explicit(&ask[i], 1, memory_order_relaxed);
atomic_fetch_add_explicit(&got[i], 1, memory_order_relaxed);
sn->sn_gen = atomic_fetch_add_explicit(&sigev_generation, 1,
atomic_fetch_add_explicit(object, operand, memory_order_seq_cst)
atomic_fetch_add_explicit(&sigs, 1, memory_order_relaxed);