atomic_cond_read_acquire
atomic_cond_read_acquire(refs, !VAL);
atomic_cond_read_acquire(&lock->val, ticket == (u16)VAL);
#define atomic_long_cond_read_acquire atomic_cond_read_acquire
atomic_cond_read_acquire(&lock->cnts, !(VAL & _QW_LOCKED));
atomic_cond_read_acquire(&lock->cnts, !(VAL & _QW_LOCKED));
val = atomic_cond_read_acquire(&lock->val, !(VAL & _Q_LOCKED_PENDING_MASK));