THR_UMTX_TRYLOCK_PERSIST
ret = THR_UMTX_TRYLOCK_PERSIST(curthread, &(*mutex)->m_lock);
ret = THR_UMTX_TRYLOCK_PERSIST(curthread, &m->m_lock);
ret = THR_UMTX_TRYLOCK_PERSIST(curthread, &m->m_lock);
return (THR_UMTX_TRYLOCK_PERSIST(curthread, &lck->s_lock));
while (THR_UMTX_TRYLOCK_PERSIST(curthread, &lck->s_lock) != 0) {