timeout.tv_usec = 1000 * 1000;
max = -1;
ret = r->pre_select(&rn, &rfds, &wfds, &timeout);
timeout.tv_usec = 1000 * 1000;
max = -1;
ret = r->pre_select(&rn, &rfds, &wfds, &timeout);
PARA_DEBUG_LOG("timeout: %lums\n", tv2ms(&timeout));
ret = para_select(max + 1, &rfds, &wfds, &timeout);
PARA_DEBUG_LOG("timeout: %lums\n", tv2ms(&timeout));
ret = para_select(max + 1, &rfds, &wfds, &timeout);