+ ret = readv_nonblock(rn->fd, iov, iovcnt, &s->rfds, &num_bytes);
+ if (num_bytes == 0)
+ goto out;
+ if (num_bytes <= iov[0].iov_len) /* only the first buffer was filled */
+ btr_add_output_pool(rn->btrp, num_bytes, btrn);
+ else { /* both buffers contain data */
+ btr_add_output_pool(rn->btrp, iov[0].iov_len, btrn);
+ btr_add_output_pool(rn->btrp, num_bytes - iov[0].iov_len, btrn);