+
+ memset(&event, 0, sizeof event);
+ event.events = EPOLLIN;
+ event.data.u32 = i;
+ if (epoll_ctl(dpif->epoll_fd, EPOLL_CTL_ADD,
+ nl_sock_fd(dpif->upcall_socks[i]), &event) < 0) {
+ error = errno;
+ destroy_upcall_socks(dpif);
+ return error;
+ }