#elif defined(USE_EPOLL)manager->nevents = ISC_SOCKET_MAXEVENTS;manager->events = isc_mem_get(mctx, sizeof(struct epoll_event) *manager->nevents);if (manager->events == NULL)return (ISC_R_NOMEMORY);manager->epoll_fd = epoll_create(manager->nevents);if (manager->epoll_fd == -1) {result = isc__errno2result(errno);isc__strerror(errno, strbuf, sizeof(strbuf));UNEXPECTED_ERROR(__FILE__, __LINE__,"epoll_create %s: %s",isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,ISC_MSG_FAILED, "failed"),strbuf);isc_mem_put(mctx, manager->events,sizeof(struct epoll_event) * manager->nevents);return (result);}
#ifdef USE_WATCHER_THREADresult = watch_fd(manager, manager->pipe_fds[0], SELECT_POKE_READ);if (result != ISC_R_SUCCESS) {close(manager->epoll_fd);isc_mem_put(mctx, manager->events,sizeof(struct epoll_event) * manager->nevents);return (result);}
#endif    /* USE_WATCHER_THREAD */

#elif defined(USE_EPOLL)struct epoll_event event;if (msg == SELECT_POKE_READ)event.events = EPOLLIN;elseevent.events = EPOLLOUT;memset(&event.data, 0, sizeof(event.data));event.data.fd = fd;if (epoll_ctl(manager->epoll_fd, EPOLL_CTL_ADD, fd, &event) == -1 &&errno != EEXIST) {result = isc__errno2result(errno);}return (result);

static isc_threadresult_t
watcher(void *uap) {isc__socketmgr_t *manager = uap;isc_boolean_t done;int ctlfd;int cc;
#ifdef USE_KQUEUEconst char *fnname = "kevent()";
#elif defined (USE_EPOLL)const char *fnname = "epoll_wait()";
#elif defined(USE_DEVPOLL)const char *fnname = "ioctl(DP_POLL)";struct dvpoll dvp;
#elif defined (USE_SELECT)const char *fnname = "select()";int maxfd;
#endifchar strbuf[ISC_STRERRORSIZE];
#ifdef ISC_SOCKET_USE_POLLWATCHpollstate_t pollstate = poll_idle;
#endif/** Get the control fd here.  This will never change.*/ctlfd = manager->pipe_fds[0];done = ISC_FALSE;while (!done) {do {
#ifdef USE_KQUEUEcc = kevent(manager->kqueue_fd, NULL, 0,manager->events, manager->nevents, NULL);
#elif defined(USE_EPOLL)cc = epoll_wait(manager->epoll_fd, manager->events,manager->nevents, -1);
#elif defined(USE_DEVPOLL)dvp.dp_fds = manager->events;dvp.dp_nfds = manager->nevents;
#ifndef ISC_SOCKET_USE_POLLWATCHdvp.dp_timeout = -1;
#elseif (pollstate == poll_idle)dvp.dp_timeout = -1;elsedvp.dp_timeout = ISC_SOCKET_POLLWATCH_TIMEOUT;
#endif    /* ISC_SOCKET_USE_POLLWATCH */cc = ioctl(manager->devpoll_fd, DP_POLL, &dvp);
#elif defined(USE_SELECT)LOCK(&manager->lock);memcpy(manager->read_fds_copy, manager->read_fds,manager->fd_bufsize);memcpy(manager->write_fds_copy, manager->write_fds,manager->fd_bufsize);maxfd = manager->maxfd + 1;UNLOCK(&manager->lock);cc = select(maxfd, manager->read_fds_copy,manager->write_fds_copy, NULL, NULL);
#endif    /* USE_KQUEUE */if (cc < 0 && !SOFT_ERROR(errno)) {isc__strerror(errno, strbuf, sizeof(strbuf));FATAL_ERROR(__FILE__, __LINE__,"%s %s: %s", fnname,isc_msgcat_get(isc_msgcat,ISC_MSGSET_GENERAL,ISC_MSG_FAILED,"failed"), strbuf);}#if defined(USE_DEVPOLL) && defined(ISC_SOCKET_USE_POLLWATCH)if (cc == 0) {if (pollstate == poll_active)pollstate = poll_checking;else if (pollstate == poll_checking)pollstate = poll_idle;} else if (cc > 0) {if (pollstate == poll_checking) {/** XXX: We'd like to use a more* verbose log level as it's actually an* unexpected event, but the kernel bug* reportedly happens pretty frequently* (and it can also be a false positive)* so it would be just too noisy.*/manager_log(manager,ISC_LOGCATEGORY_GENERAL,ISC_LOGMODULE_SOCKET,ISC_LOG_DEBUG(1),"unexpected POLL timeout");}pollstate = poll_active;}
#endif} while (cc < 0);#if defined(USE_KQUEUE) || defined (USE_EPOLL) || defined (USE_DEVPOLL)done = process_fds(manager, manager->events, cc);
#elif defined(USE_SELECT)process_fds(manager, maxfd, manager->read_fds_copy,manager->write_fds_copy);/** Process reads on internal, control fd.*/if (FD_ISSET(ctlfd, manager->read_fds_copy))done = process_ctlfd(manager);
#endif}manager_log(manager, TRACE, "%s",isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,ISC_MSG_EXITING, "watcher exiting"));return ((isc_threadresult_t)0);
}

static isc_boolean_t
process_fds(isc__socketmgr_t *manager, struct epoll_event *events, int nevents)
{int i;isc_boolean_t done = ISC_FALSE;
#ifdef USE_WATCHER_THREADisc_boolean_t have_ctlevent = ISC_FALSE;
#endifif (nevents == manager->nevents) {manager_log(manager, ISC_LOGCATEGORY_GENERAL,ISC_LOGMODULE_SOCKET, ISC_LOG_INFO,"maximum number of FD events (%d) received",nevents);}for (i = 0; i < nevents; i++) {REQUIRE(events[i].data.fd < (int)manager->maxsocks);
#ifdef USE_WATCHER_THREADif (events[i].data.fd == manager->pipe_fds[0]) {have_ctlevent = ISC_TRUE;continue;}
#endifif ((events[i].events & EPOLLERR) != 0 ||(events[i].events & EPOLLHUP) != 0) {/** epoll does not set IN/OUT bits on an erroneous* condition, so we need to try both anyway.  This is a* bit inefficient, but should be okay for such rare* events.  Note also that the read or write attempt* won't block because we use non-blocking sockets.*/events[i].events |= (EPOLLIN | EPOLLOUT);}process_fd(manager, events[i].data.fd,(events[i].events & EPOLLIN) != 0,(events[i].events & EPOLLOUT) != 0);}#ifdef USE_WATCHER_THREADif (have_ctlevent)done = process_ctlfd(manager);
#endifreturn (done);
}