research st, remove all events except epoll.

@@ -55,21 +55,6 @@ DEFINES     = -D$(OS) -DDEBUG -DMD_HAVE_EPOLL -DMALLOC_STACK
 
 
 ##########################
 ##########################
 # Other possible defines:
 # Other possible defines:
-# To use poll(2) instead of select(2) for events checking:
-# DEFINES += -DUSE_POLL
-# You may prefer to use select for applications that have many threads
-# using one file descriptor, and poll for applications that have many
-# different file descriptors.  With USE_POLL poll() is called with at
-# least one pollfd per I/O-blocked thread, so 1000 threads sharing one
-# descriptor will poll 1000 identical pollfds and select would be more
-# efficient.  But if the threads all use different descriptors poll()
-# may be better depending on your operating system's implementation of
-# poll and select.  Really, it's up to you.  Oh, and on some platforms
-# poll() fails with more than a few dozen descriptors.
-#
-# Some platforms allow to define FD_SETSIZE (if select() is used), e.g.:
-# DEFINES += -DFD_SETSIZE=4096
-#
 # To use malloc(3) instead of mmap(2) for stack allocation:
 # To use malloc(3) instead of mmap(2) for stack allocation:
 # DEFINES += -DMALLOC_STACK
 # DEFINES += -DMALLOC_STACK
 #
 #
@@ -77,25 +62,9 @@ DEFINES     = -D$(OS) -DDEBUG -DMD_HAVE_EPOLL -DMALLOC_STACK
 # (but not too many!):
 # (but not too many!):
 # DEFINES += -DST_KEYS_MAX=<n>
 # DEFINES += -DST_KEYS_MAX=<n>
 #
 #
-# To start with more than the default 64 initial pollfd slots
-# (but the table grows dynamically anyway):
-# DEFINES += -DST_MIN_POLLFDS_SIZE=<n>
-#
 # Note that you can also add these defines by specifying them as
 # Note that you can also add these defines by specifying them as
 # make/gmake arguments (without editing this Makefile). For example:
 # make/gmake arguments (without editing this Makefile). For example:
 #
 #
-# make EXTRA_CFLAGS=-DUSE_POLL <target>
-#
-# (replace make with gmake if needed).
-#
-# You can also modify the default selection of an alternative event
-# notification mechanism. E.g., to enable kqueue(2) support (if it's not
-# enabled by default):
-#
-# gmake EXTRA_CFLAGS=-DMD_HAVE_KQUEUE <target>
-#
-# or to disable default epoll(4) support:
-#
 # make EXTRA_CFLAGS=-UMD_HAVE_EPOLL <target>
 # make EXTRA_CFLAGS=-UMD_HAVE_EPOLL <target>
 #
 #
 ##########################
 ##########################

@@ -40,985 +40,57 @@
 #include <errno.h>
 #include <errno.h>
 #include "common.h"
 #include "common.h"
 
 
-#ifdef MD_HAVE_KQUEUE
-#include <sys/event.h>
-#endif
-#ifdef MD_HAVE_EPOLL
-#include <sys/epoll.h>
-#endif
-
-#if defined(USE_POLL) && !defined(MD_HAVE_POLL)
-/* Force poll usage if explicitly asked for it */
-#define MD_HAVE_POLL
-#endif
-
-
-static struct _st_seldata {
-    fd_set fd_read_set, fd_write_set, fd_exception_set;
-    int fd_ref_cnts[FD_SETSIZE][3];
-    int maxfd;
-} *_st_select_data;
-
-#define _ST_SELECT_MAX_OSFD      (_st_select_data->maxfd)
-#define _ST_SELECT_READ_SET      (_st_select_data->fd_read_set)
-#define _ST_SELECT_WRITE_SET     (_st_select_data->fd_write_set)
-#define _ST_SELECT_EXCEP_SET     (_st_select_data->fd_exception_set)
-#define _ST_SELECT_READ_CNT(fd)  (_st_select_data->fd_ref_cnts[fd][0])
-#define _ST_SELECT_WRITE_CNT(fd) (_st_select_data->fd_ref_cnts[fd][1])
-#define _ST_SELECT_EXCEP_CNT(fd) (_st_select_data->fd_ref_cnts[fd][2])
-
-
-#ifdef MD_HAVE_POLL
-static struct _st_polldata {
-    struct pollfd *pollfds;
-    int pollfds_size;
-    int fdcnt;
-} *_st_poll_data;
-
-#define _ST_POLL_OSFD_CNT        (_st_poll_data->fdcnt) 
-#define _ST_POLLFDS              (_st_poll_data->pollfds) 
-#define _ST_POLLFDS_SIZE         (_st_poll_data->pollfds_size)
-#endif  /* MD_HAVE_POLL */
-
-
-#ifdef MD_HAVE_KQUEUE
-typedef struct _kq_fd_data {
-    int rd_ref_cnt;
-    int wr_ref_cnt;
-    int revents;
-} _kq_fd_data_t;
-
-static struct _st_kqdata {
-    _kq_fd_data_t *fd_data;
-    struct kevent *evtlist;
-    struct kevent *addlist;
-    struct kevent *dellist;
-    int fd_data_size;
-    int evtlist_size;
-    int addlist_size;
-    int addlist_cnt;
-    int dellist_size;
-    int dellist_cnt;
-    int kq;
-    pid_t pid;
-} *_st_kq_data;
-
-#ifndef ST_KQ_MIN_EVTLIST_SIZE
-#define ST_KQ_MIN_EVTLIST_SIZE 64
-#endif
-
-#define _ST_KQ_READ_CNT(fd)      (_st_kq_data->fd_data[fd].rd_ref_cnt)
-#define _ST_KQ_WRITE_CNT(fd)     (_st_kq_data->fd_data[fd].wr_ref_cnt)
-#define _ST_KQ_REVENTS(fd)       (_st_kq_data->fd_data[fd].revents)
-#endif  /* MD_HAVE_KQUEUE */
-
-
-#ifdef MD_HAVE_EPOLL
-typedef struct _epoll_fd_data {
-    int rd_ref_cnt;
-    int wr_ref_cnt;
-    int ex_ref_cnt;
-    int revents;
-} _epoll_fd_data_t;
-
-static struct _st_epolldata {
-    _epoll_fd_data_t *fd_data;
-    struct epoll_event *evtlist;
-    int fd_data_size;
-    int evtlist_size;
-    int evtlist_cnt;
-    int fd_hint;
-    int epfd;
-    pid_t pid;
-} *_st_epoll_data;
-
-#ifndef ST_EPOLL_EVTLIST_SIZE
-/* Not a limit, just a hint */
-#define ST_EPOLL_EVTLIST_SIZE 4096
-#endif
-
-#define _ST_EPOLL_READ_CNT(fd)   (_st_epoll_data->fd_data[fd].rd_ref_cnt)
-#define _ST_EPOLL_WRITE_CNT(fd)  (_st_epoll_data->fd_data[fd].wr_ref_cnt)
-#define _ST_EPOLL_EXCEP_CNT(fd)  (_st_epoll_data->fd_data[fd].ex_ref_cnt)
-#define _ST_EPOLL_REVENTS(fd)    (_st_epoll_data->fd_data[fd].revents)
-
-#define _ST_EPOLL_READ_BIT(fd)   (_ST_EPOLL_READ_CNT(fd) ? EPOLLIN : 0)
-#define _ST_EPOLL_WRITE_BIT(fd)  (_ST_EPOLL_WRITE_CNT(fd) ? EPOLLOUT : 0)
-#define _ST_EPOLL_EXCEP_BIT(fd)  (_ST_EPOLL_EXCEP_CNT(fd) ? EPOLLPRI : 0)
-#define _ST_EPOLL_EVENTS(fd) \
-    (_ST_EPOLL_READ_BIT(fd)|_ST_EPOLL_WRITE_BIT(fd)|_ST_EPOLL_EXCEP_BIT(fd))
-
-#endif  /* MD_HAVE_EPOLL */
-
-_st_eventsys_t *_st_eventsys = NULL;
-
-/*****************************************
- * select event system
- */
-
-ST_HIDDEN int _st_select_init(void)
-{
-    _st_select_data = (struct _st_seldata *) malloc(sizeof(*_st_select_data));
-    if (!_st_select_data) {
-        return -1;
-    }
-
-    memset(_st_select_data, 0, sizeof(*_st_select_data));
-    _st_select_data->maxfd = -1;
-
-    return 0;
-}
-
-ST_HIDDEN int _st_select_pollset_add(struct pollfd *pds, int npds)
-{
-    struct pollfd *pd;
-    struct pollfd *epd = pds + npds;
-
-    /* Do checks up front */
-    for (pd = pds; pd < epd; pd++) {
-        if (pd->fd < 0 || pd->fd >= FD_SETSIZE || !pd->events || (pd->events & ~(POLLIN | POLLOUT | POLLPRI))) {
-            errno = EINVAL;
-            return -1;
-        }
-    }
-
-    for (pd = pds; pd < epd; pd++) {
-        if (pd->events & POLLIN) {
-            FD_SET(pd->fd, &_ST_SELECT_READ_SET);
-            _ST_SELECT_READ_CNT(pd->fd)++;
-        }
-        if (pd->events & POLLOUT) {
-            FD_SET(pd->fd, &_ST_SELECT_WRITE_SET);
-            _ST_SELECT_WRITE_CNT(pd->fd)++;
-        }
-        if (pd->events & POLLPRI) {
-            FD_SET(pd->fd, &_ST_SELECT_EXCEP_SET);
-            _ST_SELECT_EXCEP_CNT(pd->fd)++;
-        }
-        if (_ST_SELECT_MAX_OSFD < pd->fd)
-            _ST_SELECT_MAX_OSFD = pd->fd;
-    }
-
-    return 0;
-}
-
-ST_HIDDEN void _st_select_pollset_del(struct pollfd *pds, int npds)
-{
-    struct pollfd *pd;
-    struct pollfd *epd = pds + npds;
-
-    for (pd = pds; pd < epd; pd++) {
-        if (pd->events & POLLIN) {
-            if (--_ST_SELECT_READ_CNT(pd->fd) == 0) {
-                FD_CLR(pd->fd, &_ST_SELECT_READ_SET);
-            }
-        }
-        if (pd->events & POLLOUT) {
-            if (--_ST_SELECT_WRITE_CNT(pd->fd) == 0) {
-                FD_CLR(pd->fd, &_ST_SELECT_WRITE_SET);
-            }
-        }
-        if (pd->events & POLLPRI) {
-            if (--_ST_SELECT_EXCEP_CNT(pd->fd) == 0) {
-                FD_CLR(pd->fd, &_ST_SELECT_EXCEP_SET);
-            }
-        }
-    }
-}
-
-ST_HIDDEN void _st_select_find_bad_fd(void)
-{
-    _st_clist_t *q;
-    _st_pollq_t *pq;
-    int notify;
-    struct pollfd *pds, *epds;
-    int pq_max_osfd, osfd;
-    short events;
-
-    _ST_SELECT_MAX_OSFD = -1;
-
-    for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
-        pq = _ST_POLLQUEUE_PTR(q);
-        notify = 0;
-        epds = pq->pds + pq->npds;
-        pq_max_osfd = -1;
-      
-        for (pds = pq->pds; pds < epds; pds++) {
-            osfd = pds->fd;
-            pds->revents = 0;
-            if (pds->events == 0) {
-                continue;
-            }
-            if (fcntl(osfd, F_GETFL, 0) < 0) {
-                pds->revents = POLLNVAL;
-                notify = 1;
-            }
-            if (osfd > pq_max_osfd) {
-                pq_max_osfd = osfd;
-            }
-        }
-
-        if (notify) {
-            ST_REMOVE_LINK(&pq->links);
-            pq->on_ioq = 0;
-            /*
-             * Decrement the count of descriptors for each descriptor/event
-             * because this I/O request is being removed from the ioq
-             */
-            for (pds = pq->pds; pds < epds; pds++) {
-                osfd = pds->fd;
-                events = pds->events;
-                if (events & POLLIN) {
-                    if (--_ST_SELECT_READ_CNT(osfd) == 0) {
-                        FD_CLR(osfd, &_ST_SELECT_READ_SET);
-                    }
-                }
-                if (events & POLLOUT) {
-                    if (--_ST_SELECT_WRITE_CNT(osfd) == 0) {
-                        FD_CLR(osfd, &_ST_SELECT_WRITE_SET);
-                    }
-                }
-                if (events & POLLPRI) {
-                    if (--_ST_SELECT_EXCEP_CNT(osfd) == 0) {
-                        FD_CLR(osfd, &_ST_SELECT_EXCEP_SET);
-                    }
-                }
-            }
-
-            if (pq->thread->flags & _ST_FL_ON_SLEEPQ) {
-                _ST_DEL_SLEEPQ(pq->thread);
-            }
-            pq->thread->state = _ST_ST_RUNNABLE;
-            _ST_ADD_RUNQ(pq->thread);
-        } else {
-            if (_ST_SELECT_MAX_OSFD < pq_max_osfd) {
-                _ST_SELECT_MAX_OSFD = pq_max_osfd;
-            }
-        }
-    }
-}
-
-ST_HIDDEN void _st_select_dispatch(void)
-{
-    struct timeval timeout, *tvp;
-    fd_set r, w, e;
-    fd_set *rp, *wp, *ep;
-    int nfd, pq_max_osfd, osfd;
-    _st_clist_t *q;
-    st_utime_t min_timeout;
-    _st_pollq_t *pq;
-    int notify;
-    struct pollfd *pds, *epds;
-    short events, revents;
-
-    /*
-     * Assignment of fd_sets
-     */
-    r = _ST_SELECT_READ_SET;
-    w = _ST_SELECT_WRITE_SET;
-    e = _ST_SELECT_EXCEP_SET;
-
-    rp = &r;
-    wp = &w;
-    ep = &e;
-
-    if (_ST_SLEEPQ == NULL) {
-        tvp = NULL;
-    } else {
-        min_timeout = (_ST_SLEEPQ->due <= _ST_LAST_CLOCK) ? 0 : (_ST_SLEEPQ->due - _ST_LAST_CLOCK);
-        timeout.tv_sec  = (int) (min_timeout / 1000000);
-        timeout.tv_usec = (int) (min_timeout % 1000000);
-        tvp = &timeout;
-    }
-
-    /* Check for I/O operations */
-    nfd = select(_ST_SELECT_MAX_OSFD + 1, rp, wp, ep, tvp);
-
-    /* Notify threads that are associated with the selected descriptors */
-    if (nfd > 0) {
-        _ST_SELECT_MAX_OSFD = -1;
-        for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
-            pq = _ST_POLLQUEUE_PTR(q);
-            notify = 0;
-            epds = pq->pds + pq->npds;
-            pq_max_osfd = -1;
-      
-            for (pds = pq->pds; pds < epds; pds++) {
-                osfd = pds->fd;
-                events = pds->events;
-                revents = 0;
-                if ((events & POLLIN) && FD_ISSET(osfd, rp)) {
-                    revents |= POLLIN;
-                }
-                if ((events & POLLOUT) && FD_ISSET(osfd, wp)) {
-                    revents |= POLLOUT;
-                }
-                if ((events & POLLPRI) && FD_ISSET(osfd, ep)) {
-                    revents |= POLLPRI;
-                }
-                pds->revents = revents;
-                if (revents) {
-                    notify = 1;
-                }
-                if (osfd > pq_max_osfd) {
-                    pq_max_osfd = osfd;
-                }
-            }
-            if (notify) {
-                ST_REMOVE_LINK(&pq->links);
-                pq->on_ioq = 0;
-                /*
-                 * Decrement the count of descriptors for each descriptor/event
-                 * because this I/O request is being removed from the ioq
-                 */
-                for (pds = pq->pds; pds < epds; pds++) {
-                    osfd = pds->fd;
-                    events = pds->events;
-                    if (events & POLLIN) {
-                        if (--_ST_SELECT_READ_CNT(osfd) == 0) {
-                            FD_CLR(osfd, &_ST_SELECT_READ_SET);
-                        }
-                    }
-                    if (events & POLLOUT) {
-                        if (--_ST_SELECT_WRITE_CNT(osfd) == 0) {
-                            FD_CLR(osfd, &_ST_SELECT_WRITE_SET);
-                        }
-                    }
-                    if (events & POLLPRI) {
-                        if (--_ST_SELECT_EXCEP_CNT(osfd) == 0) {
-                            FD_CLR(osfd, &_ST_SELECT_EXCEP_SET);
-                        }
-                    }
-                }
-
-                if (pq->thread->flags & _ST_FL_ON_SLEEPQ) {
-                    _ST_DEL_SLEEPQ(pq->thread);
-                }
-                pq->thread->state = _ST_ST_RUNNABLE;
-                _ST_ADD_RUNQ(pq->thread);
-            } else {
-                if (_ST_SELECT_MAX_OSFD < pq_max_osfd) {
-                    _ST_SELECT_MAX_OSFD = pq_max_osfd;
-                }
-            }
-        }
-    } else if (nfd < 0) {
-        /*
-         * It can happen when a thread closes file descriptor
-         * that is being used by some other thread -- BAD!
-         */
-        if (errno == EBADF) {
-            _st_select_find_bad_fd();
-        }
-    }
-}
-
-ST_HIDDEN int _st_select_fd_new(int osfd)
-{
-    if (osfd >= FD_SETSIZE) {
-        errno = EMFILE;
-        return -1;
-    }
-
-    return 0;
-}
-
-ST_HIDDEN int _st_select_fd_close(int osfd)
-{
-    if (_ST_SELECT_READ_CNT(osfd) || _ST_SELECT_WRITE_CNT(osfd) || _ST_SELECT_EXCEP_CNT(osfd)) {
-        errno = EBUSY;
-        return -1;
-    }
-
-    return 0;
-}
-
-ST_HIDDEN int _st_select_fd_getlimit(void)
-{
-    return FD_SETSIZE;
-}
-
-static _st_eventsys_t _st_select_eventsys = {
-    "select",
-    ST_EVENTSYS_SELECT,
-    _st_select_init,
-    _st_select_dispatch,
-    _st_select_pollset_add,
-    _st_select_pollset_del,
-    _st_select_fd_new,
-    _st_select_fd_close,
-    _st_select_fd_getlimit
-};
-
-#ifdef MD_HAVE_POLL
-/*****************************************
- * poll event system
- */
-
-ST_HIDDEN int _st_poll_init(void)
-{
-    _st_poll_data = (struct _st_polldata *) malloc(sizeof(*_st_poll_data));
-    if (!_st_poll_data) {
-        return -1;
-    }
-
-    _ST_POLLFDS = (struct pollfd *) malloc(ST_MIN_POLLFDS_SIZE * sizeof(struct pollfd));
-    if (!_ST_POLLFDS) {
-        free(_st_poll_data);
-        _st_poll_data = NULL;
-        return -1;
-    }
-    _ST_POLLFDS_SIZE = ST_MIN_POLLFDS_SIZE;
-    _ST_POLL_OSFD_CNT = 0;
-
-    return 0;
-}
-
-ST_HIDDEN int _st_poll_pollset_add(struct pollfd *pds, int npds)
-{
-    struct pollfd *pd;
-    struct pollfd *epd = pds + npds;
-
-    for (pd = pds; pd < epd; pd++) {
-        if (pd->fd < 0 || !pd->events) {
-            errno = EINVAL;
-            return -1;
-        }
-    }
-
-    _ST_POLL_OSFD_CNT += npds;
-
-    return 0;
-}
-
-/* ARGSUSED */
-ST_HIDDEN void _st_poll_pollset_del(struct pollfd *pds, int npds)
-{
-    _ST_POLL_OSFD_CNT -= npds;
-    ST_ASSERT(_ST_POLL_OSFD_CNT >= 0);
-}
-
-ST_HIDDEN void _st_poll_dispatch(void)
-{
-    int timeout, nfd;
-    _st_clist_t *q;
-    st_utime_t min_timeout;
-    _st_pollq_t *pq;
-    struct pollfd *pds, *epds, *pollfds;
-
-    /*
-     * Build up the array of struct pollfd to wait on.
-     * If existing array is not big enough, release it and allocate a new one.
-     */
-    ST_ASSERT(_ST_POLL_OSFD_CNT >= 0);
-    if (_ST_POLL_OSFD_CNT > _ST_POLLFDS_SIZE) {
-        free(_ST_POLLFDS);
-        _ST_POLLFDS = (struct pollfd *) malloc((_ST_POLL_OSFD_CNT + 10) * sizeof(struct pollfd));
-        ST_ASSERT(_ST_POLLFDS != NULL);
-        _ST_POLLFDS_SIZE = _ST_POLL_OSFD_CNT + 10;
-    }
-    pollfds = _ST_POLLFDS;
-
-    /* Gather all descriptors into one array */
-    for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
-        pq = _ST_POLLQUEUE_PTR(q);
-        memcpy(pollfds, pq->pds, sizeof(struct pollfd) * pq->npds);
-        pollfds += pq->npds;
-    }
-    ST_ASSERT(pollfds <= _ST_POLLFDS + _ST_POLLFDS_SIZE);
-
-    if (_ST_SLEEPQ == NULL) {
-        timeout = -1;
-    } else {
-        min_timeout = (_ST_SLEEPQ->due <= _ST_LAST_CLOCK) ? 0 : (_ST_SLEEPQ->due - _ST_LAST_CLOCK);
-        timeout = (int) (min_timeout / 1000);
-    }
-
-    /* Check for I/O operations */
-    nfd = poll(_ST_POLLFDS, _ST_POLL_OSFD_CNT, timeout);
-
-    /* Notify threads that are associated with the selected descriptors */
-    if (nfd > 0) {
-        pollfds = _ST_POLLFDS;
-        for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
-            pq = _ST_POLLQUEUE_PTR(q);
-            epds = pollfds + pq->npds;
-            for (pds = pollfds; pds < epds; pds++) {
-                if (pds->revents) {
-                    break;
-                }
-            }
-            if (pds < epds) {
-                memcpy(pq->pds, pollfds, sizeof(struct pollfd) * pq->npds);
-                ST_REMOVE_LINK(&pq->links);
-                pq->on_ioq = 0;
-
-                if (pq->thread->flags & _ST_FL_ON_SLEEPQ) {
-                    _ST_DEL_SLEEPQ(pq->thread);
-                }
-                pq->thread->state = _ST_ST_RUNNABLE;
-                _ST_ADD_RUNQ(pq->thread);
-
-                _ST_POLL_OSFD_CNT -= pq->npds;
-                ST_ASSERT(_ST_POLL_OSFD_CNT >= 0);
-            }
-            pollfds = epds;
-        }
-    }
-}
-
-/* ARGSUSED */
-ST_HIDDEN int _st_poll_fd_new(int osfd)
-{
-    return 0;
-}
-
-/* ARGSUSED */
-ST_HIDDEN int _st_poll_fd_close(int osfd)
-{
-    /*
-     * We don't maintain I/O counts for poll event system
-     * so nothing to check here.
-     */
-    return 0;
-}
-
-ST_HIDDEN int _st_poll_fd_getlimit(void)
-{
-    /* zero means no specific limit */
-    return 0;
-}
-
-static _st_eventsys_t _st_poll_eventsys = {
-    "poll",
-    ST_EVENTSYS_POLL,
-    _st_poll_init,
-    _st_poll_dispatch,
-    _st_poll_pollset_add,
-    _st_poll_pollset_del,
-    _st_poll_fd_new,
-    _st_poll_fd_close,
-    _st_poll_fd_getlimit
-};
-#endif  /* MD_HAVE_POLL */
-
-
-#ifdef MD_HAVE_KQUEUE
-/*****************************************
- * kqueue event system
- */
-                    
-ST_HIDDEN int _st_kq_init(void)
-{
-    int err = 0;
-    int rv = 0;
-
-    _st_kq_data = (struct _st_kqdata *) calloc(1, sizeof(*_st_kq_data));
-    if (!_st_kq_data) {
-        return -1;
-    }
-
-    if ((_st_kq_data->kq = kqueue()) < 0) {
-        err = errno;
-        rv = -1;
-        goto cleanup_kq;
-    }
-    fcntl(_st_kq_data->kq, F_SETFD, FD_CLOEXEC);
-    _st_kq_data->pid = getpid();
-
-    /*
-     * Allocate file descriptor data array.
-     * FD_SETSIZE looks like good initial size.
-     */
-    _st_kq_data->fd_data_size = FD_SETSIZE;
-    _st_kq_data->fd_data = (_kq_fd_data_t *)calloc(_st_kq_data->fd_data_size, sizeof(_kq_fd_data_t));
-    if (!_st_kq_data->fd_data) {
-        err = errno;
-        rv = -1;
-        goto cleanup_kq;
-    }
-
-    /* Allocate event lists */
-    _st_kq_data->evtlist_size = ST_KQ_MIN_EVTLIST_SIZE;
-    _st_kq_data->evtlist = (struct kevent *)malloc(_st_kq_data->evtlist_size * sizeof(struct kevent));
-    _st_kq_data->addlist_size = ST_KQ_MIN_EVTLIST_SIZE;
-    _st_kq_data->addlist = (struct kevent *)malloc(_st_kq_data->addlist_size * sizeof(struct kevent));
-    _st_kq_data->dellist_size = ST_KQ_MIN_EVTLIST_SIZE;
-    _st_kq_data->dellist = (struct kevent *)malloc(_st_kq_data->dellist_size * sizeof(struct kevent));
-    if (!_st_kq_data->evtlist || !_st_kq_data->addlist ||
-        !_st_kq_data->dellist) {
-        err = ENOMEM;
-        rv = -1;
-    }
-
- cleanup_kq:
-    if (rv < 0) {
-        if (_st_kq_data->kq >= 0) {
-            close(_st_kq_data->kq);
-        }
-        free(_st_kq_data->fd_data);
-        free(_st_kq_data->evtlist);
-        free(_st_kq_data->addlist);
-        free(_st_kq_data->dellist);
-        free(_st_kq_data);
-        _st_kq_data = NULL;
-        errno = err;
-    }
-
-    return rv;
-}
-
-ST_HIDDEN int _st_kq_fd_data_expand(int maxfd)
-{
-    _kq_fd_data_t *ptr;
-    int n = _st_kq_data->fd_data_size;
-
-    while (maxfd >= n) {
-        n <<= 1;
-    }
-
-    ptr = (_kq_fd_data_t *)realloc(_st_kq_data->fd_data, n * sizeof(_kq_fd_data_t));
-    if (!ptr) {
-        return -1;
-    }
-
-    memset(ptr + _st_kq_data->fd_data_size, 0, (n - _st_kq_data->fd_data_size) * sizeof(_kq_fd_data_t));
-
-    _st_kq_data->fd_data = ptr;
-    _st_kq_data->fd_data_size = n;
-
-    return 0;
-}
-
-ST_HIDDEN int _st_kq_addlist_expand(int avail)
-{
-    struct kevent *ptr;
-    int n = _st_kq_data->addlist_size;
-
-    while (avail > n - _st_kq_data->addlist_cnt) {
-        n <<= 1;
-    }
-
-    ptr = (struct kevent *)realloc(_st_kq_data->addlist, n * sizeof(struct kevent));
-    if (!ptr) {
-        return -1;
-    }
-
-    _st_kq_data->addlist = ptr;
-    _st_kq_data->addlist_size = n;
-
-    /*
-     * Try to expand the result event list too
-     * (although we don't have to do it).
-     */
-    ptr = (struct kevent *)realloc(_st_kq_data->evtlist, n * sizeof(struct kevent));
-    if (ptr) {
-        _st_kq_data->evtlist = ptr;
-        _st_kq_data->evtlist_size = n;
-    }
-
-    return 0;
-}
-
-ST_HIDDEN void _st_kq_addlist_add(const struct kevent *kev)
-{
-    ST_ASSERT(_st_kq_data->addlist_cnt < _st_kq_data->addlist_size);
-    memcpy(_st_kq_data->addlist + _st_kq_data->addlist_cnt, kev, sizeof(struct kevent));
-    _st_kq_data->addlist_cnt++;
-}
-
-ST_HIDDEN void _st_kq_dellist_add(const struct kevent *kev)
-{
-    int n = _st_kq_data->dellist_size;
-
-    if (_st_kq_data->dellist_cnt >= n) {
-        struct kevent *ptr;
-
-        n <<= 1;
-        ptr = (struct kevent *)realloc(_st_kq_data->dellist, n * sizeof(struct kevent));
-        if (!ptr) {
-            /* See comment in _st_kq_pollset_del() */
-            return;
-        }
-
-        _st_kq_data->dellist = ptr;
-        _st_kq_data->dellist_size = n;
-    }
-
-    memcpy(_st_kq_data->dellist + _st_kq_data->dellist_cnt, kev, sizeof(struct kevent));
-    _st_kq_data->dellist_cnt++;
-}
-
-ST_HIDDEN int _st_kq_pollset_add(struct pollfd *pds, int npds)
-{
-    struct kevent kev;
-    struct pollfd *pd;
-    struct pollfd *epd = pds + npds;
-
-    /*
-     * Pollset adding is "atomic". That is, either it succeeded for
-     * all descriptors in the set or it failed. It means that we
-     * need to do all the checks up front so we don't have to
-     * "unwind" if adding of one of the descriptors failed.
-     */
-    for (pd = pds; pd < epd; pd++) {
-        /* POLLIN and/or POLLOUT must be set, but nothing else */
-        if (pd->fd < 0 || !pd->events || (pd->events & ~(POLLIN | POLLOUT))) {
-            errno = EINVAL;
-            return -1;
-        }
-        if (pd->fd >= _st_kq_data->fd_data_size && _st_kq_fd_data_expand(pd->fd) < 0) {
-            return -1;
-        }
-    }
-
-    /*
-     * Make sure we have enough room in the addlist for twice as many
-     * descriptors as in the pollset (for both READ and WRITE filters).
-     */
-    npds <<= 1;
-    if (npds > _st_kq_data->addlist_size - _st_kq_data->addlist_cnt && _st_kq_addlist_expand(npds) < 0) {
-        return -1;
-    }
-
-    for (pd = pds; pd < epd; pd++) {
-        if ((pd->events & POLLIN) && (_ST_KQ_READ_CNT(pd->fd)++ == 0)) {
-            memset(&kev, 0, sizeof(kev));
-            kev.ident = pd->fd;
-            kev.filter = EVFILT_READ;
-#ifdef NOTE_EOF
-            /* Make it behave like select() and poll() */
-            kev.fflags = NOTE_EOF;
+#ifdef USE_POLL
+    #error "Not support USE_POLL"
+#endif
+#ifdef MD_HAVE_KQUEUE
+    #error "Not support MD_HAVE_KQUEUE"
+#endif
+#ifdef MD_HAVE_POLL
+    #error "Not support MD_HAVE_POLL"
+#endif
+#ifndef MD_HAVE_EPOLL
+    #error "Only support MD_HAVE_EPOLL"
 #endif
 #endif
-            kev.flags = (EV_ADD | EV_ONESHOT);
-            _st_kq_addlist_add(&kev);
-        }
-        if ((pd->events & POLLOUT) && (_ST_KQ_WRITE_CNT(pd->fd)++ == 0)) {
-            memset(&kev, 0, sizeof(kev));
-            kev.ident = pd->fd;
-            kev.filter = EVFILT_WRITE;
-            kev.flags = (EV_ADD | EV_ONESHOT);
-            _st_kq_addlist_add(&kev);
-        }
-    }
-
-    return 0;
-}
-
-ST_HIDDEN void _st_kq_pollset_del(struct pollfd *pds, int npds)
-{
-    struct kevent kev;
-    struct pollfd *pd;
-    struct pollfd *epd = pds + npds;
-
-    /*
-     * It's OK if deleting fails because a descriptor will either be
-     * closed or fire only once (we set EV_ONESHOT flag).
-     */
-    _st_kq_data->dellist_cnt = 0;
-    for (pd = pds; pd < epd; pd++) {
-        if ((pd->events & POLLIN) && (--_ST_KQ_READ_CNT(pd->fd) == 0)) {
-            memset(&kev, 0, sizeof(kev));
-            kev.ident = pd->fd;
-            kev.filter = EVFILT_READ;
-            kev.flags = EV_DELETE;
-            _st_kq_dellist_add(&kev);
-        }
-        if ((pd->events & POLLOUT) && (--_ST_KQ_WRITE_CNT(pd->fd) == 0)) {
-            memset(&kev, 0, sizeof(kev));
-            kev.ident = pd->fd;
-            kev.filter = EVFILT_WRITE;
-            kev.flags = EV_DELETE;
-            _st_kq_dellist_add(&kev);
-        }
-    }
-
-    if (_st_kq_data->dellist_cnt > 0) {
-        /*
-         * We do "synchronous" kqueue deletes to avoid deleting
-         * closed descriptors and other possible problems.
-         */
-        int rv;
-        do {
-            /* This kevent() won't block since result list size is 0 */
-            rv = kevent(_st_kq_data->kq, _st_kq_data->dellist, _st_kq_data->dellist_cnt, NULL, 0, NULL);
-        } while (rv < 0 && errno == EINTR);
-    }
-}
-
-ST_HIDDEN void _st_kq_dispatch(void)
-{
-    struct timespec timeout, *tsp;
-    struct kevent kev;
-    st_utime_t min_timeout;
-    _st_clist_t *q;
-    _st_pollq_t *pq;
-    struct pollfd *pds, *epds;
-    int nfd, i, osfd, notify, filter;
-    short events, revents;
-
-    if (_ST_SLEEPQ == NULL) {
-        tsp = NULL;
-    } else {
-        min_timeout = (_ST_SLEEPQ->due <= _ST_LAST_CLOCK) ? 0 : (_ST_SLEEPQ->due - _ST_LAST_CLOCK);
-        timeout.tv_sec  = (time_t) (min_timeout / 1000000);
-        timeout.tv_nsec = (long) ((min_timeout % 1000000) * 1000);
-        tsp = &timeout;
-    }
-
- retry_kevent:
-    /* Check for I/O operations */
-    nfd = kevent(_st_kq_data->kq, _st_kq_data->addlist, _st_kq_data->addlist_cnt, 
-        _st_kq_data->evtlist, _st_kq_data->evtlist_size, tsp);
-
-    _st_kq_data->addlist_cnt = 0;
-
-    if (nfd > 0) {
-        for (i = 0; i < nfd; i++) {
-            osfd = _st_kq_data->evtlist[i].ident;
-            filter = _st_kq_data->evtlist[i].filter;
-
-            if (filter == EVFILT_READ) {
-                _ST_KQ_REVENTS(osfd) |= POLLIN;
-            } else if (filter == EVFILT_WRITE) {
-                _ST_KQ_REVENTS(osfd) |= POLLOUT;
-            }
-            if (_st_kq_data->evtlist[i].flags & EV_ERROR) {
-                if (_st_kq_data->evtlist[i].data == EBADF) {
-                    _ST_KQ_REVENTS(osfd) |= POLLNVAL;
-                } else {
-                    _ST_KQ_REVENTS(osfd) |= POLLERR;
-                }
-            }
-        }
-
-        _st_kq_data->dellist_cnt = 0;
-
-        for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
-            pq = _ST_POLLQUEUE_PTR(q);
-            notify = 0;
-            epds = pq->pds + pq->npds;
-                     
-            for (pds = pq->pds; pds < epds; pds++) {
-                osfd = pds->fd;
-                events = pds->events;
-                revents = (short)(_ST_KQ_REVENTS(osfd) & ~(POLLIN | POLLOUT));
-                if ((events & POLLIN) && (_ST_KQ_REVENTS(osfd) & POLLIN)) {
-                    revents |= POLLIN;
-                }
-                if ((events & POLLOUT) && (_ST_KQ_REVENTS(osfd) & POLLOUT)) {
-                    revents |= POLLOUT;
-                }
-                pds->revents = revents;
-                if (revents) {
-                    notify = 1;
-                }
-            }
-            if (notify) {
-                ST_REMOVE_LINK(&pq->links);
-                pq->on_ioq = 0;
-                for (pds = pq->pds; pds < epds; pds++) {
-                    osfd = pds->fd;
-                    events = pds->events;
-                    /*
-                     * We set EV_ONESHOT flag so we only need to delete
-                     * descriptor if it didn't fire.
-                     */
-                    if ((events & POLLIN) && (--_ST_KQ_READ_CNT(osfd) == 0) && ((_ST_KQ_REVENTS(osfd) & POLLIN) == 0)) {
-                        memset(&kev, 0, sizeof(kev));
-                        kev.ident = osfd;
-                        kev.filter = EVFILT_READ;
-                        kev.flags = EV_DELETE;
-                        _st_kq_dellist_add(&kev);
-                    }
-                    if ((events & POLLOUT) && (--_ST_KQ_WRITE_CNT(osfd) == 0) && ((_ST_KQ_REVENTS(osfd) & POLLOUT) == 0)) {
-                        memset(&kev, 0, sizeof(kev));
-                        kev.ident = osfd;
-                        kev.filter = EVFILT_WRITE;
-                        kev.flags = EV_DELETE;
-                        _st_kq_dellist_add(&kev);
-                    }
-                }
-
-                if (pq->thread->flags & _ST_FL_ON_SLEEPQ) {
-                    _ST_DEL_SLEEPQ(pq->thread);
-                }
-                pq->thread->state = _ST_ST_RUNNABLE;
-                _ST_ADD_RUNQ(pq->thread);
-            }
-        }
-
-        if (_st_kq_data->dellist_cnt > 0) {
-            int rv;
-            do {
-                /* This kevent() won't block since result list size is 0 */
-                rv = kevent(_st_kq_data->kq, _st_kq_data->dellist, _st_kq_data->dellist_cnt, NULL, 0, NULL);
-            } while (rv < 0 && errno == EINTR);
-        }
 
 
-        for (i = 0; i < nfd; i++) {
-            osfd = _st_kq_data->evtlist[i].ident;
-            _ST_KQ_REVENTS(osfd) = 0;
-        }
-    } else if (nfd < 0) {
-        if (errno == EBADF && _st_kq_data->pid != getpid()) {
-            /* We probably forked, reinitialize kqueue */
-            if ((_st_kq_data->kq = kqueue()) < 0) {
-                /* There is nothing we can do here, will retry later */
-                return;
-            }
-            fcntl(_st_kq_data->kq, F_SETFD, FD_CLOEXEC);
-            _st_kq_data->pid = getpid();
-            /* Re-register all descriptors on ioq with new kqueue */
-            memset(_st_kq_data->fd_data, 0, _st_kq_data->fd_data_size * sizeof(_kq_fd_data_t));
-            for (q = _ST_IOQ.next; q != &_ST_IOQ; q = q->next) {
-                pq = _ST_POLLQUEUE_PTR(q);
-                _st_kq_pollset_add(pq->pds, pq->npds);
-            }
-            goto retry_kevent;
-        }
-    }
-}
+#include <sys/epoll.h>
 
 
-ST_HIDDEN int _st_kq_fd_new(int osfd)
-{
-    if (osfd >= _st_kq_data->fd_data_size && _st_kq_fd_data_expand(osfd) < 0) {
-        return -1;
-    }
+typedef struct _epoll_fd_data {
+    int rd_ref_cnt;
+    int wr_ref_cnt;
+    int ex_ref_cnt;
+    int revents;
+} _epoll_fd_data_t;
 
 
-    return 0;
-}
+static struct _st_epolldata {
+    _epoll_fd_data_t *fd_data;
+    struct epoll_event *evtlist;
+    int fd_data_size;
+    int evtlist_size;
+    int evtlist_cnt;
+    int fd_hint;
+    int epfd;
+    pid_t pid;
+} *_st_epoll_data;
 
 
-ST_HIDDEN int _st_kq_fd_close(int osfd)
-{
-    if (_ST_KQ_READ_CNT(osfd) || _ST_KQ_WRITE_CNT(osfd)) {
-        errno = EBUSY;
-        return -1;
-    }
+#ifndef ST_EPOLL_EVTLIST_SIZE
+/* Not a limit, just a hint */
+#define ST_EPOLL_EVTLIST_SIZE 4096
+#endif
 
 
-    return 0;
-}
+#define _ST_EPOLL_READ_CNT(fd)   (_st_epoll_data->fd_data[fd].rd_ref_cnt)
+#define _ST_EPOLL_WRITE_CNT(fd)  (_st_epoll_data->fd_data[fd].wr_ref_cnt)
+#define _ST_EPOLL_EXCEP_CNT(fd)  (_st_epoll_data->fd_data[fd].ex_ref_cnt)
+#define _ST_EPOLL_REVENTS(fd)    (_st_epoll_data->fd_data[fd].revents)
 
 
-ST_HIDDEN int _st_kq_fd_getlimit(void)
-{
-    /* zero means no specific limit */
-    return 0;
-}
+#define _ST_EPOLL_READ_BIT(fd)   (_ST_EPOLL_READ_CNT(fd) ? EPOLLIN : 0)
+#define _ST_EPOLL_WRITE_BIT(fd)  (_ST_EPOLL_WRITE_CNT(fd) ? EPOLLOUT : 0)
+#define _ST_EPOLL_EXCEP_BIT(fd)  (_ST_EPOLL_EXCEP_CNT(fd) ? EPOLLPRI : 0)
+#define _ST_EPOLL_EVENTS(fd) \
+    (_ST_EPOLL_READ_BIT(fd)|_ST_EPOLL_WRITE_BIT(fd)|_ST_EPOLL_EXCEP_BIT(fd))
 
 
-static _st_eventsys_t _st_kq_eventsys = {
-    "kqueue",
-    ST_EVENTSYS_ALT,
-    _st_kq_init,
-    _st_kq_dispatch,
-    _st_kq_pollset_add,
-    _st_kq_pollset_del,
-    _st_kq_fd_new,
-    _st_kq_fd_close,  
-    _st_kq_fd_getlimit
-};
-#endif  /* MD_HAVE_KQUEUE */
+_st_eventsys_t *_st_eventsys = NULL;
 
 
-#ifdef MD_HAVE_EPOLL
 /*****************************************
 /*****************************************
  * epoll event system
  * epoll event system
  */
  */
@@ -1386,8 +458,6 @@ static _st_eventsys_t _st_epoll_eventsys = {
     _st_epoll_fd_close,
     _st_epoll_fd_close,
     _st_epoll_fd_getlimit
     _st_epoll_fd_getlimit
 };
 };
-#endif  /* MD_HAVE_EPOLL */
-
 
 
 /*****************************************
 /*****************************************
  * Public functions
  * Public functions
@@ -1402,30 +472,12 @@ int st_set_eventsys(int eventsys)
 
 
     switch (eventsys) {
     switch (eventsys) {
     case ST_EVENTSYS_DEFAULT:
     case ST_EVENTSYS_DEFAULT:
-#ifdef USE_POLL
-        _st_eventsys = &_st_poll_eventsys;
-#else
-        _st_eventsys = &_st_select_eventsys;
-#endif
-        break;
-    case ST_EVENTSYS_SELECT:
-        _st_eventsys = &_st_select_eventsys;
-        break;
-#ifdef MD_HAVE_POLL
-    case ST_EVENTSYS_POLL:
-        _st_eventsys = &_st_poll_eventsys;
-        break;
-#endif
     case ST_EVENTSYS_ALT:
     case ST_EVENTSYS_ALT:
-#if defined (MD_HAVE_KQUEUE)
-        _st_eventsys = &_st_kq_eventsys;
-#elif defined (MD_HAVE_EPOLL)
+    default:
         if (_st_epoll_is_supported()) {
         if (_st_epoll_is_supported()) {
             _st_eventsys = &_st_epoll_eventsys;
             _st_eventsys = &_st_epoll_eventsys;
-        }
-#endif
             break;
             break;
-    default:
+        }
         errno = EINVAL;
         errno = EINVAL;
         return -1;
         return -1;
     }
     }

@@ -177,10 +177,6 @@
 /*****************************************
 /*****************************************
  * Other defines
  * Other defines
  */
  */
-#if !defined(MD_HAVE_POLL) && !defined(MD_DONT_HAVE_POLL)
-    #define MD_HAVE_POLL
-#endif
-
 #ifndef MD_STACK_PAD_SIZE
 #ifndef MD_STACK_PAD_SIZE
     #define MD_STACK_PAD_SIZE 128
     #define MD_STACK_PAD_SIZE 128
 #endif
 #endif