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-rw-r--r--epoll.c369
1 files changed, 369 insertions, 0 deletions
diff --git a/epoll.c b/epoll.c
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+++ b/epoll.c
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+/*
+ * Copyright 2000-2003 Niels Provos <provos@citi.umich.edu>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/resource.h>
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#else
+#include <sys/_time.h>
+#endif
+#include <sys/queue.h>
+#include <sys/epoll.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#include "event.h"
+#include "evsignal.h"
+#include "log.h"
+
+extern volatile sig_atomic_t evsignal_caught;
+
+/* due to limitations in the epoll interface, we need to keep track of
+ * all file descriptors outself.
+ */
+struct evepoll {
+ struct event *evread;
+ struct event *evwrite;
+};
+
+struct epollop {
+ struct evepoll *fds;
+ int nfds;
+ struct epoll_event *events;
+ int nevents;
+ int epfd;
+ sigset_t evsigmask;
+};
+
+void *epoll_init (void);
+int epoll_add (void *, struct event *);
+int epoll_del (void *, struct event *);
+int epoll_recalc (struct event_base *, void *, int);
+int epoll_dispatch (struct event_base *, void *, struct timeval *);
+void epoll_dealloc (void *);
+
+struct eventop epollops = {
+ "epoll",
+ epoll_init,
+ epoll_add,
+ epoll_del,
+ epoll_recalc,
+ epoll_dispatch,
+ epoll_dealloc
+};
+
+#ifdef HAVE_SETFD
+#define FD_CLOSEONEXEC(x) do { \
+ if (fcntl(x, F_SETFD, 1) == -1) \
+ event_warn("fcntl(%d, F_SETFD)", x); \
+} while (0)
+#else
+#define FD_CLOSEONEXEC(x)
+#endif
+
+#define NEVENT 32000
+
+void *
+epoll_init(void)
+{
+ int epfd, nfiles = NEVENT;
+ struct rlimit rl;
+ struct epollop *epollop;
+
+ /* Disable epollueue when this environment variable is set */
+ if (getenv("EVENT_NOEPOLL"))
+ return (NULL);
+
+ if (getrlimit(RLIMIT_NOFILE, &rl) == 0 &&
+ rl.rlim_cur != RLIM_INFINITY) {
+ /*
+ * Solaris is somewhat retarded - it's important to drop
+ * backwards compatibility when making changes. So, don't
+ * dare to put rl.rlim_cur here.
+ */
+ nfiles = rl.rlim_cur - 1;
+ }
+
+ /* Initalize the kernel queue */
+
+ if ((epfd = epoll_create(nfiles)) == -1) {
+ event_warn("epoll_create");
+ return (NULL);
+ }
+
+ FD_CLOSEONEXEC(epfd);
+
+ if (!(epollop = calloc(1, sizeof(struct epollop))))
+ return (NULL);
+
+ epollop->epfd = epfd;
+
+ /* Initalize fields */
+ epollop->events = malloc(nfiles * sizeof(struct epoll_event));
+ if (epollop->events == NULL) {
+ free(epollop);
+ return (NULL);
+ }
+ epollop->nevents = nfiles;
+
+ epollop->fds = calloc(nfiles, sizeof(struct evepoll));
+ if (epollop->fds == NULL) {
+ free(epollop->events);
+ free(epollop);
+ return (NULL);
+ }
+ epollop->nfds = nfiles;
+
+ evsignal_init(&epollop->evsigmask);
+
+ return (epollop);
+}
+
+int
+epoll_recalc(struct event_base *base, void *arg, int max)
+{
+ struct epollop *epollop = arg;
+
+ if (max > epollop->nfds) {
+ struct evepoll *fds;
+ int nfds;
+
+ nfds = epollop->nfds;
+ while (nfds < max)
+ nfds <<= 1;
+
+ fds = realloc(epollop->fds, nfds * sizeof(struct evepoll));
+ if (fds == NULL) {
+ event_warn("realloc");
+ return (-1);
+ }
+ epollop->fds = fds;
+ memset(fds + epollop->nfds, 0,
+ (nfds - epollop->nfds) * sizeof(struct evepoll));
+ epollop->nfds = nfds;
+ }
+
+ return (evsignal_recalc(&epollop->evsigmask));
+}
+
+int
+epoll_dispatch(struct event_base *base, void *arg, struct timeval *tv)
+{
+ struct epollop *epollop = arg;
+ struct epoll_event *events = epollop->events;
+ struct evepoll *evep;
+ int i, res, timeout;
+
+ if (evsignal_deliver(&epollop->evsigmask) == -1)
+ return (-1);
+
+ timeout = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000;
+ res = epoll_wait(epollop->epfd, events, epollop->nevents, timeout);
+
+ if (evsignal_recalc(&epollop->evsigmask) == -1)
+ return (-1);
+
+ if (res == -1) {
+ if (errno != EINTR) {
+ event_warn("epoll_wait");
+ return (-1);
+ }
+
+ evsignal_process();
+ return (0);
+ } else if (evsignal_caught)
+ evsignal_process();
+
+ event_debug(("%s: epoll_wait reports %d", __func__, res));
+
+ for (i = 0; i < res; i++) {
+ int which = 0;
+ int what = events[i].events;
+ struct event *evread = NULL, *evwrite = NULL;
+
+ evep = (struct evepoll *)events[i].data.ptr;
+
+ if (what & EPOLLHUP)
+ what |= EPOLLIN | EPOLLOUT;
+ else if (what & EPOLLERR)
+ what |= EPOLLIN | EPOLLOUT;
+
+ if (what & EPOLLIN) {
+ evread = evep->evread;
+ which |= EV_READ;
+ }
+
+ if (what & EPOLLOUT) {
+ evwrite = evep->evwrite;
+ which |= EV_WRITE;
+ }
+
+ if (!which)
+ continue;
+
+ if (evread != NULL && !(evread->ev_events & EV_PERSIST))
+ event_del(evread);
+ if (evwrite != NULL && evwrite != evread &&
+ !(evwrite->ev_events & EV_PERSIST))
+ event_del(evwrite);
+
+ if (evread != NULL)
+ event_active(evread, EV_READ, 1);
+ if (evwrite != NULL)
+ event_active(evwrite, EV_WRITE, 1);
+ }
+
+ return (0);
+}
+
+
+int
+epoll_add(void *arg, struct event *ev)
+{
+ struct epollop *epollop = arg;
+ struct epoll_event epev = {0, {0}};
+ struct evepoll *evep;
+ int fd, op, events;
+
+ if (ev->ev_events & EV_SIGNAL)
+ return (evsignal_add(&epollop->evsigmask, ev));
+
+ fd = ev->ev_fd;
+ if (fd >= epollop->nfds) {
+ /* Extent the file descriptor array as necessary */
+ if (epoll_recalc(ev->ev_base, epollop, fd) == -1)
+ return (-1);
+ }
+ evep = &epollop->fds[fd];
+ op = EPOLL_CTL_ADD;
+ events = 0;
+ if (evep->evread != NULL) {
+ events |= EPOLLIN;
+ op = EPOLL_CTL_MOD;
+ }
+ if (evep->evwrite != NULL) {
+ events |= EPOLLOUT;
+ op = EPOLL_CTL_MOD;
+ }
+
+ if (ev->ev_events & EV_READ)
+ events |= EPOLLIN;
+ if (ev->ev_events & EV_WRITE)
+ events |= EPOLLOUT;
+
+ epev.data.ptr = evep;
+ epev.events = events;
+ if (epoll_ctl(epollop->epfd, op, ev->ev_fd, &epev) == -1)
+ return (-1);
+
+ /* Update events responsible */
+ if (ev->ev_events & EV_READ)
+ evep->evread = ev;
+ if (ev->ev_events & EV_WRITE)
+ evep->evwrite = ev;
+
+ return (0);
+}
+
+int
+epoll_del(void *arg, struct event *ev)
+{
+ struct epollop *epollop = arg;
+ struct epoll_event epev = {0, {0}};
+ struct evepoll *evep;
+ int fd, events, op;
+ int needwritedelete = 1, needreaddelete = 1;
+
+ if (ev->ev_events & EV_SIGNAL)
+ return (evsignal_del(&epollop->evsigmask, ev));
+
+ fd = ev->ev_fd;
+ if (fd >= epollop->nfds)
+ return (0);
+ evep = &epollop->fds[fd];
+
+ op = EPOLL_CTL_DEL;
+ events = 0;
+
+ if (ev->ev_events & EV_READ)
+ events |= EPOLLIN;
+ if (ev->ev_events & EV_WRITE)
+ events |= EPOLLOUT;
+
+ if ((events & (EPOLLIN|EPOLLOUT)) != (EPOLLIN|EPOLLOUT)) {
+ if ((events & EPOLLIN) && evep->evwrite != NULL) {
+ needwritedelete = 0;
+ events = EPOLLOUT;
+ op = EPOLL_CTL_MOD;
+ } else if ((events & EPOLLOUT) && evep->evread != NULL) {
+ needreaddelete = 0;
+ events = EPOLLIN;
+ op = EPOLL_CTL_MOD;
+ }
+ }
+
+ epev.events = events;
+ epev.data.ptr = evep;
+
+ if (needreaddelete)
+ evep->evread = NULL;
+ if (needwritedelete)
+ evep->evwrite = NULL;
+
+ if (epoll_ctl(epollop->epfd, op, fd, &epev) == -1)
+ return (-1);
+
+ return (0);
+}
+
+void
+epoll_dealloc(void *arg)
+{
+ struct epollop *epollop = arg;
+
+ if (epollop->fds)
+ free(epollop->fds);
+ if (epollop->events)
+ free(epollop->events);
+ if (epollop->epfd >= 0)
+ close(epollop->epfd);
+
+ memset(epollop, 0, sizeof(struct epollop));
+ free(epollop);
+}
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