1 files changed, 373 insertions, 0 deletions
diff --git a/libevent/epoll.c b/libevent/epoll.c
new file mode 100644
index 00000000000..b479b9c07e9
--- /dev/null
+++ b/libevent/epoll.c
@@ -0,0 +1,373 @@
+/*
+ * 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 "event-internal.h"
+#include "evsignal.h"
+#include "log.h"
+
+/* 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;
+};
+
+static void *epoll_init	(struct event_base *);
+static int epoll_add	(void *, struct event *);
+static int epoll_del	(void *, struct event *);
+static int epoll_dispatch	(struct event_base *, void *, struct timeval *);
+static void epoll_dealloc	(struct event_base *, void *);
+
+const struct eventop epollops = {
+	"epoll",
+	epoll_init,
+	epoll_add,
+	epoll_del,
+	epoll_dispatch,
+	epoll_dealloc,
+	1 /* need reinit */
+};
+
+#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
+
+/* On Linux kernels at least up to 2.6.24.4, epoll can't handle timeout
+ * values bigger than (LONG_MAX - 999ULL)/HZ.  HZ in the wild can be
+ * as big as 1000, and LONG_MAX can be as small as (1<<31)-1, so the
+ * largest number of msec we can support here is 2147482.  Let's
+ * round that down by 47 seconds.
+ */
+#define MAX_EPOLL_TIMEOUT_MSEC (35*60*1000)
+
+static void *
+epoll_init(struct event_base *base)
+{
+	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) {
+		if (errno != ENOSYS)
+			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(base);
+
+	return (epollop);
+}
+
+static 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 (0);
+}
+
+static 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 = -1;
+
+	if (tv != NULL)
+		timeout = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000;
+
+	if (timeout > MAX_EPOLL_TIMEOUT_MSEC) {
+		/* Linux kernels can wait forever if the timeout is too big;
+		 * see comment on MAX_EPOLL_TIMEOUT_MSEC. */
+		timeout = MAX_EPOLL_TIMEOUT_MSEC;
+	}
+
+	res = epoll_wait(epollop->epfd, events, epollop->nevents, timeout);
+
+	if (res == -1) {
+		if (errno != EINTR) {
+			event_warn("epoll_wait");
+			return (-1);
+		}
+
+		evsignal_process(base);
+		return (0);
+	} else if (base->sig.evsignal_caught) {
+		evsignal_process(base);
+	}
+
+	event_debug(("%s: epoll_wait reports %d", __func__, res));
+
+	for (i = 0; i < res; i++) {
+		int what = events[i].events;
+		struct event *evread = NULL, *evwrite = NULL;
+		int fd = events[i].data.fd;
+
+		if (fd < 0 || fd >= epollop->nfds)
+			continue;
+		evep = &epollop->fds[fd];
+
+		if (what & (EPOLLHUP|EPOLLERR)) {
+			evread = evep->evread;
+			evwrite = evep->evwrite;
+		} else {
+			if (what & EPOLLIN) {
+				evread = evep->evread;
+			}
+
+			if (what & EPOLLOUT) {
+				evwrite = evep->evwrite;
+			}
+		}
+
+		if (!(evread||evwrite))
+			continue;
+
+		if (evread != NULL)
+			event_active(evread, EV_READ, 1);
+		if (evwrite != NULL)
+			event_active(evwrite, EV_WRITE, 1);
+	}
+
+	return (0);
+}
+
+
+static 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(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.fd = fd;
+	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);
+}
+
+static 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(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.fd = fd;
+
+	if (needreaddelete)
+		evep->evread = NULL;
+	if (needwritedelete)
+		evep->evwrite = NULL;
+
+	if (epoll_ctl(epollop->epfd, op, fd, &epev) == -1)
+		return (-1);
+
+	return (0);
+}
+
+static void
+epoll_dealloc(struct event_base *base, void *arg)
+{
+	struct epollop *epollop = arg;
+
+	evsignal_dealloc(base);
+	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);
+}