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/*
* Copyright 2000-2009 Niels Provos <provos@citi.umich.edu>
* Copyright 2009-2012 Niels Provos and Nick Mathewson
*
* 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.
*/
#include "event2/event-config.h"
#include "evconfig-private.h"
#ifdef EVENT__HAVE_DEVPOLL
#include <sys/types.h>
#include <sys/resource.h>
#ifdef EVENT__HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <sys/queue.h>
#include <sys/devpoll.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include "event2/event.h"
#include "event2/event_struct.h"
#include "event2/thread.h"
#include "event-internal.h"
#include "evsignal-internal.h"
#include "log-internal.h"
#include "evmap-internal.h"
#include "evthread-internal.h"
struct devpollop {
struct pollfd *events;
int nevents;
int dpfd;
struct pollfd *changes;
int nchanges;
};
static void *devpoll_init(struct event_base *);
static int devpoll_add(struct event_base *, int fd, short old, short events, void *);
static int devpoll_del(struct event_base *, int fd, short old, short events, void *);
static int devpoll_dispatch(struct event_base *, struct timeval *);
static void devpoll_dealloc(struct event_base *);
const struct eventop devpollops = {
"devpoll",
devpoll_init,
devpoll_add,
devpoll_del,
devpoll_dispatch,
devpoll_dealloc,
1, /* need reinit */
EV_FEATURE_FDS|EV_FEATURE_O1,
0
};
#define NEVENT 32000
static int
devpoll_commit(struct devpollop *devpollop)
{
/*
* Due to a bug in Solaris, we have to use pwrite with an offset of 0.
* Write is limited to 2GB of data, until it will fail.
*/
if (pwrite(devpollop->dpfd, devpollop->changes,
sizeof(struct pollfd) * devpollop->nchanges, 0) == -1)
return (-1);
devpollop->nchanges = 0;
return (0);
}
static int
devpoll_queue(struct devpollop *devpollop, int fd, int events) {
struct pollfd *pfd;
if (devpollop->nchanges >= devpollop->nevents) {
/*
* Change buffer is full, must commit it to /dev/poll before
* adding more
*/
if (devpoll_commit(devpollop) != 0)
return (-1);
}
pfd = &devpollop->changes[devpollop->nchanges++];
pfd->fd = fd;
pfd->events = events;
pfd->revents = 0;
return (0);
}
static void *
devpoll_init(struct event_base *base)
{
int dpfd, nfiles = NEVENT;
struct rlimit rl;
struct devpollop *devpollop;
if (!(devpollop = mm_calloc(1, sizeof(struct devpollop))))
return (NULL);
if (getrlimit(RLIMIT_NOFILE, &rl) == 0 &&
rl.rlim_cur != RLIM_INFINITY)
nfiles = rl.rlim_cur;
/* Initialize the kernel queue */
if ((dpfd = evutil_open_closeonexec_("/dev/poll", O_RDWR, 0)) == -1) {
event_warn("open: /dev/poll");
mm_free(devpollop);
return (NULL);
}
devpollop->dpfd = dpfd;
/* Initialize fields */
/* FIXME: allocating 'nfiles' worth of space here can be
* expensive and unnecessary. See how epoll.c does it instead. */
devpollop->events = mm_calloc(nfiles, sizeof(struct pollfd));
if (devpollop->events == NULL) {
mm_free(devpollop);
close(dpfd);
return (NULL);
}
devpollop->nevents = nfiles;
devpollop->changes = mm_calloc(nfiles, sizeof(struct pollfd));
if (devpollop->changes == NULL) {
mm_free(devpollop->events);
mm_free(devpollop);
close(dpfd);
return (NULL);
}
evsig_init_(base);
return (devpollop);
}
static int
devpoll_dispatch(struct event_base *base, struct timeval *tv)
{
struct devpollop *devpollop = base->evbase;
struct pollfd *events = devpollop->events;
struct dvpoll dvp;
int i, res, timeout = -1;
if (devpollop->nchanges)
devpoll_commit(devpollop);
if (tv != NULL)
timeout = tv->tv_sec * 1000 + (tv->tv_usec + 999) / 1000;
dvp.dp_fds = devpollop->events;
dvp.dp_nfds = devpollop->nevents;
dvp.dp_timeout = timeout;
EVBASE_RELEASE_LOCK(base, th_base_lock);
res = ioctl(devpollop->dpfd, DP_POLL, &dvp);
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
if (res == -1) {
if (errno != EINTR) {
event_warn("ioctl: DP_POLL");
return (-1);
}
return (0);
}
event_debug(("%s: devpoll_wait reports %d", __func__, res));
for (i = 0; i < res; i++) {
int which = 0;
int what = events[i].revents;
if (what & POLLHUP)
what |= POLLIN | POLLOUT;
else if (what & POLLERR)
what |= POLLIN | POLLOUT;
if (what & POLLIN)
which |= EV_READ;
if (what & POLLOUT)
which |= EV_WRITE;
if (!which)
continue;
/* XXX(niels): not sure if this works for devpoll */
evmap_io_active_(base, events[i].fd, which);
}
return (0);
}
static int
devpoll_add(struct event_base *base, int fd, short old, short events, void *p)
{
struct devpollop *devpollop = base->evbase;
int res;
(void)p;
/*
* It's not necessary to OR the existing read/write events that we
* are currently interested in with the new event we are adding.
* The /dev/poll driver ORs any new events with the existing events
* that it has cached for the fd.
*/
res = 0;
if (events & EV_READ)
res |= POLLIN;
if (events & EV_WRITE)
res |= POLLOUT;
if (devpoll_queue(devpollop, fd, res) != 0)
return (-1);
return (0);
}
static int
devpoll_del(struct event_base *base, int fd, short old, short events, void *p)
{
struct devpollop *devpollop = base->evbase;
int res;
(void)p;
res = 0;
if (events & EV_READ)
res |= POLLIN;
if (events & EV_WRITE)
res |= POLLOUT;
/*
* The only way to remove an fd from the /dev/poll monitored set is
* to use POLLREMOVE by itself. This removes ALL events for the fd
* provided so if we care about two events and are only removing one
* we must re-add the other event after POLLREMOVE.
*/
if (devpoll_queue(devpollop, fd, POLLREMOVE) != 0)
return (-1);
if ((res & (POLLIN|POLLOUT)) != (POLLIN|POLLOUT)) {
/*
* We're not deleting all events, so we must resubmit the
* event that we are still interested in if one exists.
*/
if ((res & POLLIN) && (old & EV_WRITE)) {
/* Deleting read, still care about write */
devpoll_queue(devpollop, fd, POLLOUT);
} else if ((res & POLLOUT) && (old & EV_READ)) {
/* Deleting write, still care about read */
devpoll_queue(devpollop, fd, POLLIN);
}
}
return (0);
}
static void
devpoll_dealloc(struct event_base *base)
{
struct devpollop *devpollop = base->evbase;
evsig_dealloc_(base);
if (devpollop->events)
mm_free(devpollop->events);
if (devpollop->changes)
mm_free(devpollop->changes);
if (devpollop->dpfd >= 0)
close(devpollop->dpfd);
memset(devpollop, 0, sizeof(struct devpollop));
mm_free(devpollop);
}
#endif /* EVENT__HAVE_DEVPOLL */