Squashed 'third_party/libevent/' content from commit d8ceae8
Change-Id: I84e1b23561eb225b9f288717b028e6bc9e5a27e1
git-subtree-dir: third_party/libevent
git-subtree-split: d8ceae81b83f3d0a56e2f41d4c429b2702a8e302
diff --git a/devpoll.c b/devpoll.c
new file mode 100644
index 0000000..f99cc01
--- /dev/null
+++ b/devpoll.c
@@ -0,0 +1,306 @@
+/*
+ * 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 <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);
+}