Repo created

TMessagesProj/jni/voip/webrtc/base/third_party/libevent/kqueue.c

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+/*	$OpenBSD: kqueue.c,v 1.5 2002/07/10 14:41:31 art Exp $	*/
+
+/*
+ * Copyright 2000-2002 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.
+ */
+
+#include "config.h"
+
+#define _GNU_SOURCE 1
+
+#include <sys/types.h>
+#ifdef HAVE_SYS_TIME_H
+#include <sys/time.h>
+#else
+#include <sys/_libevent_time.h>
+#endif
+#include <sys/queue.h>
+#include <sys/event.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <assert.h>
+#ifdef HAVE_INTTYPES_H
+#include <inttypes.h>
+#endif
+
+/* Some platforms apparently define the udata field of struct kevent as
+ * intptr_t, whereas others define it as void*.  There doesn't seem to be an
+ * easy way to tell them apart via autoconf, so we need to use OS macros. */
+#if defined(HAVE_INTTYPES_H) && !defined(__OpenBSD__) && !defined(__FreeBSD__) && !defined(__darwin__) && !defined(__APPLE__)
+#define PTR_TO_UDATA(x)	((intptr_t)(x))
+#else
+#define PTR_TO_UDATA(x)	(x)
+#endif
+
+#include "event.h"
+#include "event-internal.h"
+#include "log.h"
+#include "evsignal.h"
+
+#define EVLIST_X_KQINKERNEL	0x1000
+
+#define NEVENT		64
+
+struct kqop {
+	struct kevent *changes;
+	int nchanges;
+	struct kevent *events;
+	struct event_list evsigevents[NSIG];
+	int nevents;
+	int kq;
+	pid_t pid;
+};
+
+static void *kq_init	(struct event_base *);
+static int kq_add	(void *, struct event *);
+static int kq_del	(void *, struct event *);
+static int kq_dispatch	(struct event_base *, void *, struct timeval *);
+static int kq_insert	(struct kqop *, struct kevent *);
+static void kq_dealloc (struct event_base *, void *);
+
+const struct eventop kqops = {
+	"kqueue",
+	kq_init,
+	kq_add,
+	kq_del,
+	kq_dispatch,
+	kq_dealloc,
+	1 /* need reinit */
+};
+
+static void *
+kq_init(struct event_base *base)
+{
+	int i, kq;
+	struct kqop *kqueueop;
+
+	/* Disable kqueue when this environment variable is set */
+	if (evutil_getenv("EVENT_NOKQUEUE"))
+		return (NULL);
+
+	if (!(kqueueop = calloc(1, sizeof(struct kqop))))
+		return (NULL);
+
+	/* Initalize the kernel queue */
+	
+	if ((kq = kqueue()) == -1) {
+		event_warn("kqueue");
+		free (kqueueop);
+		return (NULL);
+	}
+
+	kqueueop->kq = kq;
+
+	kqueueop->pid = getpid();
+
+	/* Initalize fields */
+	kqueueop->changes = malloc(NEVENT * sizeof(struct kevent));
+	if (kqueueop->changes == NULL) {
+		free (kqueueop);
+		return (NULL);
+	}
+	kqueueop->events = malloc(NEVENT * sizeof(struct kevent));
+	if (kqueueop->events == NULL) {
+		free (kqueueop->changes);
+		free (kqueueop);
+		return (NULL);
+	}
+	kqueueop->nevents = NEVENT;
+
+	/* we need to keep track of multiple events per signal */
+	for (i = 0; i < NSIG; ++i) {
+		TAILQ_INIT(&kqueueop->evsigevents[i]);
+	}
+
+	return (kqueueop);
+}
+
+static int
+kq_insert(struct kqop *kqop, struct kevent *kev)
+{
+	int nevents = kqop->nevents;
+
+	if (kqop->nchanges == nevents) {
+		struct kevent *newchange;
+		struct kevent *newresult;
+
+		nevents *= 2;
+
+		newchange = realloc(kqop->changes,
+				    nevents * sizeof(struct kevent));
+		if (newchange == NULL) {
+			event_warn("%s: malloc", __func__);
+			return (-1);
+		}
+		kqop->changes = newchange;
+
+		newresult = realloc(kqop->events,
+				    nevents * sizeof(struct kevent));
+
+		/*
+		 * If we fail, we don't have to worry about freeing,
+		 * the next realloc will pick it up.
+		 */
+		if (newresult == NULL) {
+			event_warn("%s: malloc", __func__);
+			return (-1);
+		}
+		kqop->events = newresult;
+
+		kqop->nevents = nevents;
+	}
+
+	memcpy(&kqop->changes[kqop->nchanges++], kev, sizeof(struct kevent));
+
+	event_debug(("%s: fd %d %s%s",
+		__func__, (int)kev->ident, 
+		kev->filter == EVFILT_READ ? "EVFILT_READ" : "EVFILT_WRITE",
+		kev->flags == EV_DELETE ? " (del)" : ""));
+
+	return (0);
+}
+
+static void
+kq_sighandler(int sig)
+{
+	/* Do nothing here */
+}
+
+static int
+kq_dispatch(struct event_base *base, void *arg, struct timeval *tv)
+{
+	struct kqop *kqop = arg;
+	struct kevent *changes = kqop->changes;
+	struct kevent *events = kqop->events;
+	struct event *ev;
+	struct timespec ts, *ts_p = NULL;
+	int i, res;
+
+	if (tv != NULL) {
+		TIMEVAL_TO_TIMESPEC(tv, &ts);
+		ts_p = &ts;
+	}
+
+	res = kevent(kqop->kq, changes, kqop->nchanges,
+	    events, kqop->nevents, ts_p);
+	kqop->nchanges = 0;
+	if (res == -1) {
+		if (errno != EINTR) {
+                        event_warn("kevent");
+			return (-1);
+		}
+
+		return (0);
+	}
+
+	event_debug(("%s: kevent reports %d", __func__, res));
+
+	for (i = 0; i < res; i++) {
+		int which = 0;
+
+		if (events[i].flags & EV_ERROR) {
+			/* 
+			 * Error messages that can happen, when a delete fails.
+			 *   EBADF happens when the file discriptor has been
+			 *   closed,
+			 *   ENOENT when the file discriptor was closed and
+			 *   then reopened.
+			 *   EINVAL for some reasons not understood; EINVAL
+			 *   should not be returned ever; but FreeBSD does :-\
+			 * An error is also indicated when a callback deletes
+			 * an event we are still processing.  In that case
+			 * the data field is set to ENOENT.
+			 */
+			if (events[i].data == EBADF ||
+			    events[i].data == EINVAL ||
+			    events[i].data == ENOENT)
+				continue;
+			errno = events[i].data;
+			return (-1);
+		}
+
+		if (events[i].filter == EVFILT_READ) {
+			which |= EV_READ;
+		} else if (events[i].filter == EVFILT_WRITE) {
+			which |= EV_WRITE;
+		} else if (events[i].filter == EVFILT_SIGNAL) {
+			which |= EV_SIGNAL;
+		}
+
+		if (!which)
+			continue;
+
+		if (events[i].filter == EVFILT_SIGNAL) {
+			struct event_list *head =
+			    (struct event_list *)events[i].udata;
+			TAILQ_FOREACH(ev, head, ev_signal_next) {
+				event_active(ev, which, events[i].data);
+			}
+		} else {
+			ev = (struct event *)events[i].udata;
+
+			if (!(ev->ev_events & EV_PERSIST))
+				ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
+
+			event_active(ev, which, 1);
+		}
+	}
+
+	return (0);
+}
+
+
+static int
+kq_add(void *arg, struct event *ev)
+{
+	struct kqop *kqop = arg;
+	struct kevent kev;
+
+	if (ev->ev_events & EV_SIGNAL) {
+		int nsignal = EVENT_SIGNAL(ev);
+
+		assert(nsignal >= 0 && nsignal < NSIG);
+		if (TAILQ_EMPTY(&kqop->evsigevents[nsignal])) {
+			struct timespec timeout = { 0, 0 };
+			
+			memset(&kev, 0, sizeof(kev));
+			kev.ident = nsignal;
+			kev.filter = EVFILT_SIGNAL;
+			kev.flags = EV_ADD;
+			kev.udata = PTR_TO_UDATA(&kqop->evsigevents[nsignal]);
+			
+			/* Be ready for the signal if it is sent any
+			 * time between now and the next call to
+			 * kq_dispatch. */
+			if (kevent(kqop->kq, &kev, 1, NULL, 0, &timeout) == -1)
+				return (-1);
+			
+			if (_evsignal_set_handler(ev->ev_base, nsignal,
+				kq_sighandler) == -1)
+				return (-1);
+		}
+
+		TAILQ_INSERT_TAIL(&kqop->evsigevents[nsignal], ev,
+		    ev_signal_next);
+		ev->ev_flags |= EVLIST_X_KQINKERNEL;
+		return (0);
+	}
+
+	if (ev->ev_events & EV_READ) {
+ 		memset(&kev, 0, sizeof(kev));
+		kev.ident = ev->ev_fd;
+		kev.filter = EVFILT_READ;
+#ifdef NOTE_EOF
+		/* Make it behave like select() and poll() */
+		kev.fflags = NOTE_EOF;
+#endif
+		kev.flags = EV_ADD;
+		if (!(ev->ev_events & EV_PERSIST))
+			kev.flags |= EV_ONESHOT;
+		kev.udata = PTR_TO_UDATA(ev);
+		
+		if (kq_insert(kqop, &kev) == -1)
+			return (-1);
+
+		ev->ev_flags |= EVLIST_X_KQINKERNEL;
+	}
+
+	if (ev->ev_events & EV_WRITE) {
+ 		memset(&kev, 0, sizeof(kev));
+		kev.ident = ev->ev_fd;
+		kev.filter = EVFILT_WRITE;
+		kev.flags = EV_ADD;
+		if (!(ev->ev_events & EV_PERSIST))
+			kev.flags |= EV_ONESHOT;
+		kev.udata = PTR_TO_UDATA(ev);
+		
+		if (kq_insert(kqop, &kev) == -1)
+			return (-1);
+
+		ev->ev_flags |= EVLIST_X_KQINKERNEL;
+	}
+
+	return (0);
+}
+
+static int
+kq_del(void *arg, struct event *ev)
+{
+	struct kqop *kqop = arg;
+	struct kevent kev;
+
+	if (!(ev->ev_flags & EVLIST_X_KQINKERNEL))
+		return (0);
+
+	if (ev->ev_events & EV_SIGNAL) {
+		int nsignal = EVENT_SIGNAL(ev);
+		struct timespec timeout = { 0, 0 };
+
+		assert(nsignal >= 0 && nsignal < NSIG);
+		TAILQ_REMOVE(&kqop->evsigevents[nsignal], ev, ev_signal_next);
+		if (TAILQ_EMPTY(&kqop->evsigevents[nsignal])) {
+			memset(&kev, 0, sizeof(kev));
+			kev.ident = nsignal;
+			kev.filter = EVFILT_SIGNAL;
+			kev.flags = EV_DELETE;
+		
+			/* Because we insert signal events
+			 * immediately, we need to delete them
+			 * immediately, too */
+			if (kevent(kqop->kq, &kev, 1, NULL, 0, &timeout) == -1)
+				return (-1);
+
+			if (_evsignal_restore_handler(ev->ev_base,
+				nsignal) == -1)
+				return (-1);
+		}
+
+		ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
+		return (0);
+	}
+
+	if (ev->ev_events & EV_READ) {
+ 		memset(&kev, 0, sizeof(kev));
+		kev.ident = ev->ev_fd;
+		kev.filter = EVFILT_READ;
+		kev.flags = EV_DELETE;
+		
+		if (kq_insert(kqop, &kev) == -1)
+			return (-1);
+
+		ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
+	}
+
+	if (ev->ev_events & EV_WRITE) {
+ 		memset(&kev, 0, sizeof(kev));
+		kev.ident = ev->ev_fd;
+		kev.filter = EVFILT_WRITE;
+		kev.flags = EV_DELETE;
+		
+		if (kq_insert(kqop, &kev) == -1)
+			return (-1);
+
+		ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
+	}
+
+	return (0);
+}
+
+static void
+kq_dealloc(struct event_base *base, void *arg)
+{
+	struct kqop *kqop = arg;
+
+	evsignal_dealloc(base);
+
+	if (kqop->changes)
+		free(kqop->changes);
+	if (kqop->events)
+		free(kqop->events);
+	if (kqop->kq >= 0 && kqop->pid == getpid())
+		close(kqop->kq);
+
+	memset(kqop, 0, sizeof(struct kqop));
+	free(kqop);
+}