1 /* $OpenBSD: kqueue.c,v 1.5 2002/07/10 14:41:31 art Exp $ */
4 * Copyright 2000-2002 Niels Provos <provos@citi.umich.edu>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 #include <sys/types.h>
34 #ifdef HAVE_SYS_TIME_H
37 #include <sys/_time.h>
39 #include <sys/queue.h>
40 #include <sys/event.h>
47 #ifdef HAVE_INTTYPES_H
51 /* Some platforms apparently define the udata field of struct kevent as
52 * ntptr_t, whereas others define it as void*. There doesn't seem to be an
53 * easy way to tell them apart via autoconf, so we need to use OS macros. */
54 #define PTR_TO_UDATA(x) ((void *)(x))
59 #define EVLIST_X_KQINKERNEL 0x1000
64 struct kevent *changes;
66 struct kevent *events;
71 void *kq_init (struct event_base *);
72 int kq_add (void *, struct event *);
73 int kq_del (void *, struct event *);
74 int kq_recalc (struct event_base *, void *, int);
75 int kq_dispatch (struct event_base *, void *, struct timeval *);
76 int kq_insert (struct kqop *, struct kevent *);
77 void kq_dealloc (struct event_base *, void *);
79 const struct eventop kqops = {
90 kq_init(struct event_base *base)
93 struct kqop *kqueueop;
95 /* Disable kqueue when this environment variable is set */
96 if (getenv("EVENT_NOKQUEUE"))
99 if (!(kqueueop = calloc(1, sizeof(struct kqop))))
102 /* Initalize the kernel queue */
104 if ((kq = kqueue()) == -1) {
105 event_warn("kqueue");
112 /* Initalize fields */
113 kqueueop->changes = malloc(NEVENT * sizeof(struct kevent));
114 if (kqueueop->changes == NULL) {
118 kqueueop->events = malloc(NEVENT * sizeof(struct kevent));
119 if (kqueueop->events == NULL) {
120 free (kqueueop->changes);
124 kqueueop->nevents = NEVENT;
126 /* Check for Mac OS X kqueue bug. */
127 kqueueop->changes[0].ident = -1;
128 kqueueop->changes[0].filter = EVFILT_READ;
129 kqueueop->changes[0].flags = EV_ADD;
131 * If kqueue works, then kevent will succeed, and it will
132 * stick an error in events[0]. If kqueue is broken, then
136 kqueueop->changes, 1, kqueueop->events, NEVENT, NULL) != 1 ||
137 kqueueop->events[0].ident != -1 ||
138 kqueueop->events[0].flags != EV_ERROR) {
139 event_warn("%s: detected broken kqueue; not using.", __func__);
140 free(kqueueop->changes);
141 free(kqueueop->events);
151 kq_recalc(struct event_base *base, void *arg, int max)
157 kq_insert(struct kqop *kqop, struct kevent *kev)
159 int nevents = kqop->nevents;
161 if (kqop->nchanges == nevents) {
162 struct kevent *newchange;
163 struct kevent *newresult;
167 newchange = realloc(kqop->changes,
168 nevents * sizeof(struct kevent));
169 if (newchange == NULL) {
170 event_warn("%s: malloc", __func__);
173 kqop->changes = newchange;
175 newresult = realloc(kqop->events,
176 nevents * sizeof(struct kevent));
179 * If we fail, we don't have to worry about freeing,
180 * the next realloc will pick it up.
182 if (newresult == NULL) {
183 event_warn("%s: malloc", __func__);
186 kqop->events = newresult;
188 kqop->nevents = nevents;
191 memcpy(&kqop->changes[kqop->nchanges++], kev, sizeof(struct kevent));
193 event_debug(("%s: fd %d %s%s",
194 __func__, kev->ident,
195 kev->filter == EVFILT_READ ? "EVFILT_READ" : "EVFILT_WRITE",
196 kev->flags == EV_DELETE ? " (del)" : ""));
202 kq_sighandler(int sig)
204 /* Do nothing here */
208 kq_dispatch(struct event_base *base, void *arg, struct timeval *tv)
210 struct kqop *kqop = arg;
211 struct kevent *changes = kqop->changes;
212 struct kevent *events = kqop->events;
214 struct timespec ts, *ts_p = NULL;
218 TIMEVAL_TO_TIMESPEC(tv, &ts);
222 res = kevent(kqop->kq, changes, kqop->nchanges,
223 events, kqop->nevents, ts_p);
226 if (errno != EINTR) {
227 event_warn("kevent");
234 event_debug(("%s: kevent reports %d", __func__, res));
236 for (i = 0; i < res; i++) {
239 if (events[i].flags & EV_ERROR) {
241 * Error messages that can happen, when a delete fails.
242 * EBADF happens when the file discriptor has been
244 * ENOENT when the file discriptor was closed and
246 * EINVAL for some reasons not understood; EINVAL
247 * should not be returned ever; but FreeBSD does :-\
248 * An error is also indicated when a callback deletes
249 * an event we are still processing. In that case
250 * the data field is set to ENOENT.
252 if (events[i].data == EBADF ||
253 events[i].data == EINVAL ||
254 events[i].data == ENOENT)
256 errno = events[i].data;
260 ev = (struct event *)events[i].udata;
262 if (events[i].filter == EVFILT_READ) {
264 } else if (events[i].filter == EVFILT_WRITE) {
266 } else if (events[i].filter == EVFILT_SIGNAL) {
273 if (!(ev->ev_events & EV_PERSIST))
276 event_active(ev, which,
277 ev->ev_events & EV_SIGNAL ? events[i].data : 1);
285 kq_add(void *arg, struct event *ev)
287 struct kqop *kqop = arg;
290 if (ev->ev_events & EV_SIGNAL) {
291 int nsignal = EVENT_SIGNAL(ev);
293 memset(&kev, 0, sizeof(kev));
295 kev.filter = EVFILT_SIGNAL;
297 if (!(ev->ev_events & EV_PERSIST))
298 kev.flags |= EV_ONESHOT;
299 kev.udata = PTR_TO_UDATA(ev);
301 if (kq_insert(kqop, &kev) == -1)
304 if (signal(nsignal, kq_sighandler) == SIG_ERR)
307 ev->ev_flags |= EVLIST_X_KQINKERNEL;
311 if (ev->ev_events & EV_READ) {
312 memset(&kev, 0, sizeof(kev));
313 kev.ident = ev->ev_fd;
314 kev.filter = EVFILT_READ;
316 /* Make it behave like select() and poll() */
317 kev.fflags = NOTE_EOF;
320 if (!(ev->ev_events & EV_PERSIST))
321 kev.flags |= EV_ONESHOT;
322 kev.udata = PTR_TO_UDATA(ev);
324 if (kq_insert(kqop, &kev) == -1)
327 ev->ev_flags |= EVLIST_X_KQINKERNEL;
330 if (ev->ev_events & EV_WRITE) {
331 memset(&kev, 0, sizeof(kev));
332 kev.ident = ev->ev_fd;
333 kev.filter = EVFILT_WRITE;
335 if (!(ev->ev_events & EV_PERSIST))
336 kev.flags |= EV_ONESHOT;
337 kev.udata = PTR_TO_UDATA(ev);
339 if (kq_insert(kqop, &kev) == -1)
342 ev->ev_flags |= EVLIST_X_KQINKERNEL;
349 kq_del(void *arg, struct event *ev)
351 struct kqop *kqop = arg;
354 if (!(ev->ev_flags & EVLIST_X_KQINKERNEL))
357 if (ev->ev_events & EV_SIGNAL) {
358 int nsignal = EVENT_SIGNAL(ev);
360 memset(&kev, 0, sizeof(kev));
362 kev.filter = EVFILT_SIGNAL;
363 kev.flags = EV_DELETE;
365 if (kq_insert(kqop, &kev) == -1)
368 if (signal(nsignal, SIG_DFL) == SIG_ERR)
371 ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
375 if (ev->ev_events & EV_READ) {
376 memset(&kev, 0, sizeof(kev));
377 kev.ident = ev->ev_fd;
378 kev.filter = EVFILT_READ;
379 kev.flags = EV_DELETE;
381 if (kq_insert(kqop, &kev) == -1)
384 ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
387 if (ev->ev_events & EV_WRITE) {
388 memset(&kev, 0, sizeof(kev));
389 kev.ident = ev->ev_fd;
390 kev.filter = EVFILT_WRITE;
391 kev.flags = EV_DELETE;
393 if (kq_insert(kqop, &kev) == -1)
396 ev->ev_flags &= ~EVLIST_X_KQINKERNEL;
403 kq_dealloc(struct event_base *base, void *arg)
405 struct kqop *kqop = arg;
413 memset(kqop, 0, sizeof(struct kqop));