2 * IRC - Internet Relay Chat, ircd/engine_kqueue.c
3 * Copyright (C) 2001 Kevin L. Mitchell <klmitch@mit.edu>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 1, or (at your option)
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 * @brief FreeBSD kqueue()/kevent() event engine.
25 #include "ircd_events.h"
28 #include "ircd_alloc.h"
29 #include "ircd_features.h"
33 /* #include <assert.h> -- Now using assert in ircd_log.h */
36 #include <sys/types.h>
37 #include <sys/event.h>
38 #include <sys/socket.h>
43 #define KQUEUE_ERROR_THRESHOLD 20 /**< after 20 kqueue errors, restart */
44 #define ERROR_EXPIRE_TIME 3600 /**< expire errors after an hour */
46 /** Array of active Socket structures, indexed by file descriptor. */
47 static struct Socket** sockList;
48 /** Maximum file descriptor supported, plus one. */
49 static int kqueue_max;
50 /** File descriptor for kqueue pseudo-file. */
52 /** Current array of event descriptors. */
53 static struct kevent *events;
54 /** Number of ::events elements that have been populated. */
55 static int events_used;
56 /** Current processing position in ::events. */
59 /** Number of recent errors from kqueue. */
60 static int errors = 0;
61 /** Periodic timer to forget errors. */
62 static struct Timer clear_error;
64 /** Decrement the error count (once per hour).
65 * @param[in] ev Expired timer event (ignored).
68 error_clear(struct Event* ev)
70 if (!--errors) /* remove timer when error count reaches 0 */
71 timer_del(ev_timer(ev));
74 /** Initialize the kqueue engine.
75 * @param[in] max_sockets Maximum number of file descriptors to support.
76 * @return Non-zero on success, or zero on failure.
79 engine_init(int max_sockets)
83 if ((kqueue_id = kqueue()) < 0) { /* initialize... */
84 log_write(LS_SYSTEM, L_WARNING, 0,
85 "kqueue() engine cannot initialize: %m");
89 /* allocate necessary memory */
90 sockList = (struct Socket**) MyMalloc(sizeof(struct Socket*) * max_sockets);
92 /* initialize the data */
93 for (i = 0; i < max_sockets; i++)
96 kqueue_max = max_sockets; /* number of sockets allocated */
98 return 1; /* success! */
101 /** Add a signal to the event engine.
102 * @param[in] sig Signal to add to engine.
105 engine_signal(struct Signal* sig)
107 struct kevent sigevent;
108 struct sigaction act;
112 Debug((DEBUG_ENGINE, "kqueue: Adding filter for signal %d [%p]",
113 sig_signal(sig), sig));
115 sigevent.ident = sig_signal(sig); /* set up the kqueue event */
116 sigevent.filter = EVFILT_SIGNAL; /* looking for signals... */
117 sigevent.flags = EV_ADD | EV_ENABLE; /* add and enable it */
120 sigevent.udata = sig; /* store our user data */
122 if (kevent(kqueue_id, &sigevent, 1, 0, 0, 0) < 0) { /* add event */
123 log_write(LS_SYSTEM, L_WARNING, 0, "Unable to trap signal %d",
128 act.sa_handler = SIG_IGN; /* ignore the signal */
130 sigemptyset(&act.sa_mask);
131 sigaction(sig_signal(sig), &act, 0);
134 /** Figure out what events go with a given state.
135 * @param[in] state %Socket state to consider.
136 * @param[in] events User-specified preferred event set.
137 * @return Actual set of preferred events.
140 state_to_events(enum SocketState state, unsigned int events)
143 case SS_CONNECTING: /* connecting socket */
144 return SOCK_EVENT_WRITABLE;
147 case SS_LISTENING: /* listening socket */
148 case SS_NOTSOCK: /* our signal socket--just in case */
149 return SOCK_EVENT_READABLE;
152 case SS_CONNECTED: case SS_DATAGRAM: case SS_CONNECTDG:
153 return events; /* ordinary socket */
161 /** Activate kqueue filters as appropriate.
162 * @param[in] sock Socket structure to operate on.
163 * @param[in] clear Set of interest events to clear from socket.
164 * @param[in] set Set of interest events to set on socket.
167 set_or_clear(struct Socket* sock, unsigned int clear, unsigned int set)
170 struct kevent chglist[2];
173 assert(-1 < s_fd(sock));
175 if ((clear ^ set) & SOCK_EVENT_READABLE) { /* readable has changed */
176 chglist[i].ident = s_fd(sock); /* set up the change list */
177 chglist[i].filter = EVFILT_READ; /* readable filter */
178 chglist[i].flags = EV_ADD; /* adding it */
179 chglist[i].fflags = 0;
181 chglist[i].udata = 0; /* I love udata, but it can't really be used here */
183 if (set & SOCK_EVENT_READABLE) /* it's set */
184 chglist[i].flags |= EV_ENABLE;
186 chglist[i].flags |= EV_DISABLE;
188 i++; /* advance to next element */
191 if ((clear ^ set) & SOCK_EVENT_WRITABLE) { /* writable has changed */
192 chglist[i].ident = s_fd(sock); /* set up the change list */
193 chglist[i].filter = EVFILT_WRITE; /* writable filter */
194 chglist[i].flags = EV_ADD; /* adding it */
195 chglist[i].fflags = 0;
197 chglist[i].udata = 0;
199 if (set & SOCK_EVENT_WRITABLE) /* it's set */
200 chglist[i].flags |= EV_ENABLE;
202 chglist[i].flags |= EV_DISABLE;
204 i++; /* advance count... */
207 if (kevent(kqueue_id, chglist, i, 0, 0, 0) < 0 && errno != EBADF)
208 event_generate(ET_ERROR, sock, errno); /* report error */
211 /** Add a socket to the event engine.
212 * @param[in] sock Socket to add to engine.
213 * @return Non-zero on success, or zero on error.
216 engine_add(struct Socket* sock)
219 assert(0 == sockList[s_fd(sock)]);
221 /* bounds-check... */
222 if (sock->s_fd >= kqueue_max) {
223 log_write(LS_SYSTEM, L_ERROR, 0,
224 "Attempt to add socket %d (> %d) to event engine", s_fd(sock),
229 sockList[s_fd(sock)] = sock; /* add to list */
231 Debug((DEBUG_ENGINE, "kqueue: Adding socket %d [%p], state %s, to engine",
232 s_fd(sock), sock, state_to_name(s_state(sock))));
234 /* Add socket to queue */
235 set_or_clear(sock, 0, state_to_events(s_state(sock), s_events(sock)));
237 return 1; /* success */
240 /** Handle state transition for a socket.
241 * @param[in] sock Socket changing state.
242 * @param[in] new_state New state for socket.
245 engine_state(struct Socket* sock, enum SocketState new_state)
248 assert(sock == sockList[s_fd(sock)]);
250 Debug((DEBUG_ENGINE, "kqueue: Changing state for socket %p to %s", sock,
251 state_to_name(new_state)));
253 /* set the correct events */
255 state_to_events(s_state(sock), s_events(sock)), /* old state */
256 state_to_events(new_state, s_events(sock))); /* new state */
260 /** Handle change to preferred socket events.
261 * @param[in] sock Socket getting new interest list.
262 * @param[in] new_events New set of interesting events for socket.
265 engine_events(struct Socket* sock, unsigned int new_events)
268 assert(sock == sockList[s_fd(sock)]);
270 Debug((DEBUG_ENGINE, "kqueue: Changing event mask for socket %p to [%s]",
271 sock, sock_flags(new_events)));
273 /* set the correct events */
275 state_to_events(s_state(sock), s_events(sock)), /* old events */
276 state_to_events(s_state(sock), new_events)); /* new events */
279 /** Remove a socket from the event engine.
280 * @param[in] sock Socket being destroyed.
283 engine_delete(struct Socket* sock)
288 assert(sock == sockList[s_fd(sock)]);
290 Debug((DEBUG_ENGINE, "kqueue: Deleting socket %d [%p], state %s",
291 s_fd(sock), sock, state_to_name(s_state(sock))));
293 sockList[s_fd(sock)] = 0;
295 /* Drop any unprocessed events citing this socket. */
296 for (ii = events_i; ii < events_used; ii++) {
297 if (events[ii].ident == s_fd(sock)) {
298 events[ii] = events[--events_used];
303 /** Run engine event loop.
304 * @param[in] gen Lists of generators of various types.
307 engine_loop(struct Generators* gen)
312 struct timespec wait;
317 if ((events_count = feature_int(FEAT_POLLS_PER_LOOP)) < 20)
319 events = (struct kevent *)MyMalloc(sizeof(struct kevent) * events_count);
322 if ((i = feature_int(FEAT_POLLS_PER_LOOP)) >= 20 && i != events_count) {
323 events = (struct kevent *)MyRealloc(events, sizeof(struct kevent) * i);
327 /* set up the sleep time */
328 wait.tv_sec = timer_next(gen) ? (timer_next(gen) - CurrentTime) : -1;
331 Debug((DEBUG_ENGINE, "kqueue: delay: %Tu (%Tu) %Tu", timer_next(gen),
332 CurrentTime, wait.tv_sec));
334 /* check for active events */
335 events_used = kevent(kqueue_id, 0, 0, events, events_count,
336 wait.tv_sec < 0 ? 0 : &wait);
338 CurrentTime = time(0); /* set current time... */
340 if (events_used < 0) {
341 if (errno != EINTR) { /* ignore kevent interrupts */
342 /* Log the kqueue error */
343 log_write(LS_SOCKET, L_ERROR, 0, "kevent() error: %m");
345 timer_add(timer_init(&clear_error), error_clear, 0, TT_PERIODIC,
347 else if (errors > KQUEUE_ERROR_THRESHOLD) /* too many errors... */
348 server_restart("too many kevent errors");
350 /* old code did a sleep(1) here; with usage these days,
351 * that may be too expensive
356 for (events_i = 0; events_i < events_used; events_i++) {
357 evt = &events[events_i];
359 if (evt->filter == EVFILT_SIGNAL) {
360 /* it's a signal; deal appropriately */
361 event_generate(ET_SIGNAL, evt->udata, evt->ident);
362 continue; /* skip socket processing loop */
365 assert(evt->filter == EVFILT_READ || evt->filter == EVFILT_WRITE);
367 sock = sockList[evt->ident];
368 if (!sock) /* slots may become empty while processing events */
371 assert(s_fd(sock) == evt->ident);
373 gen_ref_inc(sock); /* can't have it going away on us */
375 Debug((DEBUG_ENGINE, "kqueue: Checking socket %p (fd %d) state %s, "
376 "events %s", sock, s_fd(sock), state_to_name(s_state(sock)),
377 sock_flags(s_events(sock))));
379 if (s_state(sock) != SS_NOTSOCK) {
380 errcode = 0; /* check for errors on socket */
381 codesize = sizeof(errcode);
382 if (getsockopt(s_fd(sock), SOL_SOCKET, SO_ERROR, &errcode,
384 errcode = errno; /* work around Solaris implementation */
386 if (errcode) { /* an error occurred; generate an event */
387 Debug((DEBUG_ENGINE, "kqueue: Error %d on fd %d, socket %p", errcode,
389 event_generate(ET_ERROR, sock, errcode);
390 gen_ref_dec(sock); /* careful not to leak reference counts */
395 switch (s_state(sock)) {
397 if (evt->filter == EVFILT_WRITE) { /* connection completed */
398 Debug((DEBUG_ENGINE, "kqueue: Connection completed"));
399 event_generate(ET_CONNECT, sock, 0);
404 if (evt->filter == EVFILT_READ) { /* connect. to be accept. */
405 Debug((DEBUG_ENGINE, "kqueue: Ready for accept"));
406 event_generate(ET_ACCEPT, sock, 0);
410 case SS_NOTSOCK: /* doing nothing socket-specific */
412 if (evt->filter == EVFILT_READ) { /* data on socket */
413 Debug((DEBUG_ENGINE, "kqueue: EOF or data to be read"));
414 event_generate(evt->flags & EV_EOF ? ET_EOF : ET_READ, sock, 0);
416 if (evt->filter == EVFILT_WRITE) { /* socket writable */
417 Debug((DEBUG_ENGINE, "kqueue: Data can be written"));
418 event_generate(ET_WRITE, sock, 0);
422 case SS_DATAGRAM: case SS_CONNECTDG:
423 if (evt->filter == EVFILT_READ) { /* socket readable */
424 Debug((DEBUG_ENGINE, "kqueue: Datagram to be read"));
425 event_generate(ET_READ, sock, 0);
427 if (evt->filter == EVFILT_WRITE) { /* socket writable */
428 Debug((DEBUG_ENGINE, "kqueue: Datagram can be written"));
429 event_generate(ET_WRITE, sock, 0);
434 gen_ref_dec(sock); /* we're done with it */
437 timer_run(); /* execute any pending timers */
441 /** Descriptor for kqueue() event engine. */
442 struct Engine engine_kqueue = {
443 "kqueue()", /* Engine name */
444 engine_init, /* Engine initialization function */
445 engine_signal, /* Engine signal registration function */
446 engine_add, /* Engine socket registration function */
447 engine_state, /* Engine socket state change function */
448 engine_events, /* Engine socket events mask function */
449 engine_delete, /* Engine socket deletion function */
450 engine_loop /* Core engine event loop */