2 * IRC - Internet Relay Chat, ircd/ircd_events.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.
23 #include "ircd_events.h"
26 #include "ircd_alloc.h"
28 #include "ircd_snprintf.h"
36 #define SIGS_PER_SOCK 10 /* number of signals to process per socket
40 extern struct Engine engine_kqueue;
41 #define ENGINE_KQUEUE &engine_kqueue,
44 #endif /* USE_KQUEUE */
47 extern struct Engine engine_devpoll;
48 #define ENGINE_DEVPOLL &engine_devpoll,
50 #define ENGINE_DEVPOLL
51 #endif /* USE_DEVPOLL */
54 extern struct Engine engine_poll;
55 #define ENGINE_FALLBACK &engine_poll,
57 extern struct Engine engine_select;
58 #define ENGINE_FALLBACK &engine_select,
61 /* list of engines to try */
62 static const struct Engine *evEngines[] = {
69 /* signal routines pipe data */
71 int fd; /* signal routine's fd */
72 struct Socket sock; /* and its struct Socket */
75 /* All the thread info */
77 struct Generators gens; /* List of all generators */
78 struct Event* events_free; /* struct Event free list */
79 unsigned int events_alloc; /* count of allocated struct Events */
80 const struct Engine* engine; /* core engine being used */
82 struct GenHeader* genq_head; /* head of generator event queue */
83 struct GenHeader* genq_tail; /* tail of generator event queue */
84 unsigned int genq_count; /* count of generators on queue */
94 /* Initialize a struct GenHeader */
96 gen_init(struct GenHeader* gen, EventCallBack call, void* data,
97 struct GenHeader* next, struct GenHeader** prev_p)
102 gen->gh_prev_p = prev_p;
109 gen->gh_flags = GEN_ACTIVE;
113 gen->gh_engdata.ed_int = 0;
115 if (prev_p) { /* Going to link into list? */
116 if (next) /* do so */
117 next->gh_prev_p = &gen->gh_next;
122 /* Execute an event; optimizations should inline this */
124 event_execute(struct Event* event)
127 assert(0 == event->ev_prev_p); /* must be off queue first */
128 assert(event->ev_gen.gen_header->gh_flags & GEN_ACTIVE);
130 if (event->ev_type == ET_DESTROY) /* turn off active flag *before* destroy */
131 event->ev_gen.gen_header->gh_flags &= ~GEN_ACTIVE;
132 if (event->ev_type == ET_ERROR) /* turn on error flag before callback */
133 event->ev_gen.gen_header->gh_flags |= GEN_ERROR;
135 (*event->ev_gen.gen_header->gh_call)(event); /* execute the event */
137 /* The logic here is very careful; if the event was an ET_DESTROY,
138 * then we must assume the generator is now invalid; fortunately, we
139 * don't need to do anything to it if so. Otherwise, we decrement
140 * the reference count; if reference count goes to zero, AND we need
141 * to destroy the generator, THEN we generate a DESTROY event.
143 if (event->ev_type != ET_DESTROY)
144 gen_ref_dec(event->ev_gen.gen_header);
146 event->ev_gen.gen_header = 0; /* clear event data */
147 event->ev_type = ET_DESTROY;
149 event->ev_next = evInfo.events_free; /* add to free list */
150 evInfo.events_free = event;
153 #ifndef IRCD_THREADED
154 /* we synchronously execute the event when not threaded */
155 #define event_add(event) \
157 struct Event* _ev = (event); \
159 _ev->ev_prev_p = 0; \
160 event_execute(_ev); \
164 /* add an event to the work queue */
165 /* This is just a placeholder; don't expect ircd to be threaded soon */
166 /* There should be locks all over the place in here */
168 event_add(struct Event* event)
170 struct GenHeader* gen;
174 gen = event->ev_gen.gen_header;
176 /* First, place event on generator's event queue */
179 assert(0 != gen->gh_tail);
181 event->ev_prev_p = &gen->gh_tail->ev_next;
182 gen->gh_tail->ev_next = event;
183 gen->gh_tail = event;
184 } else { /* queue was empty */
185 assert(0 == gen->gh_tail);
187 event->ev_prev_p = &gen->gh_head;
188 gen->gh_head = event;
189 gen->gh_tail = event;
192 /* Now, if the generator isn't on the queue yet... */
193 if (!gen->gh_qprev_p) {
195 if (evInfo.genq_head) {
196 assert(0 != evInfo.genq_tail);
198 gen->gh_qprev_p = &evInfo.genq_tail->gh_qnext;
199 evInfo.genq_tail->gh_qnext = gen;
200 evInfo.genq_tail = gen;
201 } else { /* queue was empty */
202 assert(0 == evInfo.genq_tail);
204 gen->gh_qprev_p = &evInfo.genq_head;
205 evInfo.genq_head = gen;
206 evInfo.genq_tail = gen;
209 /* We'd also have to signal the work crew here */
212 #endif /* IRCD_THREADED */
214 /* Place a timer in the correct spot on the queue */
216 timer_enqueue(struct Timer* timer)
218 struct Timer** ptr_p;
221 assert(0 == timer->t_header.gh_prev_p); /* not already on queue */
222 assert(timer->t_header.gh_flags & GEN_ACTIVE); /* timer is active */
224 /* Calculate expire time */
225 switch (timer->t_type) {
226 case TT_ABSOLUTE: /* no need to consider it relative */
227 timer->t_expire = timer->t_value;
230 case TT_RELATIVE: case TT_PERIODIC: /* relative timer */
231 timer->t_expire = timer->t_value + CurrentTime;
235 /* Find a slot to insert timer */
236 for (ptr_p = &evInfo.gens.g_timer; ;
237 ptr_p = (struct Timer**) &(*ptr_p)->t_header.gh_next)
238 if (!*ptr_p || timer->t_expire < (*ptr_p)->t_expire)
241 /* link it in the right place */
242 timer->t_header.gh_next = (struct GenHeader*) *ptr_p;
243 timer->t_header.gh_prev_p = (struct GenHeader**) ptr_p;
245 (*ptr_p)->t_header.gh_prev_p = &timer->t_header.gh_next;
249 /* signal handler for writing signal notification to pipe */
251 signal_handler(int sig)
255 assert(sigInfo.fd >= 0);
257 c = (unsigned char) sig; /* only write 1 byte to identify sig */
259 write(sigInfo.fd, &c, 1);
262 /* callback for signal "socket" events */
264 signal_callback(struct Event* event)
266 unsigned char sigstr[SIGS_PER_SOCK];
270 assert(event->ev_type == ET_READ); /* readable events only */
272 n_sigs = read(event->ev_gen.gen_socket->s_fd, sigstr, sizeof(sigstr));
274 for (i = 0; i < n_sigs; i++) {
275 sig = (int) sigstr[i]; /* get signal */
277 for (ptr = evInfo.gens.g_signal; ptr;
278 ptr = (struct Signal*) ptr->sig_header.gh_next)
279 if (ptr->sig_signal == sig) /* find its descriptor... */
283 event_generate(ET_SIGNAL, ptr, sig); /* generate signal event */
287 /* Remove something from its queue */
289 gen_dequeue(void* arg)
291 struct GenHeader* gen = (struct GenHeader*) arg;
293 if (gen->gh_next) /* clip it out of the list */
294 gen->gh_next->gh_prev_p = gen->gh_prev_p;
296 *gen->gh_prev_p = gen->gh_next;
298 gen->gh_next = 0; /* mark that it's not in the list anymore */
302 /* Initializes the event system */
304 event_init(int max_sockets)
308 for (i = 0; evEngines[i]; i++) { /* look for an engine... */
309 assert(0 != evEngines[i]->eng_name);
310 assert(0 != evEngines[i]->eng_init);
312 if ((*evEngines[i]->eng_init)(max_sockets))
313 break; /* Found an engine that'll work */
316 assert(0 != evEngines[i]);
318 evInfo.engine = evEngines[i]; /* save engine */
320 if (!evInfo.engine->eng_signal) { /* engine can't do signals */
322 log_write(LS_SYSTEM, L_CRIT, 0, "Failed to open signal pipe");
326 sigInfo.fd = p[1]; /* write end of pipe */
327 socket_add(&sigInfo.sock, signal_callback, 0, SS_NOTSOCK,
328 SOCK_EVENT_READABLE, p[0]); /* read end of pipe */
332 /* Do the event loop */
336 assert(0 != evInfo.engine);
337 assert(0 != evInfo.engine->eng_loop);
339 (*evInfo.engine->eng_loop)(&evInfo.gens);
342 /* Generate an event and add it to the queue (or execute it) */
344 event_generate(enum EventType type, void* arg, int data)
347 struct GenHeader* gen = (struct GenHeader*) arg;
351 /* don't create events (other than ET_DESTROY) for destroyed generators */
352 if (type != ET_DESTROY && (gen->gh_flags & GEN_DESTROY))
355 Debug((DEBUG_LIST, "Generating event type %s for generator %p (%s)",
356 event_to_name(type), gen, gen_flags(gen->gh_flags)));
358 if ((ptr = evInfo.events_free))
359 evInfo.events_free = ptr->ev_next; /* pop one off the freelist */
360 else { /* allocate another structure */
361 ptr = (struct Event*) MyMalloc(sizeof(struct Event));
362 evInfo.events_alloc++; /* count of allocated events */
365 ptr->ev_type = type; /* Record event type */
368 ptr->ev_gen.gen_header = (struct GenHeader*) gen;
369 ptr->ev_gen.gen_header->gh_ref++;
371 event_add(ptr); /* add event to queue */
375 /* Try to verify the timer list */
380 struct Timer** ptr_p = &evInfo.gens.g_timer;
383 for (ptr = evInfo.gens.g_timer; ptr;
384 ptr = (struct Timer*) ptr->t_header.gh_next) {
385 /* verify timer is supposed to be in the list */
386 assert(ptr->t_header.gh_prev_p);
387 /* verify timer is correctly ordered */
388 assert((struct Timer**) ptr->t_header.gh_prev_p == ptr_p);
389 /* verify timer is active */
390 assert(ptr->t_header.gh_flags & GEN_ACTIVE);
391 /* verify timer ordering is correct */
392 assert(lasttime <= ptr->t_expire);
394 lasttime = ptr->t_expire; /* store time for ordering check */
395 ptr_p = (struct Timer**) &ptr->t_header.gh_next; /* store prev pointer */
400 /* Initialize a timer structure */
402 timer_init(struct Timer* timer)
404 gen_init((struct GenHeader*) timer, 0, 0, 0, 0);
406 timer->t_header.gh_flags = 0; /* turn off active flag */
408 return timer; /* convenience return */
411 /* Add a timer to be processed */
413 timer_add(struct Timer* timer, EventCallBack call, void* data,
414 enum TimerType type, time_t value)
419 Debug((DEBUG_LIST, "Adding timer %p; time out %Tu (type %s)", timer, value,
420 timer_to_name(type)));
422 /* initialize a timer... */
423 timer->t_header.gh_flags |= GEN_ACTIVE;
424 if (timer->t_header.gh_flags & GEN_MARKED)
425 timer->t_header.gh_flags |= GEN_READD;
427 timer->t_header.gh_ref = 0;
428 timer->t_header.gh_call = call;
429 timer->t_header.gh_data = data;
431 timer->t_type = type;
432 timer->t_value = value;
435 if (!(timer->t_header.gh_flags & GEN_MARKED))
436 timer_enqueue(timer); /* and enqueue it */
439 /* Remove a timer from the processing queue */
441 timer_del(struct Timer* timer)
445 timer->t_header.gh_flags &= ~GEN_READD;
447 if (timer->t_header.gh_flags & GEN_MARKED)
448 return; /* timer is being used */
450 Debug((DEBUG_LIST, "Deleting timer %p (type %s)", timer,
451 timer_to_name(timer->t_type)));
454 event_generate(ET_DESTROY, timer, 0);
457 /* Change the time a timer expires */
459 timer_chg(struct Timer* timer, enum TimerType type, time_t value)
463 assert(TT_PERIODIC != timer->t_type);
464 assert(TT_PERIODIC != type);
466 Debug((DEBUG_LIST, "Changing timer %p from type %s timeout %Tu to type %s "
467 "timeout %Tu", timer, timer_to_name(timer->t_type), timer->t_value,
468 timer_to_name(type), value));
470 gen_dequeue(timer); /* remove the timer from the queue */
472 timer->t_type = type; /* Set the new type and value */
473 timer->t_value = value;
476 timer_enqueue(timer); /* re-queue the timer */
479 /* Execute all expired timers */
485 /* go through queue... */
486 while ((ptr = evInfo.gens.g_timer)) {
487 if (CurrentTime < ptr->t_expire)
488 break; /* processed all pending timers */
490 gen_dequeue(ptr); /* must dequeue timer here */
491 ptr->t_header.gh_flags |= (GEN_MARKED |
492 (ptr->t_type == TT_PERIODIC ? GEN_READD : 0));
494 event_generate(ET_EXPIRE, ptr, 0); /* generate expire event */
496 ptr->t_header.gh_flags &= ~GEN_MARKED;
498 if (!(ptr->t_header.gh_flags & GEN_READD)) {
499 Debug((DEBUG_LIST, "Destroying timer %p", ptr));
500 event_generate(ET_DESTROY, ptr, 0);
502 Debug((DEBUG_LIST, "Re-enqueuing timer %p", ptr));
503 timer_enqueue(ptr); /* re-queue timer */
504 ptr->t_header.gh_flags &= ~GEN_READD;
509 /* Adds a signal to the event callback system */
511 signal_add(struct Signal* signal, EventCallBack call, void* data, int sig)
513 struct sigaction act;
517 assert(0 != evInfo.engine);
520 gen_init((struct GenHeader*) signal, call, data,
521 (struct GenHeader*) evInfo.gens.g_signal,
522 (struct GenHeader**) &evInfo.gens.g_signal);
524 signal->sig_signal = sig;
526 if (evInfo.engine->eng_signal)
527 (*evInfo.engine->eng_signal)(signal); /* tell engine */
529 act.sa_handler = signal_handler; /* set up signal handler */
531 sigemptyset(&act.sa_mask);
532 sigaction(sig, &act, 0);
536 /* Adds a socket to the event system */
538 socket_add(struct Socket* sock, EventCallBack call, void* data,
539 enum SocketState state, unsigned int events, int fd)
544 assert(0 != evInfo.engine);
545 assert(0 != evInfo.engine->eng_add);
548 gen_init((struct GenHeader*) sock, call, data,
549 (struct GenHeader*) evInfo.gens.g_socket,
550 (struct GenHeader**) &evInfo.gens.g_socket);
552 sock->s_state = state;
553 sock->s_events = events & SOCK_EVENT_MASK;
556 return (*evInfo.engine->eng_add)(sock); /* tell engine about it */
559 /* deletes (or marks for deletion) a socket */
561 socket_del(struct Socket* sock)
564 assert(!(sock->s_header.gh_flags & GEN_DESTROY));
565 assert(0 != evInfo.engine);
566 assert(0 != evInfo.engine->eng_closing);
568 /* tell engine socket is going away */
569 (*evInfo.engine->eng_closing)(sock);
571 sock->s_header.gh_flags |= GEN_DESTROY;
573 if (!sock->s_header.gh_ref) { /* not in use; destroy right now */
575 event_generate(ET_DESTROY, sock, 0);
579 /* Sets the socket state to something else */
581 socket_state(struct Socket* sock, enum SocketState state)
584 assert(0 != evInfo.engine);
585 assert(0 != evInfo.engine->eng_state);
587 /* assertions for invalid socket state transitions */
588 assert(sock->s_state != state); /* not changing states ?! */
589 assert(sock->s_state != SS_LISTENING); /* listening socket to...?! */
590 assert(sock->s_state != SS_CONNECTED); /* connected socket to...?! */
591 /* connecting socket now connected */
592 assert(sock->s_state != SS_CONNECTING || state == SS_CONNECTED);
593 /* unconnected datagram socket now connected */
594 assert(sock->s_state != SS_DATAGRAM || state == SS_CONNECTDG);
595 /* connected datagram socket now unconnected */
596 assert(sock->s_state != SS_CONNECTDG || state == SS_DATAGRAM);
598 /* Don't continue if an error occurred or the socket got destroyed */
599 if (sock->s_header.gh_flags & (GEN_DESTROY | GEN_ERROR))
602 /* tell engine we're changing socket state */
603 (*evInfo.engine->eng_state)(sock, state);
605 sock->s_state = state; /* set new state */
608 /* sets the events a socket's interested in */
610 socket_events(struct Socket* sock, unsigned int events)
612 unsigned int new_events = 0;
615 assert(0 != evInfo.engine);
616 assert(0 != evInfo.engine->eng_events);
618 /* Don't continue if an error occurred or the socket got destroyed */
619 if (sock->s_header.gh_flags & (GEN_DESTROY | GEN_ERROR))
622 switch (events & SOCK_ACTION_MASK) {
623 case SOCK_ACTION_SET: /* set events to given set */
624 new_events = events & SOCK_EVENT_MASK;
627 case SOCK_ACTION_ADD: /* add some events */
628 new_events = sock->s_events | (events & SOCK_EVENT_MASK);
631 case SOCK_ACTION_DEL: /* remove some events */
632 new_events = sock->s_events & ~(events & SOCK_EVENT_MASK);
636 if (sock->s_events == new_events)
637 return; /* no changes have been made */
639 /* tell engine about event mask change */
640 (*evInfo.engine->eng_events)(sock, new_events);
642 sock->s_events = new_events; /* set new events */
645 /* Returns an engine's name for informational purposes */
649 assert(0 != evInfo.engine);
650 assert(0 != evInfo.engine->eng_name);
652 return evInfo.engine->eng_name;
656 /* These routines pretty-print names for states and types for debug printing */
664 #define NM(name) { #name, name }
669 state_to_name(enum SocketState state)
672 NS(enum SocketState) map[] = {
682 for (i = 0; map[i].name; i++)
683 if (map[i].value == state)
686 return "Undefined socket state";
690 timer_to_name(enum TimerType type)
693 NS(enum TimerType) map[] = {
700 for (i = 0; map[i].name; i++)
701 if (map[i].value == type)
704 return "Undefined timer type";
708 event_to_name(enum EventType type)
711 NS(enum EventType) map[] = {
724 for (i = 0; map[i].name; i++)
725 if (map[i].value == type)
728 return "Undefined event type";
732 gen_flags(unsigned int flags)
735 static char buf[256];
736 NS(unsigned int) map[] = {
747 for (i = 0; map[i].name; i++)
748 if (map[i].value & flags) {
751 loc += ircd_snprintf(0, buf + loc, sizeof(buf) - loc, "%s", map[i].name);
752 if (loc >= sizeof(buf))
753 return buf; /* overflow case */
760 sock_flags(unsigned int flags)
763 static char buf[256];
764 NS(unsigned int) map[] = {
765 NM(SOCK_EVENT_READABLE),
766 NM(SOCK_EVENT_WRITABLE),
775 for (i = 0; map[i].name; i++)
776 if (map[i].value & flags) {
779 loc += ircd_snprintf(0, buf + loc, sizeof(buf) - loc, "%s", map[i].name);
780 if (loc >= sizeof(buf))
781 return buf; /* overflow case */
787 #endif /* DEBUGMODE */