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"
35 #define SIGS_PER_SOCK 10 /* number of signals to process per socket
39 extern struct Engine engine_kqueue;
40 #define ENGINE_KQUEUE &engine_kqueue,
43 #endif /* USE_KQUEUE */
46 extern struct Engine engine_devpoll;
47 #define ENGINE_DEVPOLL &engine_devpoll,
49 #define ENGINE_DEVPOLL
50 #endif /* USE_DEVPOLL */
53 extern struct Engine engine_poll;
54 #define ENGINE_FALLBACK &engine_poll,
56 extern struct Engine engine_select;
57 #define ENGINE_FALLBACK &engine_select,
60 /* list of engines to try */
61 static const struct Engine *evEngines[] = {
68 /* signal routines pipe data */
70 int fd; /* signal routine's fd */
71 struct Socket sock; /* and its struct Socket */
74 /* All the thread info */
76 struct Generators gens; /* List of all generators */
77 struct Event* events_free; /* struct Event free list */
78 unsigned int events_alloc; /* count of allocated struct Events */
79 const struct Engine* engine; /* core engine being used */
81 struct GenHeader* genq_head; /* head of generator event queue */
82 struct GenHeader* genq_tail; /* tail of generator event queue */
83 unsigned int genq_count; /* count of generators on queue */
93 /* Initialize a struct GenHeader */
95 gen_init(struct GenHeader* gen, EventCallBack call, void* data,
96 struct GenHeader* next, struct GenHeader** prev_p)
101 gen->gh_prev_p = prev_p;
108 gen->gh_flags = GEN_ACTIVE;
112 gen->gh_engdata.ed_int = 0;
114 if (prev_p) { /* Going to link into list? */
115 if (next) /* do so */
116 next->gh_prev_p = &gen->gh_next;
121 /* Execute an event; optimizations should inline this */
123 event_execute(struct Event* event)
126 assert(0 == event->ev_prev_p); /* must be off queue first */
127 assert(event->ev_gen.gen_header->gh_flags & GEN_ACTIVE);
129 if (event->ev_type == ET_DESTROY) /* turn off active flag *before* destroy */
130 event->ev_gen.gen_header->gh_flags &= ~GEN_ACTIVE;
132 (*event->ev_gen.gen_header->gh_call)(event); /* execute the event */
134 /* The logic here is very careful; if the event was an ET_DESTROY,
135 * then we must assume the generator is now invalid; fortunately, we
136 * don't need to do anything to it if so. Otherwise, we decrement
137 * the reference count; if reference count goes to zero, AND we need
138 * to destroy the generator, THEN we generate a DESTROY event.
140 if (event->ev_type != ET_DESTROY)
141 gen_ref_dec(event->ev_gen.gen_header);
143 event->ev_gen.gen_header = 0; /* clear event data */
144 event->ev_type = ET_DESTROY;
146 event->ev_next = evInfo.events_free; /* add to free list */
147 evInfo.events_free = event;
150 #ifndef IRCD_THREADED
151 /* we synchronously execute the event when not threaded */
152 #define event_add(event) \
154 struct Event* _ev = (event); \
156 _ev->ev_prev_p = 0; \
157 event_execute(_ev); \
161 /* add an event to the work queue */
162 /* This is just a placeholder; don't expect ircd to be threaded soon */
163 /* There should be locks all over the place in here */
165 event_add(struct Event* event)
167 struct GenHeader* gen;
171 gen = event->ev_gen.gen_header;
173 /* First, place event on generator's event queue */
176 assert(0 != gen->gh_tail);
178 event->ev_prev_p = &gen->gh_tail->ev_next;
179 gen->gh_tail->ev_next = event;
180 gen->gh_tail = event;
181 } else { /* queue was empty */
182 assert(0 == gen->gh_tail);
184 event->ev_prev_p = &gen->gh_head;
185 gen->gh_head = event;
186 gen->gh_tail = event;
189 /* Now, if the generator isn't on the queue yet... */
190 if (!gen->gh_qprev_p) {
192 if (evInfo.genq_head) {
193 assert(0 != evInfo.genq_tail);
195 gen->gh_qprev_p = &evInfo.genq_tail->gh_qnext;
196 evInfo.genq_tail->gh_qnext = gen;
197 evInfo.genq_tail = gen;
198 } else { /* queue was empty */
199 assert(0 == evInfo.genq_tail);
201 gen->gh_qprev_p = &evInfo.genq_head;
202 evInfo.genq_head = gen;
203 evInfo.genq_tail = gen;
206 /* We'd also have to signal the work crew here */
209 #endif /* IRCD_THREADED */
211 /* Place a timer in the correct spot on the queue */
213 timer_enqueue(struct Timer* timer)
215 struct Timer** ptr_p;
218 assert(0 == timer->t_header.gh_prev_p); /* not already on queue */
220 /* Calculate expire time */
221 switch (timer->t_type) {
222 case TT_ABSOLUTE: /* no need to consider it relative */
223 timer->t_expire = timer->t_value;
226 case TT_RELATIVE: case TT_PERIODIC: /* relative timer */
227 timer->t_expire = timer->t_value + CurrentTime;
231 /* Find a slot to insert timer */
232 for (ptr_p = &evInfo.gens.g_timer; ;
233 ptr_p = (struct Timer**) &(*ptr_p)->t_header.gh_next)
234 if (!*ptr_p || timer->t_expire < (*ptr_p)->t_expire)
237 /* link it in the right place */
238 timer->t_header.gh_next = (struct GenHeader*) *ptr_p;
239 timer->t_header.gh_prev_p = (struct GenHeader**) ptr_p;
241 (*ptr_p)->t_header.gh_prev_p = &timer->t_header.gh_next;
245 /* signal handler for writing signal notification to pipe */
247 signal_handler(int sig)
251 assert(sigInfo.fd >= 0);
253 c = (unsigned char) sig; /* only write 1 byte to identify sig */
255 write(sigInfo.fd, &c, 1);
258 /* callback for signal "socket" events */
260 signal_callback(struct Event* event)
262 unsigned char sigstr[SIGS_PER_SOCK];
266 assert(event->ev_type == ET_READ); /* readable events only */
268 n_sigs = read(event->ev_gen.gen_socket->s_fd, sigstr, sizeof(sigstr));
270 for (i = 0; i < n_sigs; i++) {
271 sig = (int) sigstr[i]; /* get signal */
273 for (ptr = evInfo.gens.g_signal; ptr;
274 ptr = (struct Signal*) ptr->sig_header.gh_next)
275 if (ptr->sig_signal == sig) /* find its descriptor... */
279 event_generate(ET_SIGNAL, ptr, sig); /* generate signal event */
283 /* Remove something from its queue */
285 gen_dequeue(void* arg)
287 struct GenHeader* gen = (struct GenHeader*) arg;
289 if (gen->gh_next) /* clip it out of the list */
290 gen->gh_next->gh_prev_p = gen->gh_prev_p;
292 *gen->gh_prev_p = gen->gh_next;
294 gen->gh_next = 0; /* mark that it's not in the list anymore */
298 /* Initializes the event system */
300 event_init(int max_sockets)
304 for (i = 0; evEngines[i]; i++) { /* look for an engine... */
305 assert(0 != evEngines[i]->eng_name);
306 assert(0 != evEngines[i]->eng_init);
308 if ((*evEngines[i]->eng_init)(max_sockets))
309 break; /* Found an engine that'll work */
312 assert(0 != evEngines[i]);
314 evInfo.engine = evEngines[i]; /* save engine */
316 if (!evInfo.engine->eng_signal) { /* engine can't do signals */
318 log_write(LS_SYSTEM, L_CRIT, 0, "Failed to open signal pipe");
322 sigInfo.fd = p[1]; /* write end of pipe */
323 socket_add(&sigInfo.sock, signal_callback, 0, SS_NOTSOCK,
324 SOCK_EVENT_READABLE, p[0]); /* read end of pipe */
328 /* Do the event loop */
332 assert(0 != evInfo.engine);
333 assert(0 != evInfo.engine->eng_loop);
335 (*evInfo.engine->eng_loop)(&evInfo.gens);
338 /* Generate an event and add it to the queue (or execute it) */
340 event_generate(enum EventType type, void* arg, int data)
343 struct GenHeader* gen = (struct GenHeader*) arg;
347 /* don't create events (other than ET_DESTROY) for destroyed generators */
348 if (type != ET_DESTROY && (gen->gh_flags & GEN_DESTROY))
351 Debug((DEBUG_LIST, "Generating event type %s for generator %p (%s)",
352 event_to_name(type), gen, gen_flags(gen->gh_flags)));
354 if ((ptr = evInfo.events_free))
355 evInfo.events_free = ptr->ev_next; /* pop one off the freelist */
356 else { /* allocate another structure */
357 ptr = (struct Event*) MyMalloc(sizeof(struct Event));
358 evInfo.events_alloc++; /* count of allocated events */
361 ptr->ev_type = type; /* Record event type */
364 ptr->ev_gen.gen_header = (struct GenHeader*) gen;
365 ptr->ev_gen.gen_header->gh_ref++;
367 event_add(ptr); /* add event to queue */
370 /* Add a timer to be processed */
372 timer_add(struct Timer* timer, EventCallBack call, void* data,
373 enum TimerType type, time_t value)
378 Debug((DEBUG_LIST, "Adding timer %p; time out %Tu (type %s)", timer, value,
379 timer_to_name(type)));
381 /* initialize a timer... */
382 gen_init((struct GenHeader*) timer, call, data, 0, 0);
384 timer->t_type = type;
385 timer->t_value = value;
388 timer_enqueue(timer); /* and enqueue it */
391 /* Remove a timer from the processing queue */
393 timer_del(struct Timer* timer)
397 if (timer->t_header.gh_flags & GEN_MARKED)
398 return; /* timer already marked for destruction */
400 timer->t_header.gh_flags |= GEN_DESTROY;
402 Debug((DEBUG_LIST, "Deleting timer %p (type %s)", timer,
403 timer_to_name(timer->t_type)));
405 if (!timer->t_header.gh_ref) { /* not in use; destroy right now */
407 event_generate(ET_DESTROY, timer, 0);
411 /* Change the time a timer expires */
413 timer_chg(struct Timer* timer, enum TimerType type, time_t value)
417 assert(TT_PERIODIC != timer->t_type);
418 assert(TT_PERIODIC != type);
420 Debug((DEBUG_LIST, "Changing timer %p from type %s timeout %Tu to type %s "
421 "timeout %Tu", timer, timer_to_name(timer->t_type), timer->t_value,
422 timer_to_name(type), value));
424 gen_dequeue(timer); /* remove the timer from the queue */
426 timer->t_type = type; /* Set the new type and value */
427 timer->t_value = value;
430 timer_enqueue(timer); /* re-queue the timer */
433 /* Execute all expired timers */
438 struct Timer* next = 0;
440 /* go through queue... */
441 for (ptr = evInfo.gens.g_timer; ptr; ptr = next) {
442 next = (struct Timer*) ptr->t_header.gh_next;
443 if (CurrentTime < ptr->t_expire)
444 break; /* processed all pending timers */
446 gen_dequeue(ptr); /* must dequeue timer here */
447 if (ptr->t_type == TT_ABSOLUTE || ptr->t_type == TT_RELATIVE) {
448 Debug((DEBUG_LIST, "Marking timer %p for later destruction", ptr));
449 ptr->t_header.gh_flags |= GEN_MARKED; /* mark for destruction */
451 event_generate(ET_EXPIRE, ptr, 0); /* generate expire event */
453 if (ptr->t_header.gh_flags & (GEN_MARKED | GEN_DESTROY)) {
454 Debug((DEBUG_LIST, "Destroying timer %p", ptr));
455 event_generate(ET_DESTROY, ptr, 0);
456 } else if (ptr->t_type == TT_PERIODIC) {
457 Debug((DEBUG_LIST, "Re-enqueuing periodic timer %p", ptr));
458 timer_enqueue(ptr); /* re-queue periodic timer */
463 /* Adds a signal to the event callback system */
465 signal_add(struct Signal* signal, EventCallBack call, void* data, int sig)
467 struct sigaction act;
471 assert(0 != evInfo.engine);
474 gen_init((struct GenHeader*) signal, call, data,
475 (struct GenHeader*) evInfo.gens.g_signal,
476 (struct GenHeader**) &evInfo.gens.g_signal);
478 signal->sig_signal = sig;
480 if (evInfo.engine->eng_signal)
481 (*evInfo.engine->eng_signal)(signal); /* tell engine */
483 act.sa_handler = signal_handler; /* set up signal handler */
485 sigemptyset(&act.sa_mask);
486 sigaction(sig, &act, 0);
490 /* Adds a socket to the event system */
492 socket_add(struct Socket* sock, EventCallBack call, void* data,
493 enum SocketState state, unsigned int events, int fd)
498 assert(0 != evInfo.engine);
499 assert(0 != evInfo.engine->eng_add);
502 gen_init((struct GenHeader*) sock, call, data,
503 (struct GenHeader*) evInfo.gens.g_socket,
504 (struct GenHeader**) &evInfo.gens.g_socket);
506 sock->s_state = state;
507 sock->s_events = events & SOCK_EVENT_MASK;
510 return (*evInfo.engine->eng_add)(sock); /* tell engine about it */
513 /* deletes (or marks for deletion) a socket */
515 socket_del(struct Socket* sock)
518 assert(!(sock->s_header.gh_flags & GEN_DESTROY));
519 assert(0 != evInfo.engine);
520 assert(0 != evInfo.engine->eng_closing);
522 /* tell engine socket is going away */
523 (*evInfo.engine->eng_closing)(sock);
525 sock->s_header.gh_flags |= GEN_DESTROY;
527 if (!sock->s_header.gh_ref) { /* not in use; destroy right now */
529 event_generate(ET_DESTROY, sock, 0);
533 /* Sets the socket state to something else */
535 socket_state(struct Socket* sock, enum SocketState state)
538 assert(0 != evInfo.engine);
539 assert(0 != evInfo.engine->eng_state);
541 /* assertions for invalid socket state transitions */
542 assert(sock->s_state != state); /* not changing states ?! */
543 assert(sock->s_state != SS_LISTENING); /* listening socket to...?! */
544 assert(sock->s_state != SS_CONNECTED); /* connected socket to...?! */
545 /* connecting socket now connected */
546 assert(sock->s_state != SS_CONNECTING || state == SS_CONNECTED);
547 /* unconnected datagram socket now connected */
548 assert(sock->s_state != SS_DATAGRAM || state == SS_CONNECTDG);
549 /* connected datagram socket now unconnected */
550 assert(sock->s_state != SS_CONNECTDG || state == SS_DATAGRAM);
552 if (sock->s_header.gh_flags & GEN_DESTROY) /* socket's been destroyed */
555 /* tell engine we're changing socket state */
556 (*evInfo.engine->eng_state)(sock, state);
558 sock->s_state = state; /* set new state */
561 /* sets the events a socket's interested in */
563 socket_events(struct Socket* sock, unsigned int events)
565 unsigned int new_events = 0;
568 assert(0 != evInfo.engine);
569 assert(0 != evInfo.engine->eng_events);
571 if (sock->s_header.gh_flags & GEN_DESTROY) /* socket's been destroyed */
574 switch (events & SOCK_ACTION_MASK) {
575 case SOCK_ACTION_SET: /* set events to given set */
576 new_events = events & SOCK_EVENT_MASK;
579 case SOCK_ACTION_ADD: /* add some events */
580 new_events = sock->s_events | (events & SOCK_EVENT_MASK);
583 case SOCK_ACTION_DEL: /* remove some events */
584 new_events = sock->s_events & ~(events & SOCK_EVENT_MASK);
588 if (sock->s_events == new_events)
589 return; /* no changes have been made */
591 /* tell engine about event mask change */
592 (*evInfo.engine->eng_events)(sock, new_events);
594 sock->s_events = new_events; /* set new events */
597 /* Returns an engine's name for informational purposes */
601 assert(0 != evInfo.engine);
602 assert(0 != evInfo.engine->eng_name);
604 return evInfo.engine->eng_name;
608 /* These routines pretty-print names for states and types for debug printing */
616 #define NM(name) { #name, name }
621 state_to_name(enum SocketState state)
624 NS(enum SocketState) map[] = {
634 for (i = 0; map[i].name; i++)
635 if (map[i].value == state)
638 return "Undefined socket state";
642 timer_to_name(enum TimerType type)
645 NS(enum TimerType) map[] = {
652 for (i = 0; map[i].name; i++)
653 if (map[i].value == type)
656 return "Undefined timer type";
660 event_to_name(enum EventType type)
663 NS(enum EventType) map[] = {
676 for (i = 0; map[i].name; i++)
677 if (map[i].value == type)
680 return "Undefined event type";
684 gen_flags(unsigned int flags)
687 static char buf[256];
688 NS(unsigned int) map[] = {
696 for (i = 0; map[i].name; i++)
697 if (map[i].value & flags) {
700 loc += ircd_snprintf(0, buf + loc, sizeof(buf) - loc, "%s", map[i].name);
701 if (loc >= sizeof(buf))
702 return buf; /* overflow case */
709 sock_flags(unsigned int flags)
712 static char buf[256];
713 NS(unsigned int) map[] = {
714 NM(SOCK_EVENT_READABLE),
715 NM(SOCK_EVENT_WRITABLE),
724 for (i = 0; map[i].name; i++)
725 if (map[i].value & flags) {
728 loc += ircd_snprintf(0, buf + loc, sizeof(buf) - loc, "%s", map[i].name);
729 if (loc >= sizeof(buf))
730 return buf; /* overflow case */
736 #endif /* DEBUGMODE */