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;
133 (*event->ev_gen.gen_header->gh_call)(event); /* execute the event */
135 /* The logic here is very careful; if the event was an ET_DESTROY,
136 * then we must assume the generator is now invalid; fortunately, we
137 * don't need to do anything to it if so. Otherwise, we decrement
138 * the reference count; if reference count goes to zero, AND we need
139 * to destroy the generator, THEN we generate a DESTROY event.
141 if (event->ev_type != ET_DESTROY)
142 gen_ref_dec(event->ev_gen.gen_header);
144 event->ev_gen.gen_header = 0; /* clear event data */
145 event->ev_type = ET_DESTROY;
147 event->ev_next = evInfo.events_free; /* add to free list */
148 evInfo.events_free = event;
151 #ifndef IRCD_THREADED
152 /* we synchronously execute the event when not threaded */
153 #define event_add(event) \
155 struct Event* _ev = (event); \
157 _ev->ev_prev_p = 0; \
158 event_execute(_ev); \
162 /* add an event to the work queue */
163 /* This is just a placeholder; don't expect ircd to be threaded soon */
164 /* There should be locks all over the place in here */
166 event_add(struct Event* event)
168 struct GenHeader* gen;
172 gen = event->ev_gen.gen_header;
174 /* First, place event on generator's event queue */
177 assert(0 != gen->gh_tail);
179 event->ev_prev_p = &gen->gh_tail->ev_next;
180 gen->gh_tail->ev_next = event;
181 gen->gh_tail = event;
182 } else { /* queue was empty */
183 assert(0 == gen->gh_tail);
185 event->ev_prev_p = &gen->gh_head;
186 gen->gh_head = event;
187 gen->gh_tail = event;
190 /* Now, if the generator isn't on the queue yet... */
191 if (!gen->gh_qprev_p) {
193 if (evInfo.genq_head) {
194 assert(0 != evInfo.genq_tail);
196 gen->gh_qprev_p = &evInfo.genq_tail->gh_qnext;
197 evInfo.genq_tail->gh_qnext = gen;
198 evInfo.genq_tail = gen;
199 } else { /* queue was empty */
200 assert(0 == evInfo.genq_tail);
202 gen->gh_qprev_p = &evInfo.genq_head;
203 evInfo.genq_head = gen;
204 evInfo.genq_tail = gen;
207 /* We'd also have to signal the work crew here */
210 #endif /* IRCD_THREADED */
212 /* Place a timer in the correct spot on the queue */
214 timer_enqueue(struct Timer* timer)
216 struct Timer** ptr_p;
219 assert(0 == timer->t_header.gh_prev_p); /* not already on queue */
221 /* Calculate expire time */
222 switch (timer->t_type) {
223 case TT_ABSOLUTE: /* no need to consider it relative */
224 timer->t_expire = timer->t_value;
227 case TT_RELATIVE: case TT_PERIODIC: /* relative timer */
228 timer->t_expire = timer->t_value + CurrentTime;
232 /* Find a slot to insert timer */
233 for (ptr_p = &evInfo.gens.g_timer; ;
234 ptr_p = (struct Timer**) &(*ptr_p)->t_header.gh_next)
235 if (!*ptr_p || timer->t_expire < (*ptr_p)->t_expire)
238 /* link it in the right place */
239 timer->t_header.gh_next = (struct GenHeader*) *ptr_p;
240 timer->t_header.gh_prev_p = (struct GenHeader**) ptr_p;
242 (*ptr_p)->t_header.gh_prev_p = &timer->t_header.gh_next;
246 /* signal handler for writing signal notification to pipe */
248 signal_handler(int sig)
252 assert(sigInfo.fd >= 0);
254 c = (unsigned char) sig; /* only write 1 byte to identify sig */
256 write(sigInfo.fd, &c, 1);
259 /* callback for signal "socket" events */
261 signal_callback(struct Event* event)
263 unsigned char sigstr[SIGS_PER_SOCK];
267 assert(event->ev_type == ET_READ); /* readable events only */
269 n_sigs = read(event->ev_gen.gen_socket->s_fd, sigstr, sizeof(sigstr));
271 for (i = 0; i < n_sigs; i++) {
272 sig = (int) sigstr[i]; /* get signal */
274 for (ptr = evInfo.gens.g_signal; ptr;
275 ptr = (struct Signal*) ptr->sig_header.gh_next)
276 if (ptr->sig_signal == sig) /* find its descriptor... */
280 event_generate(ET_SIGNAL, ptr, sig); /* generate signal event */
284 /* Remove something from its queue */
286 gen_dequeue(void* arg)
288 struct GenHeader* gen = (struct GenHeader*) arg;
290 if (gen->gh_next) /* clip it out of the list */
291 gen->gh_next->gh_prev_p = gen->gh_prev_p;
293 *gen->gh_prev_p = gen->gh_next;
295 gen->gh_next = 0; /* mark that it's not in the list anymore */
299 /* Initializes the event system */
301 event_init(int max_sockets)
305 for (i = 0; evEngines[i]; i++) { /* look for an engine... */
306 assert(0 != evEngines[i]->eng_name);
307 assert(0 != evEngines[i]->eng_init);
309 if ((*evEngines[i]->eng_init)(max_sockets))
310 break; /* Found an engine that'll work */
313 assert(0 != evEngines[i]);
315 evInfo.engine = evEngines[i]; /* save engine */
317 if (!evInfo.engine->eng_signal) { /* engine can't do signals */
319 log_write(LS_SYSTEM, L_CRIT, 0, "Failed to open signal pipe");
323 sigInfo.fd = p[1]; /* write end of pipe */
324 socket_add(&sigInfo.sock, signal_callback, 0, SS_NOTSOCK,
325 SOCK_EVENT_READABLE, p[0]); /* read end of pipe */
329 /* Do the event loop */
333 assert(0 != evInfo.engine);
334 assert(0 != evInfo.engine->eng_loop);
336 (*evInfo.engine->eng_loop)(&evInfo.gens);
339 /* Generate an event and add it to the queue (or execute it) */
341 event_generate(enum EventType type, void* arg, int data)
344 struct GenHeader* gen = (struct GenHeader*) arg;
348 /* don't create events (other than ET_DESTROY) for destroyed generators */
349 if (type != ET_DESTROY && (gen->gh_flags & GEN_DESTROY))
352 Debug((DEBUG_LIST, "Generating event type %s for generator %p (%s)",
353 event_to_name(type), gen, gen_flags(gen->gh_flags)));
355 if ((ptr = evInfo.events_free))
356 evInfo.events_free = ptr->ev_next; /* pop one off the freelist */
357 else { /* allocate another structure */
358 ptr = (struct Event*) MyMalloc(sizeof(struct Event));
359 evInfo.events_alloc++; /* count of allocated events */
362 ptr->ev_type = type; /* Record event type */
365 ptr->ev_gen.gen_header = (struct GenHeader*) gen;
366 ptr->ev_gen.gen_header->gh_ref++;
368 event_add(ptr); /* add event to queue */
371 /* Add a timer to be processed */
373 timer_add(struct Timer* timer, EventCallBack call, void* data,
374 enum TimerType type, time_t value)
379 Debug((DEBUG_LIST, "Adding timer %p; time out %Tu (type %s)", timer, value,
380 timer_to_name(type)));
382 /* initialize a timer... */
383 gen_init((struct GenHeader*) timer, call, data, 0, 0);
385 timer->t_type = type;
386 timer->t_value = value;
389 timer_enqueue(timer); /* and enqueue it */
392 /* Remove a timer from the processing queue */
394 timer_del(struct Timer* timer)
398 if (timer->t_header.gh_flags & GEN_MARKED)
399 return; /* timer already marked for destruction */
401 timer->t_header.gh_flags |= GEN_DESTROY;
403 Debug((DEBUG_LIST, "Deleting timer %p (type %s)", timer,
404 timer_to_name(timer->t_type)));
406 if (!timer->t_header.gh_ref) { /* not in use; destroy right now */
408 event_generate(ET_DESTROY, timer, 0);
412 /* Change the time a timer expires */
414 timer_chg(struct Timer* timer, enum TimerType type, time_t value)
418 assert(TT_PERIODIC != timer->t_type);
419 assert(TT_PERIODIC != type);
421 Debug((DEBUG_LIST, "Changing timer %p from type %s timeout %Tu to type %s "
422 "timeout %Tu", timer, timer_to_name(timer->t_type), timer->t_value,
423 timer_to_name(type), value));
425 gen_dequeue(timer); /* remove the timer from the queue */
427 timer->t_type = type; /* Set the new type and value */
428 timer->t_value = value;
431 timer_enqueue(timer); /* re-queue the timer */
434 /* Execute all expired timers */
439 struct Timer* next = 0;
441 /* go through queue... */
442 for (ptr = evInfo.gens.g_timer; ptr; ptr = next) {
443 next = (struct Timer*) ptr->t_header.gh_next;
444 if (CurrentTime < ptr->t_expire)
445 break; /* processed all pending timers */
447 gen_dequeue(ptr); /* must dequeue timer here */
448 if (ptr->t_type == TT_ABSOLUTE || ptr->t_type == TT_RELATIVE) {
449 Debug((DEBUG_LIST, "Marking timer %p for later destruction", ptr));
450 ptr->t_header.gh_flags |= GEN_MARKED; /* mark for destruction */
452 event_generate(ET_EXPIRE, ptr, 0); /* generate expire event */
454 if (ptr->t_header.gh_flags & (GEN_MARKED | GEN_DESTROY)) {
455 Debug((DEBUG_LIST, "Destroying timer %p", ptr));
456 event_generate(ET_DESTROY, ptr, 0);
457 } else if (ptr->t_type == TT_PERIODIC) {
458 Debug((DEBUG_LIST, "Re-enqueuing periodic timer %p", ptr));
459 timer_enqueue(ptr); /* re-queue periodic timer */
464 /* Adds a signal to the event callback system */
466 signal_add(struct Signal* signal, EventCallBack call, void* data, int sig)
468 struct sigaction act;
472 assert(0 != evInfo.engine);
475 gen_init((struct GenHeader*) signal, call, data,
476 (struct GenHeader*) evInfo.gens.g_signal,
477 (struct GenHeader**) &evInfo.gens.g_signal);
479 signal->sig_signal = sig;
481 if (evInfo.engine->eng_signal)
482 (*evInfo.engine->eng_signal)(signal); /* tell engine */
484 act.sa_handler = signal_handler; /* set up signal handler */
486 sigemptyset(&act.sa_mask);
487 sigaction(sig, &act, 0);
491 /* Adds a socket to the event system */
493 socket_add(struct Socket* sock, EventCallBack call, void* data,
494 enum SocketState state, unsigned int events, int fd)
499 assert(0 != evInfo.engine);
500 assert(0 != evInfo.engine->eng_add);
503 gen_init((struct GenHeader*) sock, call, data,
504 (struct GenHeader*) evInfo.gens.g_socket,
505 (struct GenHeader**) &evInfo.gens.g_socket);
507 sock->s_state = state;
508 sock->s_events = events & SOCK_EVENT_MASK;
511 return (*evInfo.engine->eng_add)(sock); /* tell engine about it */
514 /* deletes (or marks for deletion) a socket */
516 socket_del(struct Socket* sock)
519 assert(!(sock->s_header.gh_flags & GEN_DESTROY));
520 assert(0 != evInfo.engine);
521 assert(0 != evInfo.engine->eng_closing);
523 /* tell engine socket is going away */
524 (*evInfo.engine->eng_closing)(sock);
526 sock->s_header.gh_flags |= GEN_DESTROY;
528 if (!sock->s_header.gh_ref) { /* not in use; destroy right now */
530 event_generate(ET_DESTROY, sock, 0);
534 /* Sets the socket state to something else */
536 socket_state(struct Socket* sock, enum SocketState state)
539 assert(0 != evInfo.engine);
540 assert(0 != evInfo.engine->eng_state);
542 /* assertions for invalid socket state transitions */
543 assert(sock->s_state != state); /* not changing states ?! */
544 assert(sock->s_state != SS_LISTENING); /* listening socket to...?! */
545 assert(sock->s_state != SS_CONNECTED); /* connected socket to...?! */
546 /* connecting socket now connected */
547 assert(sock->s_state != SS_CONNECTING || state == SS_CONNECTED);
548 /* unconnected datagram socket now connected */
549 assert(sock->s_state != SS_DATAGRAM || state == SS_CONNECTDG);
550 /* connected datagram socket now unconnected */
551 assert(sock->s_state != SS_CONNECTDG || state == SS_DATAGRAM);
553 if (sock->s_header.gh_flags & GEN_DESTROY) /* socket's been destroyed */
556 /* tell engine we're changing socket state */
557 (*evInfo.engine->eng_state)(sock, state);
559 sock->s_state = state; /* set new state */
562 /* sets the events a socket's interested in */
564 socket_events(struct Socket* sock, unsigned int events)
566 unsigned int new_events = 0;
569 assert(0 != evInfo.engine);
570 assert(0 != evInfo.engine->eng_events);
572 if (sock->s_header.gh_flags & GEN_DESTROY) /* socket's been destroyed */
575 switch (events & SOCK_ACTION_MASK) {
576 case SOCK_ACTION_SET: /* set events to given set */
577 new_events = events & SOCK_EVENT_MASK;
580 case SOCK_ACTION_ADD: /* add some events */
581 new_events = sock->s_events | (events & SOCK_EVENT_MASK);
584 case SOCK_ACTION_DEL: /* remove some events */
585 new_events = sock->s_events & ~(events & SOCK_EVENT_MASK);
589 if (sock->s_events == new_events)
590 return; /* no changes have been made */
592 /* tell engine about event mask change */
593 (*evInfo.engine->eng_events)(sock, new_events);
595 sock->s_events = new_events; /* set new events */
598 /* Returns an engine's name for informational purposes */
602 assert(0 != evInfo.engine);
603 assert(0 != evInfo.engine->eng_name);
605 return evInfo.engine->eng_name;
609 /* These routines pretty-print names for states and types for debug printing */
617 #define NM(name) { #name, name }
622 state_to_name(enum SocketState state)
625 NS(enum SocketState) map[] = {
635 for (i = 0; map[i].name; i++)
636 if (map[i].value == state)
639 return "Undefined socket state";
643 timer_to_name(enum TimerType type)
646 NS(enum TimerType) map[] = {
653 for (i = 0; map[i].name; i++)
654 if (map[i].value == type)
657 return "Undefined timer type";
661 event_to_name(enum EventType type)
664 NS(enum EventType) map[] = {
677 for (i = 0; map[i].name; i++)
678 if (map[i].value == type)
681 return "Undefined event type";
685 gen_flags(unsigned int flags)
688 static char buf[256];
689 NS(unsigned int) map[] = {
697 for (i = 0; map[i].name; i++)
698 if (map[i].value & flags) {
701 loc += ircd_snprintf(0, buf + loc, sizeof(buf) - loc, "%s", map[i].name);
702 if (loc >= sizeof(buf))
703 return buf; /* overflow case */
710 sock_flags(unsigned int flags)
713 static char buf[256];
714 NS(unsigned int) map[] = {
715 NM(SOCK_EVENT_READABLE),
716 NM(SOCK_EVENT_WRITABLE),
725 for (i = 0; map[i].name; i++)
726 if (map[i].value & flags) {
729 loc += ircd_snprintf(0, buf + loc, sizeof(buf) - loc, "%s", map[i].name);
730 if (loc >= sizeof(buf))
731 return buf; /* overflow case */
737 #endif /* DEBUGMODE */