xref: /illumos-gate/usr/src/lib/libresolv2/common/isc/ev_timers.c (revision 069e6b7e31ba5dcbc5441b98af272714d9a5455c) 
1 /*
2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (c) 1995-1999 by Internet Software Consortium
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /* ev_timers.c - implement timers for the eventlib
19  * vix 09sep95 [initial]
20  */
21 
22 #include "port_before.h"
23 #include "fd_setsize.h"
24 
25 #include <errno.h>
26 
27 #include <isc/assertions.h>
28 #include <isc/eventlib.h>
29 #include "eventlib_p.h"
30 
31 #include "port_after.h"
32 
33 /* Constants. */
34 
35 #define	MILLION 1000000
36 #define BILLION 1000000000
37 
38 /* Forward. */
39 
40 static int due_sooner(void *, void *);
41 static void set_index(void *, int);
42 static void free_timer(void *, void *);
43 static void print_timer(void *, void *);
44 static void idle_timeout(evContext, void *, struct timespec, struct timespec);
45 
46 /* Private type. */
47 
48 typedef struct {
49 	evTimerFunc	func;
50 	void *		uap;
51 	struct timespec	lastTouched;
52 	struct timespec	max_idle;
53 	evTimer *	timer;
54 } idle_timer;
55 
56 /* Public. */
57 
58 struct timespec
59 evConsTime(time_t sec, long nsec) {
60 	struct timespec x;
61 
62 	x.tv_sec = sec;
63 	x.tv_nsec = nsec;
64 	return (x);
65 }
66 
67 struct timespec
68 evAddTime(struct timespec addend1, struct timespec addend2) {
69 	struct timespec x;
70 
71 	x.tv_sec = addend1.tv_sec + addend2.tv_sec;
72 	x.tv_nsec = addend1.tv_nsec + addend2.tv_nsec;
73 	if (x.tv_nsec >= BILLION) {
74 		x.tv_sec++;
75 		x.tv_nsec -= BILLION;
76 	}
77 	return (x);
78 }
79 
80 struct timespec
81 evSubTime(struct timespec minuend, struct timespec subtrahend) {
82 	struct timespec x;
83 
84 	x.tv_sec = minuend.tv_sec - subtrahend.tv_sec;
85 	if (minuend.tv_nsec >= subtrahend.tv_nsec)
86 		x.tv_nsec = minuend.tv_nsec - subtrahend.tv_nsec;
87 	else {
88 		x.tv_nsec = BILLION - subtrahend.tv_nsec + minuend.tv_nsec;
89 		x.tv_sec--;
90 	}
91 	return (x);
92 }
93 
94 int
95 evCmpTime(struct timespec a, struct timespec b) {
96 	long x = a.tv_sec - b.tv_sec;
97 
98 	if (x == 0L)
99 		x = a.tv_nsec - b.tv_nsec;
100 	return (x < 0L ? (-1) : x > 0L ? (1) : (0));
101 }
102 
103 struct timespec
104 evNowTime() {
105 	struct timeval now;
106 #ifdef CLOCK_REALTIME
107 	struct timespec tsnow;
108 	int m = CLOCK_REALTIME;
109 
110 #ifdef CLOCK_MONOTONIC
111 	if (__evOptMonoTime)
112 		m = CLOCK_MONOTONIC;
113 #endif
114 	if (clock_gettime(m, &tsnow) == 0)
115 		return (tsnow);
116 #endif
117 	if (gettimeofday(&now, NULL) < 0)
118 		return (evConsTime(0, 0));
119 	return (evTimeSpec(now));
120 }
121 
122 struct timespec
123 evUTCTime() {
124 	struct timeval now;
125 #ifdef CLOCK_REALTIME
126 	struct timespec tsnow;
127 	if (clock_gettime(CLOCK_REALTIME, &tsnow) == 0)
128 		return (tsnow);
129 #endif
130 	if (gettimeofday(&now, NULL) < 0)
131 		return (evConsTime(0, 0));
132 	return (evTimeSpec(now));
133 }
134 
135 struct timespec
136 evLastEventTime(evContext opaqueCtx) {
137 	evContext_p *ctx = opaqueCtx.opaque;
138 
139 	return (ctx->lastEventTime);
140 }
141 
142 struct timespec
143 evTimeSpec(struct timeval tv) {
144 	struct timespec ts;
145 
146 	ts.tv_sec = tv.tv_sec;
147 	ts.tv_nsec = tv.tv_usec * 1000;
148 	return (ts);
149 }
150 
151 struct timeval
152 evTimeVal(struct timespec ts) {
153 	struct timeval tv;
154 
155 	tv.tv_sec = ts.tv_sec;
156 	tv.tv_usec = ts.tv_nsec / 1000;
157 	return (tv);
158 }
159 
160 int
161 evSetTimer(evContext opaqueCtx,
162 	   evTimerFunc func,
163 	   void *uap,
164 	   struct timespec due,
165 	   struct timespec inter,
166 	   evTimerID *opaqueID
167 ) {
168 	evContext_p *ctx = opaqueCtx.opaque;
169 	evTimer *id;
170 
171 	evPrintf(ctx, 1,
172 "evSetTimer(ctx %p, func %p, uap %p, due %ld.%09ld, inter %ld.%09ld)\n",
173 		 ctx, func, uap,
174 		 (long)due.tv_sec, due.tv_nsec,
175 		 (long)inter.tv_sec, inter.tv_nsec);
176 
177 #ifdef __hpux
178 	/*
179 	 * tv_sec and tv_nsec are unsigned.
180 	 */
181 	if (due.tv_nsec >= BILLION)
182 		EV_ERR(EINVAL);
183 
184 	if (inter.tv_nsec >= BILLION)
185 		EV_ERR(EINVAL);
186 #else
187 	if (due.tv_sec < 0 || due.tv_nsec < 0 || due.tv_nsec >= BILLION)
188 		EV_ERR(EINVAL);
189 
190 	if (inter.tv_sec < 0 || inter.tv_nsec < 0 || inter.tv_nsec >= BILLION)
191 		EV_ERR(EINVAL);
192 #endif
193 
194 	/* due={0,0} is a magic cookie meaning "now." */
195 	if (due.tv_sec == (time_t)0 && due.tv_nsec == 0L)
196 		due = evNowTime();
197 
198 	/* Allocate and fill. */
199 	OKNEW(id);
200 	id->func = func;
201 	id->uap = uap;
202 	id->due = due;
203 	id->inter = inter;
204 
205 	if (heap_insert(ctx->timers, id) < 0)
206 		return (-1);
207 
208 	/* Remember the ID if the caller provided us a place for it. */
209 	if (opaqueID)
210 		opaqueID->opaque = id;
211 
212 	if (ctx->debug > 7) {
213 		evPrintf(ctx, 7, "timers after evSetTimer:\n");
214 		(void) heap_for_each(ctx->timers, print_timer, (void *)ctx);
215 	}
216 
217 	return (0);
218 }
219 
220 int
221 evClearTimer(evContext opaqueCtx, evTimerID id) {
222 	evContext_p *ctx = opaqueCtx.opaque;
223 	evTimer *del = id.opaque;
224 
225 	if (ctx->cur != NULL &&
226 	    ctx->cur->type == Timer &&
227 	    ctx->cur->u.timer.this == del) {
228 		evPrintf(ctx, 8, "deferring delete of timer (executing)\n");
229 		/*
230 		 * Setting the interval to zero ensures that evDrop() will
231 		 * clean up the timer.
232 		 */
233 		del->inter = evConsTime(0, 0);
234 		return (0);
235 	}
236 
237 	if (heap_element(ctx->timers, del->index) != del)
238 		EV_ERR(ENOENT);
239 
240 	if (heap_delete(ctx->timers, del->index) < 0)
241 		return (-1);
242 	FREE(del);
243 
244 	if (ctx->debug > 7) {
245 		evPrintf(ctx, 7, "timers after evClearTimer:\n");
246 		(void) heap_for_each(ctx->timers, print_timer, (void *)ctx);
247 	}
248 
249 	return (0);
250 }
251 
252 int
253 evConfigTimer(evContext opaqueCtx,
254 	     evTimerID id,
255 	     const char *param,
256 	     int value
257 ) {
258 	evContext_p *ctx = opaqueCtx.opaque;
259 	evTimer *timer = id.opaque;
260 	int result=0;
261 
262 	UNUSED(value);
263 
264 	if (heap_element(ctx->timers, timer->index) != timer)
265 		EV_ERR(ENOENT);
266 
267 	if (strcmp(param, "rate") == 0)
268 		timer->mode |= EV_TMR_RATE;
269 	else if (strcmp(param, "interval") == 0)
270 		timer->mode &= ~EV_TMR_RATE;
271 	else
272 		EV_ERR(EINVAL);
273 
274 	return (result);
275 }
276 
277 int
278 evResetTimer(evContext opaqueCtx,
279 	     evTimerID id,
280 	     evTimerFunc func,
281 	     void *uap,
282 	     struct timespec due,
283 	     struct timespec inter
284 ) {
285 	evContext_p *ctx = opaqueCtx.opaque;
286 	evTimer *timer = id.opaque;
287 	struct timespec old_due;
288 	int result=0;
289 
290 	if (heap_element(ctx->timers, timer->index) != timer)
291 		EV_ERR(ENOENT);
292 
293 #ifdef __hpux
294 	/*
295 	 * tv_sec and tv_nsec are unsigned.
296 	 */
297 	if (due.tv_nsec >= BILLION)
298 		EV_ERR(EINVAL);
299 
300 	if (inter.tv_nsec >= BILLION)
301 		EV_ERR(EINVAL);
302 #else
303 	if (due.tv_sec < 0 || due.tv_nsec < 0 || due.tv_nsec >= BILLION)
304 		EV_ERR(EINVAL);
305 
306 	if (inter.tv_sec < 0 || inter.tv_nsec < 0 || inter.tv_nsec >= BILLION)
307 		EV_ERR(EINVAL);
308 #endif
309 
310 	old_due = timer->due;
311 
312 	timer->func = func;
313 	timer->uap = uap;
314 	timer->due = due;
315 	timer->inter = inter;
316 
317 	switch (evCmpTime(due, old_due)) {
318 	case -1:
319 		result = heap_increased(ctx->timers, timer->index);
320 		break;
321 	case 0:
322 		result = 0;
323 		break;
324 	case 1:
325 		result = heap_decreased(ctx->timers, timer->index);
326 		break;
327 	}
328 
329 	if (ctx->debug > 7) {
330 		evPrintf(ctx, 7, "timers after evResetTimer:\n");
331 		(void) heap_for_each(ctx->timers, print_timer, (void *)ctx);
332 	}
333 
334 	return (result);
335 }
336 
337 int
338 evSetIdleTimer(evContext opaqueCtx,
339 		evTimerFunc func,
340 		void *uap,
341 		struct timespec max_idle,
342 		evTimerID *opaqueID
343 ) {
344 	evContext_p *ctx = opaqueCtx.opaque;
345 	idle_timer *tt;
346 
347 	/* Allocate and fill. */
348 	OKNEW(tt);
349 	tt->func = func;
350 	tt->uap = uap;
351 	tt->lastTouched = ctx->lastEventTime;
352 	tt->max_idle = max_idle;
353 
354 	if (evSetTimer(opaqueCtx, idle_timeout, tt,
355 		       evAddTime(ctx->lastEventTime, max_idle),
356 		       max_idle, opaqueID) < 0) {
357 		FREE(tt);
358 		return (-1);
359 	}
360 
361 	tt->timer = opaqueID->opaque;
362 
363 	return (0);
364 }
365 
366 int
367 evClearIdleTimer(evContext opaqueCtx, evTimerID id) {
368 	evTimer *del = id.opaque;
369 	idle_timer *tt = del->uap;
370 
371 	FREE(tt);
372 	return (evClearTimer(opaqueCtx, id));
373 }
374 
375 int
376 evResetIdleTimer(evContext opaqueCtx,
377 		 evTimerID opaqueID,
378 		 evTimerFunc func,
379 		 void *uap,
380 		 struct timespec max_idle
381 ) {
382 	evContext_p *ctx = opaqueCtx.opaque;
383 	evTimer *timer = opaqueID.opaque;
384 	idle_timer *tt = timer->uap;
385 
386 	tt->func = func;
387 	tt->uap = uap;
388 	tt->lastTouched = ctx->lastEventTime;
389 	tt->max_idle = max_idle;
390 
391 	return (evResetTimer(opaqueCtx, opaqueID, idle_timeout, tt,
392 			     evAddTime(ctx->lastEventTime, max_idle),
393 			     max_idle));
394 }
395 
396 int
397 evTouchIdleTimer(evContext opaqueCtx, evTimerID id) {
398 	evContext_p *ctx = opaqueCtx.opaque;
399 	evTimer *t = id.opaque;
400 	idle_timer *tt = t->uap;
401 
402 	tt->lastTouched = ctx->lastEventTime;
403 
404 	return (0);
405 }
406 
407 /* Public to the rest of eventlib. */
408 
409 heap_context
410 evCreateTimers(const evContext_p *ctx) {
411 
412 	UNUSED(ctx);
413 
414 	return (heap_new(due_sooner, set_index, 2048));
415 }
416 
417 void
418 evDestroyTimers(const evContext_p *ctx) {
419 	(void) heap_for_each(ctx->timers, free_timer, NULL);
420 	(void) heap_free(ctx->timers);
421 }
422 
423 /* Private. */
424 
425 static int
426 due_sooner(void *a, void *b) {
427 	evTimer *a_timer, *b_timer;
428 
429 	a_timer = a;
430 	b_timer = b;
431 	return (evCmpTime(a_timer->due, b_timer->due) < 0);
432 }
433 
434 static void
435 set_index(void *what, int index) {
436 	evTimer *timer;
437 
438 	timer = what;
439 	timer->index = index;
440 }
441 
442 static void
443 free_timer(void *what, void *uap) {
444 	evTimer *t = what;
445 
446 	UNUSED(uap);
447 
448 	FREE(t);
449 }
450 
451 static void
452 print_timer(void *what, void *uap) {
453 	evTimer *cur = what;
454 	evContext_p *ctx = uap;
455 
456 	cur = what;
457 	evPrintf(ctx, 7,
458 	    "  func %p, uap %p, due %ld.%09ld, inter %ld.%09ld\n",
459 		 cur->func, cur->uap,
460 		 (long)cur->due.tv_sec, cur->due.tv_nsec,
461 		 (long)cur->inter.tv_sec, cur->inter.tv_nsec);
462 }
463 
464 static void
465 idle_timeout(evContext opaqueCtx,
466 	     void *uap,
467 	     struct timespec due,
468 	     struct timespec inter
469 ) {
470 	evContext_p *ctx = opaqueCtx.opaque;
471 	idle_timer *this = uap;
472 	struct timespec idle;
473 
474 	UNUSED(due);
475 	UNUSED(inter);
476 
477 	idle = evSubTime(ctx->lastEventTime, this->lastTouched);
478 	if (evCmpTime(idle, this->max_idle) >= 0) {
479 		(this->func)(opaqueCtx, this->uap, this->timer->due,
480 			     this->max_idle);
481 		/*
482 		 * Setting the interval to zero will cause the timer to
483 		 * be cleaned up in evDrop().
484 		 */
485 		this->timer->inter = evConsTime(0, 0);
486 		FREE(this);
487 	} else {
488 		/* evDrop() will reschedule the timer. */
489 		this->timer->inter = evSubTime(this->max_idle, idle);
490 	}
491 }
492 
493 /*! \file */
494