Line data Source code
1 : /*
2 : Unix SMB/CIFS implementation.
3 :
4 : common events code for timed events
5 :
6 : Copyright (C) Andrew Tridgell 2003-2006
7 : Copyright (C) Stefan Metzmacher 2005-2009
8 :
9 : ** NOTE! The following LGPL license applies to the tevent
10 : ** library. This does NOT imply that all of Samba is released
11 : ** under the LGPL
12 :
13 : This library is free software; you can redistribute it and/or
14 : modify it under the terms of the GNU Lesser General Public
15 : License as published by the Free Software Foundation; either
16 : version 3 of the License, or (at your option) any later version.
17 :
18 : This library is distributed in the hope that it will be useful,
19 : but WITHOUT ANY WARRANTY; without even the implied warranty of
20 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21 : Lesser General Public License for more details.
22 :
23 : You should have received a copy of the GNU Lesser General Public
24 : License along with this library; if not, see <http://www.gnu.org/licenses/>.
25 : */
26 :
27 : #include "replace.h"
28 : #include "system/time.h"
29 : #define TEVENT_DEPRECATED 1
30 : #include "tevent.h"
31 : #include "tevent_internal.h"
32 : #include "tevent_util.h"
33 :
34 : /**
35 : compare two timeval structures.
36 : Return -1 if tv1 < tv2
37 : Return 0 if tv1 == tv2
38 : Return 1 if tv1 > tv2
39 : */
40 530989922 : int tevent_timeval_compare(const struct timeval *tv1, const struct timeval *tv2)
41 : {
42 530989922 : if (tv1->tv_sec > tv2->tv_sec) return 1;
43 346393963 : if (tv1->tv_sec < tv2->tv_sec) return -1;
44 143560345 : if (tv1->tv_usec > tv2->tv_usec) return 1;
45 138706568 : if (tv1->tv_usec < tv2->tv_usec) return -1;
46 129899029 : return 0;
47 : }
48 :
49 : /**
50 : return a zero timeval
51 : */
52 612072224 : struct timeval tevent_timeval_zero(void)
53 : {
54 40818764 : struct timeval tv;
55 612072224 : tv.tv_sec = 0;
56 612072224 : tv.tv_usec = 0;
57 612072224 : return tv;
58 : }
59 :
60 : /**
61 : return a timeval for the current time
62 : */
63 325861139 : struct timeval tevent_timeval_current(void)
64 : {
65 31430136 : struct timeval tv;
66 325861139 : gettimeofday(&tv, NULL);
67 325861139 : return tv;
68 : }
69 :
70 : /**
71 : return a timeval struct with the given elements
72 : */
73 29051015 : struct timeval tevent_timeval_set(uint32_t secs, uint32_t usecs)
74 : {
75 428467 : struct timeval tv;
76 29051015 : tv.tv_sec = secs;
77 29051015 : tv.tv_usec = usecs;
78 29051015 : return tv;
79 : }
80 :
81 : /**
82 : return the difference between two timevals as a timeval
83 : if tv1 comes after tv2, then return a zero timeval
84 : (this is *tv2 - *tv1)
85 : */
86 172201238 : struct timeval tevent_timeval_until(const struct timeval *tv1,
87 : const struct timeval *tv2)
88 : {
89 28991293 : struct timeval t;
90 172201238 : if (tevent_timeval_compare(tv1, tv2) >= 0) {
91 1832348 : return tevent_timeval_zero();
92 : }
93 170368890 : t.tv_sec = tv2->tv_sec - tv1->tv_sec;
94 170368890 : if (tv1->tv_usec > tv2->tv_usec) {
95 138779997 : t.tv_sec--;
96 138779997 : t.tv_usec = 1000000 - (tv1->tv_usec - tv2->tv_usec);
97 : } else {
98 31588893 : t.tv_usec = tv2->tv_usec - tv1->tv_usec;
99 : }
100 170368890 : return t;
101 : }
102 :
103 : /**
104 : return true if a timeval is zero
105 : */
106 1368204927 : bool tevent_timeval_is_zero(const struct timeval *tv)
107 : {
108 1368204927 : return tv->tv_sec == 0 && tv->tv_usec == 0;
109 : }
110 :
111 34748071 : struct timeval tevent_timeval_add(const struct timeval *tv, uint32_t secs,
112 : uint32_t usecs)
113 : {
114 34748071 : struct timeval tv2 = *tv;
115 34748071 : tv2.tv_sec += secs;
116 34748071 : tv2.tv_usec += usecs;
117 34748071 : tv2.tv_sec += tv2.tv_usec / 1000000;
118 34748071 : tv2.tv_usec = tv2.tv_usec % 1000000;
119 :
120 34748071 : return tv2;
121 : }
122 :
123 : /**
124 : return a timeval in the future with a specified offset
125 : */
126 34741483 : struct timeval tevent_timeval_current_ofs(uint32_t secs, uint32_t usecs)
127 : {
128 34741483 : struct timeval tv = tevent_timeval_current();
129 34741483 : return tevent_timeval_add(&tv, secs, usecs);
130 : }
131 :
132 : /*
133 : destroy a timed event
134 : */
135 417584868 : static int tevent_common_timed_destructor(struct tevent_timer *te)
136 : {
137 417584868 : if (te->destroyed) {
138 123195 : tevent_common_check_double_free(te, "tevent_timer double free");
139 123195 : goto done;
140 : }
141 417461673 : te->destroyed = true;
142 :
143 417461673 : if (te->event_ctx == NULL) {
144 90746 : return 0;
145 : }
146 :
147 417368873 : TEVENT_DEBUG(te->event_ctx, TEVENT_DEBUG_TRACE,
148 : "Destroying timer event %p \"%s\"\n",
149 : te, te->handler_name);
150 :
151 417368873 : if (te->event_ctx->last_zero_timer == te) {
152 27276 : te->event_ctx->last_zero_timer = DLIST_PREV(te);
153 : }
154 :
155 417368873 : tevent_trace_timer_callback(te->event_ctx, te, TEVENT_EVENT_TRACE_DETACH);
156 417368873 : DLIST_REMOVE(te->event_ctx->timer_events, te);
157 :
158 417368873 : te->event_ctx = NULL;
159 417492068 : done:
160 417492068 : if (te->busy) {
161 199918957 : return -1;
162 : }
163 211873741 : te->wrapper = NULL;
164 :
165 211873741 : return 0;
166 : }
167 :
168 450434169 : static void tevent_common_insert_timer(struct tevent_context *ev,
169 : struct tevent_timer *te,
170 : bool optimize_zero)
171 : {
172 450434169 : struct tevent_timer *prev_te = NULL;
173 :
174 450434169 : if (te->destroyed) {
175 0 : tevent_abort(ev, "tevent_timer use after free");
176 0 : return;
177 : }
178 :
179 : /* keep the list ordered */
180 450434169 : if (optimize_zero && tevent_timeval_is_zero(&te->next_event)) {
181 : /*
182 : * Some callers use zero tevent_timer
183 : * instead of tevent_immediate events.
184 : *
185 : * As these can happen very often,
186 : * we remember the last zero timer
187 : * in the list.
188 : */
189 203727019 : prev_te = ev->last_zero_timer;
190 203727019 : ev->last_zero_timer = te;
191 : } else {
192 6072161 : struct tevent_timer *cur_te;
193 :
194 : /*
195 : * we traverse the list from the tail
196 : * because it's much more likely that
197 : * timers are added at the end of the list
198 : */
199 246707150 : for (cur_te = DLIST_TAIL(ev->timer_events);
200 284869137 : cur_te != NULL;
201 38423669 : cur_te = DLIST_PREV(cur_te))
202 : {
203 6376997 : int ret;
204 :
205 : /*
206 : * if the new event comes before the current
207 : * we continue searching
208 : */
209 253117610 : ret = tevent_timeval_compare(&te->next_event,
210 246740613 : &cur_te->next_event);
211 246740613 : if (ret < 0) {
212 38423669 : continue;
213 : }
214 :
215 202529033 : break;
216 : }
217 :
218 240634989 : prev_te = cur_te;
219 : }
220 :
221 450434169 : tevent_trace_timer_callback(te->event_ctx, te, TEVENT_EVENT_TRACE_ATTACH);
222 450434169 : DLIST_ADD_AFTER(ev->timer_events, te, prev_te);
223 : }
224 :
225 : /*
226 : add a timed event
227 : return NULL on failure (memory allocation error)
228 : */
229 417595125 : static struct tevent_timer *tevent_common_add_timer_internal(
230 : struct tevent_context *ev,
231 : TALLOC_CTX *mem_ctx,
232 : struct timeval next_event,
233 : tevent_timer_handler_t handler,
234 : void *private_data,
235 : const char *handler_name,
236 : const char *location,
237 : bool optimize_zero)
238 : {
239 11517315 : struct tevent_timer *te;
240 :
241 417595166 : te = talloc(mem_ctx?mem_ctx:ev, struct tevent_timer);
242 417595125 : if (te == NULL) return NULL;
243 :
244 417595125 : *te = (struct tevent_timer) {
245 : .event_ctx = ev,
246 : .next_event = next_event,
247 : .handler = handler,
248 : .private_data = private_data,
249 : .handler_name = handler_name,
250 : .location = location,
251 : };
252 :
253 417595125 : if (ev->timer_events == NULL) {
254 76600181 : ev->last_zero_timer = NULL;
255 : }
256 :
257 417595125 : tevent_common_insert_timer(ev, te, optimize_zero);
258 :
259 417595125 : talloc_set_destructor(te, tevent_common_timed_destructor);
260 :
261 :
262 417595125 : TEVENT_DEBUG(ev, TEVENT_DEBUG_TRACE,
263 : "Added timed event \"%s\": %p\n",
264 : handler_name, te);
265 406077810 : return te;
266 : }
267 :
268 0 : struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev,
269 : TALLOC_CTX *mem_ctx,
270 : struct timeval next_event,
271 : tevent_timer_handler_t handler,
272 : void *private_data,
273 : const char *handler_name,
274 : const char *location)
275 : {
276 : /*
277 : * do not use optimization, there are broken Samba
278 : * versions which use tevent_common_add_timer()
279 : * without using tevent_common_loop_timer_delay(),
280 : * it just uses DLIST_REMOVE(ev->timer_events, te)
281 : * and would leave ev->last_zero_timer behind.
282 : */
283 0 : return tevent_common_add_timer_internal(ev, mem_ctx, next_event,
284 : handler, private_data,
285 : handler_name, location,
286 : false);
287 : }
288 :
289 417595125 : struct tevent_timer *tevent_common_add_timer_v2(struct tevent_context *ev,
290 : TALLOC_CTX *mem_ctx,
291 : struct timeval next_event,
292 : tevent_timer_handler_t handler,
293 : void *private_data,
294 : const char *handler_name,
295 : const char *location)
296 : {
297 : /*
298 : * Here we turn on last_zero_timer optimization
299 : */
300 417595125 : return tevent_common_add_timer_internal(ev, mem_ctx, next_event,
301 : handler, private_data,
302 : handler_name, location,
303 : true);
304 : }
305 :
306 32839044 : void tevent_update_timer(struct tevent_timer *te, struct timeval next_event)
307 : {
308 32839044 : struct tevent_context *ev = te->event_ctx;
309 :
310 32839044 : if (ev->last_zero_timer == te) {
311 0 : te->event_ctx->last_zero_timer = DLIST_PREV(te);
312 : }
313 32839044 : tevent_trace_timer_callback(te->event_ctx, te, TEVENT_EVENT_TRACE_DETACH);
314 32839044 : DLIST_REMOVE(ev->timer_events, te);
315 :
316 32839044 : te->next_event = next_event;
317 :
318 : /*
319 : * Not doing the zero_timer optimization. This is for new code
320 : * that should know about immediates.
321 : */
322 32839044 : tevent_common_insert_timer(ev, te, false);
323 32839044 : }
324 :
325 205532022 : int tevent_common_invoke_timer_handler(struct tevent_timer *te,
326 : struct timeval current_time,
327 : bool *removed)
328 : {
329 205532022 : struct tevent_context *handler_ev = te->event_ctx;
330 :
331 205532022 : if (removed != NULL) {
332 0 : *removed = false;
333 : }
334 :
335 205532022 : if (te->event_ctx == NULL) {
336 0 : return 0;
337 : }
338 :
339 : /*
340 : * We need to remove the timer from the list before calling the
341 : * handler because in a semi-async inner event loop called from the
342 : * handler we don't want to come across this event again -- vl
343 : */
344 205532022 : if (te->event_ctx->last_zero_timer == te) {
345 203673343 : te->event_ctx->last_zero_timer = DLIST_PREV(te);
346 : }
347 205532022 : DLIST_REMOVE(te->event_ctx->timer_events, te);
348 :
349 205532022 : TEVENT_DEBUG(te->event_ctx, TEVENT_DEBUG_TRACE,
350 : "Running timer event %p \"%s\"\n",
351 : te, te->handler_name);
352 :
353 : /*
354 : * If the timed event was registered for a zero current_time,
355 : * then we pass a zero timeval here too! To avoid the
356 : * overhead of gettimeofday() calls.
357 : *
358 : * otherwise we pass the current time
359 : */
360 205532022 : te->busy = true;
361 205532022 : if (te->wrapper != NULL) {
362 4 : handler_ev = te->wrapper->wrap_ev;
363 :
364 4 : tevent_wrapper_push_use_internal(handler_ev, te->wrapper);
365 4 : te->wrapper->ops->before_timer_handler(
366 0 : te->wrapper->wrap_ev,
367 0 : te->wrapper->private_state,
368 0 : te->wrapper->main_ev,
369 : te,
370 : te->next_event,
371 : current_time,
372 : te->handler_name,
373 : te->location);
374 : }
375 205532022 : tevent_trace_timer_callback(te->event_ctx, te, TEVENT_EVENT_TRACE_BEFORE_HANDLER);
376 205532022 : te->handler(handler_ev, te, current_time, te->private_data);
377 205531947 : if (te->wrapper != NULL) {
378 4 : te->wrapper->ops->after_timer_handler(
379 0 : te->wrapper->wrap_ev,
380 0 : te->wrapper->private_state,
381 0 : te->wrapper->main_ev,
382 : te,
383 : te->next_event,
384 : current_time,
385 : te->handler_name,
386 : te->location);
387 4 : tevent_wrapper_pop_use_internal(handler_ev, te->wrapper);
388 : }
389 205531947 : te->busy = false;
390 :
391 205531947 : TEVENT_DEBUG(te->event_ctx, TEVENT_DEBUG_TRACE,
392 : "Ending timer event %p \"%s\"\n",
393 : te, te->handler_name);
394 :
395 : /* The callback was already called when freed from the handler. */
396 205531947 : if (!te->destroyed) {
397 36890 : tevent_trace_timer_callback(te->event_ctx, te, TEVENT_EVENT_TRACE_DETACH);
398 : }
399 :
400 205531947 : te->wrapper = NULL;
401 205531947 : te->event_ctx = NULL;
402 205531947 : talloc_set_destructor(te, NULL);
403 205531947 : TALLOC_FREE(te);
404 :
405 205531947 : if (removed != NULL) {
406 0 : *removed = true;
407 : }
408 :
409 199832441 : return 0;
410 : }
411 : /*
412 : do a single event loop using the events defined in ev
413 :
414 : return the delay until the next timed event,
415 : or zero if a timed event was triggered
416 : */
417 404707929 : struct timeval tevent_common_loop_timer_delay(struct tevent_context *ev)
418 : {
419 404707929 : struct timeval current_time = tevent_timeval_zero();
420 404707929 : struct tevent_timer *te = ev->timer_events;
421 35108644 : int ret;
422 :
423 404707929 : if (!te) {
424 : /* have a default tick time of 30 seconds. This guarantees
425 : that code that uses its own timeout checking will be
426 : able to proceed eventually */
427 29051015 : return tevent_timeval_set(30, 0);
428 : }
429 :
430 : /*
431 : * work out the right timeout for the next timed event
432 : *
433 : * avoid the syscall to gettimeofday() if the timed event should
434 : * be triggered directly
435 : *
436 : * if there's a delay till the next timed event, we're done
437 : * with just returning the delay
438 : */
439 375656914 : if (!tevent_timeval_is_zero(&te->next_event)) {
440 28991285 : struct timeval delay;
441 :
442 171957240 : current_time = tevent_timeval_current();
443 :
444 171957240 : delay = tevent_timeval_until(¤t_time, &te->next_event);
445 171957240 : if (!tevent_timeval_is_zero(&delay)) {
446 170124892 : return delay;
447 : }
448 : }
449 :
450 : /*
451 : * ok, we have a timed event that we'll process ...
452 : */
453 205532022 : ret = tevent_common_invoke_timer_handler(te, current_time, NULL);
454 205531947 : if (ret != 0) {
455 0 : tevent_abort(ev, "tevent_common_invoke_timer_handler() failed");
456 : }
457 :
458 205531947 : return tevent_timeval_zero();
459 : }
460 :
461 130791 : void tevent_timer_set_tag(struct tevent_timer *te, uint64_t tag)
462 : {
463 130791 : if (te == NULL) {
464 0 : return;
465 : }
466 :
467 130791 : te->tag = tag;
468 : }
469 :
470 5405 : uint64_t tevent_timer_get_tag(const struct tevent_timer *te)
471 : {
472 5405 : if (te == NULL) {
473 0 : return 0;
474 : }
475 :
476 5405 : return te->tag;
477 : }
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