2 Unix SMB/CIFS implementation.
4 common events code for timed events
6 Copyright (C) Andrew Tridgell 2003-2006
7 Copyright (C) Stefan Metzmacher 2005
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>.
24 #include "system/time.h"
26 #include "tevent_internal.h"
27 #include "tevent_util.h"
30 compare two timeval structures.
31 Return -1 if tv1 < tv2
32 Return 0 if tv1 == tv2
35 static int ev_timeval_compare(const struct timeval *tv1, const struct timeval *tv2)
37 if (tv1->tv_sec > tv2->tv_sec) return 1;
38 if (tv1->tv_sec < tv2->tv_sec) return -1;
39 if (tv1->tv_usec > tv2->tv_usec) return 1;
40 if (tv1->tv_usec < tv2->tv_usec) return -1;
47 struct timeval ev_timeval_zero(void)
56 return a timeval for the current time
58 static struct timeval ev_timeval_current(void)
61 gettimeofday(&tv, NULL);
66 return a timeval struct with the given elements
68 static struct timeval ev_timeval_set(uint32_t secs, uint32_t usecs)
77 return the difference between two timevals as a timeval
78 if tv1 comes after tv2, then return a zero timeval
81 static struct timeval ev_timeval_until(const struct timeval *tv1,
82 const struct timeval *tv2)
85 if (ev_timeval_compare(tv1, tv2) >= 0) {
86 return ev_timeval_zero();
88 t.tv_sec = tv2->tv_sec - tv1->tv_sec;
89 if (tv1->tv_usec > tv2->tv_usec) {
91 t.tv_usec = 1000000 - (tv1->tv_usec - tv2->tv_usec);
93 t.tv_usec = tv2->tv_usec - tv1->tv_usec;
99 return true if a timeval is zero
101 bool ev_timeval_is_zero(const struct timeval *tv)
103 return tv->tv_sec == 0 && tv->tv_usec == 0;
107 destroy a timed event
109 static int tevent_common_timed_destructor(struct tevent_timer *te)
111 tevent_debug(te->event_ctx, TEVENT_DEBUG_TRACE,
112 "Destroying timer event %p \"%s\"\n",
113 te, te->handler_name);
116 DLIST_REMOVE(te->event_ctx->timer_events, te);
122 static int tevent_common_timed_deny_destructor(struct tevent_timer *te)
129 return NULL on failure (memory allocation error)
131 struct tevent_timer *tevent_common_add_timer(struct tevent_context *ev, TALLOC_CTX *mem_ctx,
132 struct timeval next_event,
133 tevent_timer_handler_t handler,
135 const char *handler_name,
136 const char *location)
138 struct tevent_timer *te, *last_te, *cur_te;
140 te = talloc(mem_ctx?mem_ctx:ev, struct tevent_timer);
141 if (te == NULL) return NULL;
144 te->next_event = next_event;
145 te->handler = handler;
146 te->private_data = private_data;
147 te->handler_name = handler_name;
148 te->location = location;
149 te->additional_data = NULL;
151 /* keep the list ordered */
153 for (cur_te = ev->timer_events; cur_te; cur_te = cur_te->next) {
154 /* if the new event comes before the current one break */
155 if (ev_timeval_compare(&te->next_event, &cur_te->next_event) < 0) {
162 DLIST_ADD_AFTER(ev->timer_events, te, last_te);
164 talloc_set_destructor(te, tevent_common_timed_destructor);
166 tevent_debug(ev, TEVENT_DEBUG_TRACE,
167 "Added timed event \"%s\": %p\n",
173 do a single event loop using the events defined in ev
175 return the delay untill the next timed event,
176 or zero if a timed event was triggered
178 struct timeval tevent_common_loop_timer_delay(struct tevent_context *ev)
180 struct timeval current_time = ev_timeval_zero();
181 struct tevent_timer *te = ev->timer_events;
184 /* have a default tick time of 30 seconds. This guarantees
185 that code that uses its own timeout checking will be
186 able to proceeed eventually */
187 return ev_timeval_set(30, 0);
191 * work out the right timeout for the next timed event
193 * avoid the syscall to gettimeofday() if the timed event should
194 * be triggered directly
196 * if there's a delay till the next timed event, we're done
197 * with just returning the delay
199 if (!ev_timeval_is_zero(&te->next_event)) {
200 struct timeval delay;
202 current_time = ev_timeval_current();
204 delay = ev_timeval_until(¤t_time, &te->next_event);
205 if (!ev_timeval_is_zero(&delay)) {
211 * ok, we have a timed event that we'll process ...
214 /* deny the handler to free the event */
215 talloc_set_destructor(te, tevent_common_timed_deny_destructor);
217 /* We need to remove the timer from the list before calling the
218 * handler because in a semi-async inner event loop called from the
219 * handler we don't want to come across this event again -- vl */
220 DLIST_REMOVE(ev->timer_events, te);
223 * If the timed event was registered for a zero current_time,
224 * then we pass a zero timeval here too! To avoid the
225 * overhead of gettimeofday() calls.
227 * otherwise we pass the current time
229 te->handler(ev, te, current_time, te->private_data);
231 /* The destructor isn't necessary anymore, we've already removed the
232 * event from the list. */
233 talloc_set_destructor(te, NULL);
235 tevent_debug(te->event_ctx, TEVENT_DEBUG_TRACE,
236 "Ending timer event %p \"%s\"\n",
237 te, te->handler_name);
241 return ev_timeval_zero();