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/>.
26 #include "system/filesys.h"
27 #include "system/select.h"
29 #include "tevent_internal.h"
30 #include "tevent_util.h"
33 compare two timeval structures.
34 Return -1 if tv1 < tv2
35 Return 0 if tv1 == tv2
38 static int ev_timeval_compare(const struct timeval *tv1, const struct timeval *tv2)
40 if (tv1->tv_sec > tv2->tv_sec) return 1;
41 if (tv1->tv_sec < tv2->tv_sec) return -1;
42 if (tv1->tv_usec > tv2->tv_usec) return 1;
43 if (tv1->tv_usec < tv2->tv_usec) return -1;
50 static struct timeval ev_timeval_zero(void)
59 return a timeval for the current time
61 static struct timeval ev_timeval_current(void)
64 gettimeofday(&tv, NULL);
69 return a timeval struct with the given elements
71 static struct timeval ev_timeval_set(uint32_t secs, uint32_t usecs)
80 return the difference between two timevals as a timeval
81 if tv1 comes after tv2, then return a zero timeval
84 static struct timeval ev_timeval_until(const struct timeval *tv1,
85 const struct timeval *tv2)
88 if (ev_timeval_compare(tv1, tv2) >= 0) {
89 return ev_timeval_zero();
91 t.tv_sec = tv2->tv_sec - tv1->tv_sec;
92 if (tv1->tv_usec > tv2->tv_usec) {
94 t.tv_usec = 1000000 - (tv1->tv_usec - tv2->tv_usec);
96 t.tv_usec = tv2->tv_usec - tv1->tv_usec;
102 return true if a timeval is zero
104 bool ev_timeval_is_zero(const struct timeval *tv)
106 return tv->tv_sec == 0 && tv->tv_usec == 0;
110 destroy a timed event
112 static int common_event_timed_destructor(struct tevent_timer *te)
114 struct tevent_context *ev = talloc_get_type(te->event_ctx,
115 struct tevent_context);
116 DLIST_REMOVE(ev->timer_events, te);
120 static int common_event_timed_deny_destructor(struct tevent_timer *te)
127 return NULL on failure (memory allocation error)
129 struct tevent_timer *common_event_add_timed(struct tevent_context *ev, TALLOC_CTX *mem_ctx,
130 struct timeval next_event,
131 event_timed_handler_t handler,
134 struct tevent_timer *te, *last_te, *cur_te;
136 te = talloc(mem_ctx?mem_ctx:ev, struct tevent_timer);
137 if (te == NULL) return NULL;
140 te->next_event = next_event;
141 te->handler = handler;
142 te->private_data = private_data;
143 te->additional_data = NULL;
145 /* keep the list ordered */
147 for (cur_te = ev->timer_events; cur_te; cur_te = cur_te->next) {
148 /* if the new event comes before the current one break */
149 if (ev_timeval_compare(&te->next_event, &cur_te->next_event) < 0) {
156 DLIST_ADD_AFTER(ev->timer_events, te, last_te);
158 talloc_set_destructor(te, common_event_timed_destructor);
164 do a single event loop using the events defined in ev
166 return the delay untill the next timed event,
167 or zero if a timed event was triggered
169 struct timeval common_event_loop_timer_delay(struct tevent_context *ev)
171 struct timeval current_time = ev_timeval_zero();
172 struct tevent_timer *te = ev->timer_events;
175 /* have a default tick time of 30 seconds. This guarantees
176 that code that uses its own timeout checking will be
177 able to proceeed eventually */
178 return ev_timeval_set(30, 0);
182 * work out the right timeout for the next timed event
184 * avoid the syscall to gettimeofday() if the timed event should
185 * be triggered directly
187 * if there's a delay till the next timed event, we're done
188 * with just returning the delay
190 if (!ev_timeval_is_zero(&te->next_event)) {
191 struct timeval delay;
193 current_time = ev_timeval_current();
195 delay = ev_timeval_until(¤t_time, &te->next_event);
196 if (!ev_timeval_is_zero(&delay)) {
202 * ok, we have a timed event that we'll process ...
205 /* deny the handler to free the event */
206 talloc_set_destructor(te, common_event_timed_deny_destructor);
208 /* We need to remove the timer from the list before calling the
209 * handler because in a semi-async inner event loop called from the
210 * handler we don't want to come across this event again -- vl */
211 DLIST_REMOVE(ev->timer_events, te);
214 * If the timed event was registered for a zero current_time,
215 * then we pass a zero timeval here too! To avoid the
216 * overhead of gettimeofday() calls.
218 * otherwise we pass the current time
220 te->handler(ev, te, current_time, te->private_data);
222 /* The destructor isn't necessary anymore, we've already removed the
223 * event from the list. */
224 talloc_set_destructor(te, NULL);
228 return ev_timeval_zero();