Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2008,2009 by Holger Hans Peter Freyther <zecke@selfish.org> |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 3 | * (C) 2011 by Harald Welte <laforge@gnumonks.org> |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 4 | * All Rights Reserved |
| 5 | * |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 6 | * Authors: Holger Hans Peter Freyther <zecke@selfish.org> |
| 7 | * Harald Welte <laforge@gnumonks.org> |
| 8 | * Pablo Neira Ayuso <pablo@gnumonks.org> |
| 9 | * |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License as published by |
| 12 | * the Free Software Foundation; either version 2 of the License, or |
| 13 | * (at your option) any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License along |
| 21 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 22 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 23 | * |
| 24 | */ |
| 25 | |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 26 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 27 | /*! \addtogroup timer |
| 28 | * @{ |
| 29 | */ |
| 30 | |
| 31 | /*! \file timer.c |
| 32 | */ |
| 33 | |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 34 | #include <assert.h> |
| 35 | #include <string.h> |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 36 | #include <limits.h> |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 37 | #include <osmocom/core/timer.h> |
Sylvain Munaut | 07f1103 | 2011-10-21 21:55:29 +0200 | [diff] [blame] | 38 | #include <osmocom/core/timer_compat.h> |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 39 | #include <osmocom/core/linuxlist.h> |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 40 | |
Holger Hans Peter Freyther | 3f838b7 | 2015-08-20 18:17:15 +0000 | [diff] [blame] | 41 | /* These store the amount of time that we wait until next timer expires. */ |
| 42 | static struct timeval nearest; |
| 43 | static struct timeval *nearest_p; |
| 44 | |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 45 | static struct rb_root timer_root = RB_ROOT; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 46 | |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 47 | static void __add_timer(struct osmo_timer_list *timer) |
| 48 | { |
| 49 | struct rb_node **new = &(timer_root.rb_node); |
| 50 | struct rb_node *parent = NULL; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 51 | |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 52 | while (*new) { |
| 53 | struct osmo_timer_list *this; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 54 | |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 55 | this = container_of(*new, struct osmo_timer_list, node); |
| 56 | |
| 57 | parent = *new; |
| 58 | if (timercmp(&timer->timeout, &this->timeout, <)) |
| 59 | new = &((*new)->rb_left); |
| 60 | else |
| 61 | new = &((*new)->rb_right); |
| 62 | } |
| 63 | |
| 64 | rb_link_node(&timer->node, parent, new); |
| 65 | rb_insert_color(&timer->node, &timer_root); |
| 66 | } |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 67 | |
Pablo Neira Ayuso | 44f423f | 2017-05-08 18:00:28 +0200 | [diff] [blame] | 68 | /*! \brief set up timer callback and data |
| 69 | * \param[in] timer the timer that should be added |
| 70 | * \param[in] callback function to be called when timer expires |
| 71 | * \param[in] pointer to data that passed to the callback function |
| 72 | */ |
| 73 | void osmo_timer_setup(struct osmo_timer_list *timer, void (*cb)(void *data), |
| 74 | void *data) |
| 75 | { |
| 76 | timer->cb = cb; |
| 77 | timer->data = data; |
| 78 | } |
| 79 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 80 | /*! \brief add a new timer to the timer management |
| 81 | * \param[in] timer the timer that should be added |
| 82 | */ |
Pablo Neira Ayuso | 0b21c1c | 2011-05-07 12:42:28 +0200 | [diff] [blame] | 83 | void osmo_timer_add(struct osmo_timer_list *timer) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 84 | { |
Pablo Neira Ayuso | a71b8ea | 2011-11-13 10:11:31 +0100 | [diff] [blame] | 85 | osmo_timer_del(timer); |
| 86 | timer->active = 1; |
| 87 | INIT_LLIST_HEAD(&timer->list); |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 88 | __add_timer(timer); |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 89 | } |
| 90 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 91 | /*! \brief schedule a timer at a given future relative time |
| 92 | * \param[in] timer the to-be-added timer |
| 93 | * \param[in] seconds number of seconds from now |
| 94 | * \param[in] microseconds number of microseconds from now |
| 95 | * |
| 96 | * This function can be used to (re-)schedule a given timer at a |
| 97 | * specified number of seconds+microseconds in the future. It will |
| 98 | * internally add it to the timer management data structures, thus |
| 99 | * osmo_timer_add() is automatically called. |
| 100 | */ |
Pablo Neira Ayuso | 0b21c1c | 2011-05-07 12:42:28 +0200 | [diff] [blame] | 101 | void |
| 102 | osmo_timer_schedule(struct osmo_timer_list *timer, int seconds, int microseconds) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 103 | { |
| 104 | struct timeval current_time; |
| 105 | |
Neels Hofmeyr | 8e2f7e8 | 2016-09-22 03:58:13 +0200 | [diff] [blame] | 106 | osmo_gettimeofday(¤t_time, NULL); |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 107 | timer->timeout.tv_sec = seconds; |
| 108 | timer->timeout.tv_usec = microseconds; |
| 109 | timeradd(&timer->timeout, ¤t_time, &timer->timeout); |
Pablo Neira Ayuso | 0b21c1c | 2011-05-07 12:42:28 +0200 | [diff] [blame] | 110 | osmo_timer_add(timer); |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 111 | } |
| 112 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 113 | /*! \brief delete a timer from timer management |
| 114 | * \param[in] timer the to-be-deleted timer |
| 115 | * |
| 116 | * This function can be used to delete a previously added/scheduled |
| 117 | * timer from the timer management code. |
| 118 | */ |
Pablo Neira Ayuso | 0b21c1c | 2011-05-07 12:42:28 +0200 | [diff] [blame] | 119 | void osmo_timer_del(struct osmo_timer_list *timer) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 120 | { |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 121 | if (timer->active) { |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 122 | timer->active = 0; |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 123 | rb_erase(&timer->node, &timer_root); |
| 124 | /* make sure this is not already scheduled for removal. */ |
| 125 | if (!llist_empty(&timer->list)) |
| 126 | llist_del_init(&timer->list); |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 127 | } |
| 128 | } |
| 129 | |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 130 | /*! \brief check if given timer is still pending |
| 131 | * \param[in] timer the to-be-checked timer |
| 132 | * \return 1 if pending, 0 otherwise |
| 133 | * |
| 134 | * This function can be used to determine whether a given timer |
| 135 | * has alredy expired (returns 0) or is still pending (returns 1) |
| 136 | */ |
Pablo Neira Ayuso | 0b21c1c | 2011-05-07 12:42:28 +0200 | [diff] [blame] | 137 | int osmo_timer_pending(struct osmo_timer_list *timer) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 138 | { |
| 139 | return timer->active; |
| 140 | } |
| 141 | |
Harald Welte | e30b6ac | 2012-07-13 12:21:04 +0200 | [diff] [blame] | 142 | /*! \brief compute the remaining time of a timer |
| 143 | * \param[in] timer the to-be-checked timer |
Katerina Barone-Adesi | c28c6a0 | 2013-02-15 13:27:59 +0100 | [diff] [blame] | 144 | * \param[in] now the current time (NULL if not known) |
Harald Welte | e30b6ac | 2012-07-13 12:21:04 +0200 | [diff] [blame] | 145 | * \param[out] remaining remaining time until timer fires |
| 146 | * \return 0 if timer has not expired yet, -1 if it has |
| 147 | * |
| 148 | * This function can be used to determine the amount of time |
| 149 | * remaining until the expiration of the timer. |
| 150 | */ |
| 151 | int osmo_timer_remaining(const struct osmo_timer_list *timer, |
| 152 | const struct timeval *now, |
| 153 | struct timeval *remaining) |
| 154 | { |
| 155 | struct timeval current_time; |
| 156 | |
Holger Hans Peter Freyther | 8e5435a | 2014-05-23 08:37:02 +0200 | [diff] [blame] | 157 | if (!now) |
Neels Hofmeyr | 8e2f7e8 | 2016-09-22 03:58:13 +0200 | [diff] [blame] | 158 | osmo_gettimeofday(¤t_time, NULL); |
Holger Hans Peter Freyther | 8e5435a | 2014-05-23 08:37:02 +0200 | [diff] [blame] | 159 | else |
| 160 | current_time = *now; |
Harald Welte | e30b6ac | 2012-07-13 12:21:04 +0200 | [diff] [blame] | 161 | |
| 162 | timersub(&timer->timeout, ¤t_time, remaining); |
| 163 | |
| 164 | if (remaining->tv_sec < 0) |
| 165 | return -1; |
| 166 | |
| 167 | return 0; |
| 168 | } |
| 169 | |
Harald Welte | de6e498 | 2012-12-06 21:25:27 +0100 | [diff] [blame] | 170 | /*! \brief Determine time between now and the nearest timer |
| 171 | * \returns pointer to timeval of nearest timer, NULL if there is none |
| 172 | * |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 173 | * if we have a nearest time return the delta between the current |
| 174 | * time and the time of the nearest timer. |
| 175 | * If the nearest timer timed out return NULL and then we will |
| 176 | * dispatch everything after the select |
| 177 | */ |
Harald Welte | 7e82020 | 2011-07-16 10:15:16 +0200 | [diff] [blame] | 178 | struct timeval *osmo_timers_nearest(void) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 179 | { |
Sylvain Munaut | 0061ded | 2011-10-18 20:11:03 +0200 | [diff] [blame] | 180 | /* nearest_p is exactly what we need already: NULL if nothing is |
| 181 | * waiting, {0,0} if we must dispatch immediately, and the correct |
| 182 | * delay if we need to wait */ |
| 183 | return nearest_p; |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 184 | } |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 185 | |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 186 | static void update_nearest(struct timeval *cand, struct timeval *current) |
| 187 | { |
| 188 | if (cand->tv_sec != LONG_MAX) { |
| 189 | if (timercmp(cand, current, >)) |
| 190 | timersub(cand, current, &nearest); |
| 191 | else { |
| 192 | /* loop again inmediately */ |
Harald Welte | 0047602 | 2017-05-15 14:29:13 +0200 | [diff] [blame] | 193 | timerclear(&nearest); |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 194 | } |
| 195 | nearest_p = &nearest; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 196 | } else { |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 197 | nearest_p = NULL; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 198 | } |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 199 | } |
| 200 | |
Harald Welte | de6e498 | 2012-12-06 21:25:27 +0100 | [diff] [blame] | 201 | /*! \brief Find the nearest time and update nearest_p */ |
Harald Welte | 7e82020 | 2011-07-16 10:15:16 +0200 | [diff] [blame] | 202 | void osmo_timers_prepare(void) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 203 | { |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 204 | struct rb_node *node; |
| 205 | struct timeval current; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 206 | |
Neels Hofmeyr | 8e2f7e8 | 2016-09-22 03:58:13 +0200 | [diff] [blame] | 207 | osmo_gettimeofday(¤t, NULL); |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 208 | |
| 209 | node = rb_first(&timer_root); |
| 210 | if (node) { |
| 211 | struct osmo_timer_list *this; |
| 212 | this = container_of(node, struct osmo_timer_list, node); |
| 213 | update_nearest(&this->timeout, ¤t); |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 214 | } else { |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 215 | nearest_p = NULL; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 216 | } |
| 217 | } |
| 218 | |
Harald Welte | de6e498 | 2012-12-06 21:25:27 +0100 | [diff] [blame] | 219 | /*! \brief fire all timers... and remove them */ |
Harald Welte | 7e82020 | 2011-07-16 10:15:16 +0200 | [diff] [blame] | 220 | int osmo_timers_update(void) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 221 | { |
| 222 | struct timeval current_time; |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 223 | struct rb_node *node; |
| 224 | struct llist_head timer_eviction_list; |
| 225 | struct osmo_timer_list *this; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 226 | int work = 0; |
| 227 | |
Neels Hofmeyr | 8e2f7e8 | 2016-09-22 03:58:13 +0200 | [diff] [blame] | 228 | osmo_gettimeofday(¤t_time, NULL); |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 229 | |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 230 | INIT_LLIST_HEAD(&timer_eviction_list); |
| 231 | for (node = rb_first(&timer_root); node; node = rb_next(node)) { |
| 232 | this = container_of(node, struct osmo_timer_list, node); |
| 233 | |
| 234 | if (timercmp(&this->timeout, ¤t_time, >)) |
| 235 | break; |
| 236 | |
| 237 | llist_add(&this->list, &timer_eviction_list); |
| 238 | } |
| 239 | |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 240 | /* |
| 241 | * The callbacks might mess with our list and in this case |
| 242 | * even llist_for_each_entry_safe is not safe to use. To allow |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 243 | * osmo_timer_del to be called from within the callback we need |
| 244 | * to restart the iteration for each element scheduled for removal. |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 245 | * |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 246 | * The problematic scenario is the following: Given two timers A |
| 247 | * and B that have expired at the same time. Thus, they are both |
| 248 | * in the eviction list in this order: A, then B. If we remove |
| 249 | * timer B from the A's callback, we continue with B in the next |
| 250 | * iteration step, leading to an access-after-release. |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 251 | */ |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 252 | restart: |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 253 | llist_for_each_entry(this, &timer_eviction_list, list) { |
| 254 | osmo_timer_del(this); |
Alexander Couzens | ec9bd52 | 2016-11-28 23:22:14 +0100 | [diff] [blame] | 255 | if (this->cb) |
| 256 | this->cb(this->data); |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 257 | work = 1; |
| 258 | goto restart; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 259 | } |
| 260 | |
| 261 | return work; |
| 262 | } |
| 263 | |
Harald Welte | 2d2e2cc | 2016-04-25 12:11:20 +0200 | [diff] [blame] | 264 | /*! \brief Check how many timers we have in the system |
| 265 | * \returns number of \ref osmo_timer_list registered */ |
Pablo Neira Ayuso | 0b21c1c | 2011-05-07 12:42:28 +0200 | [diff] [blame] | 266 | int osmo_timers_check(void) |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 267 | { |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 268 | struct rb_node *node; |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 269 | int i = 0; |
| 270 | |
Pablo Neira Ayuso | 066c912 | 2011-09-26 11:45:03 +0200 | [diff] [blame] | 271 | for (node = rb_first(&timer_root); node; node = rb_next(node)) { |
Harald Welte | ec8b450 | 2010-02-20 20:34:29 +0100 | [diff] [blame] | 272 | i++; |
| 273 | } |
| 274 | return i; |
| 275 | } |
Harald Welte | ba6988b | 2011-08-17 12:46:48 +0200 | [diff] [blame] | 276 | |
Sylvain Munaut | dca7d2c | 2012-04-18 21:53:23 +0200 | [diff] [blame] | 277 | /*! @} */ |