Dogcows Code - chaz/tint2/blob - src/util/timer.c

   1 /**************************************************************************
   2 *
   3 * Copyright (C) 2009 Andreas.Fink (Andreas.Fink85@gmail.com)
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License version 2
   7 * as published by the Free Software Foundation.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program; if not, write to the Free Software
  15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  16 **************************************************************************/
  17
  18 #include <time.h>
  19 #include <stdlib.h>
  20 #include <stdio.h>
  21
  22 #include "timer.h"
  23
  24 GSList* timeout_list = 0;
  25 struct timeval next_timeout;
  26
  27
  28 // functions and structs for multi timeouts
  29 typedef struct {
  30         int current_count;
  31         int count_to_expiration;
  32 } multi_timeout;
  33
  34 typedef struct {
  35         GSList* timeout_list;
  36         timeout* parent_timeout;
  37 } multi_timeout_handler;
  38
  39 struct _timeout {
  40         int interval_msec;
  41         struct timespec timeout_expires;
  42         void (*_callback)(void*);
  43         void* arg;
  44         multi_timeout* multi_timeout;
  45 };
  46
  47 void add_timeout_intern(int value_msec, int interval_msec, void(*_callback)(void*), void* arg, timeout* t);
  48 gint compare_timeouts(gconstpointer t1, gconstpointer t2);
  49 gint compare_timespecs(const struct timespec* t1, const struct timespec* t2);
  50 int timespec_subtract(struct timespec* result, struct timespec* x, struct timespec* y);
  51 struct timespec add_msec_to_timespec(struct timespec ts, int msec);
  52
  53
  54 int align_with_existing_timeouts(timeout* t);
  55 void create_multi_timeout(timeout* t1, timeout* t2);
  56 void append_multi_timeout(timeout* t1, timeout* t2);
  57 int calc_multi_timeout_interval(multi_timeout_handler* mth);
  58 void update_multi_timeout_values(multi_timeout_handler* mth);
  59 void callback_multi_timeout(void* mth);
  60 void remove_from_multi_timeout(timeout* t);
  61 void stop_multi_timeout(timeout* t);
  62
  63 GHashTable* multi_timeouts = 0;
  64
  65 /** Implementation notes for timeouts: The timeouts are kept in a GSList sorted by their
  66         * expiration time.
  67         * That means that update_next_timeout() only have to consider the first timeout in the list,
  68         * and callback_timeout_expired() only have to consider the timeouts as long as the expiration time
  69         * is in the past to the current time.
  70         * As time measurement we use clock_gettime(CLOCK_MONOTONIC) because this refers to a timer, which
  71         * reference point lies somewhere in the past and cannot be changed, but just queried.
  72         * If a single shot timer is installed it will be automatically deleted. I.e. the returned value
  73         * of add_timeout will not be valid anymore. You do not need to call stop_timeout for these timeouts,
  74         * however it's save to call it.
  75 **/
  76
  77 timeout* add_timeout(int value_msec, int interval_msec, void (*_callback)(void*), void* arg)
  78 {
  79         timeout* t = malloc(sizeof(timeout));
  80         t->multi_timeout = 0;
  81         add_timeout_intern(value_msec, interval_msec, _callback, arg, t);
  82         return t;
  83 }
  84
  85
  86 void change_timeout(timeout *t, int value_msec, int interval_msec, void(*_callback)(), void* arg)
  87 {
  88         if ( g_slist_find(timeout_list, t) == 0 && g_hash_table_lookup(multi_timeouts, t) == 0)
  89                 printf("programming error: timeout already deleted...");
  90         else {
  91                 if (t->multi_timeout)
  92                         remove_from_multi_timeout((timeout*)t);
  93                 else
  94                         timeout_list = g_slist_remove(timeout_list, t);
  95                 add_timeout_intern(value_msec, interval_msec, _callback, arg, (timeout*)t);
  96         }
  97 }
  98
  99
 100 void update_next_timeout()
 101 {
 102         if (timeout_list) {
 103                 timeout* t = timeout_list->data;
 104                 struct timespec cur_time;
 105                 struct timespec next_timeout2 = { .tv_sec=next_timeout.tv_sec, .tv_nsec=next_timeout.tv_usec*1000 };
 106                 clock_gettime(CLOCK_MONOTONIC, &cur_time);
 107                 if (timespec_subtract(&next_timeout2, &t->timeout_expires, &cur_time)) {
 108                         next_timeout.tv_sec = 0;
 109                         next_timeout.tv_usec = 0;
 110                 }
 111                 else {
 112                         next_timeout.tv_sec = next_timeout2.tv_sec;
 113                         next_timeout.tv_usec = next_timeout2.tv_nsec/1000;
 114                 }
 115         }
 116         else
 117                 next_timeout.tv_sec = -1;
 118 }
 119
 120
 121 void callback_timeout_expired()
 122 {
 123         struct timespec cur_time;
 124         timeout* t;
 125         while (timeout_list) {
 126                 clock_gettime(CLOCK_MONOTONIC, &cur_time);
 127                 t = timeout_list->data;
 128                 if (compare_timespecs(&t->timeout_expires, &cur_time) <= 0) {
 129                         // it's time for the callback function
 130                         t->_callback(t->arg);
 131                         if (g_slist_find(timeout_list, t)) {
 132                                 // if _callback() calls stop_timeout(t) the timeout 't' was freed and is not in the timeout_list
 133                                 timeout_list = g_slist_remove(timeout_list, t);
 134                                 if (t->interval_msec > 0)
 135                                         add_timeout_intern(t->interval_msec, t->interval_msec, t->_callback, t->arg, t);
 136                                 else
 137                                         free(t);
 138                         }
 139                 }
 140                 else
 141                         return;
 142         }
 143 }
 144
 145
 146 void stop_timeout(timeout* t)
 147 {
 148         // if not in the list, it was deleted in callback_timeout_expired
 149         if (g_slist_find(timeout_list, t) || g_hash_table_lookup(multi_timeouts, t)) {
 150                 if (t->multi_timeout)
 151                         remove_from_multi_timeout((timeout*)t);
 152                 timeout_list = g_slist_remove(timeout_list, t);
 153                 free((void*)t);
 154         }
 155 }
 156
 157
 158 void stop_all_timeouts()
 159 {
 160         while (timeout_list) {
 161                 timeout* t = timeout_list->data;
 162                 if (t->multi_timeout)
 163                         stop_multi_timeout(t);
 164                 free(t);
 165                 timeout_list = g_slist_remove(timeout_list, t);
 166         }
 167 }
 168
 169
 170 void add_timeout_intern(int value_msec, int interval_msec, void(*_callback)(), void* arg, timeout *t)
 171 {
 172         t->interval_msec = interval_msec;
 173         t->_callback = _callback;
 174         t->arg = arg;
 175         struct timespec cur_time;
 176         clock_gettime(CLOCK_MONOTONIC, &cur_time);
 177         t->timeout_expires = add_msec_to_timespec(cur_time, value_msec);
 178
 179         int can_align = 0;
 180         if (interval_msec > 0 && !t->multi_timeout)
 181                 can_align = align_with_existing_timeouts(t);
 182         if (!can_align)
 183                 timeout_list = g_slist_insert_sorted(timeout_list, t, compare_timeouts);
 184 }
 185
 186
 187 gint compare_timeouts(gconstpointer t1, gconstpointer t2)
 188 {
 189         return compare_timespecs(&((timeout*)t1)->timeout_expires,
 190                                                                                                          &((timeout*)t2)->timeout_expires);
 191 }
 192
 193
 194 gint compare_timespecs(const struct timespec* t1, const struct timespec* t2)
 195 {
 196         if (t1->tv_sec < t2->tv_sec)
 197                 return -1;
 198         else if (t1->tv_sec == t2->tv_sec) {
 199                 if (t1->tv_nsec < t2->tv_nsec)
 200                         return -1;
 201                 else if (t1->tv_nsec == t2->tv_nsec)
 202                         return 0;
 203                 else
 204                         return 1;
 205         }
 206         else
 207                 return 1;
 208 }
 209
 210 int timespec_subtract(struct timespec* result, struct timespec* x, struct timespec* y)
 211 {
 212         /* Perform the carry for the later subtraction by updating y. */
 213         if (x->tv_nsec < y->tv_nsec) {
 214                 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
 215                 y->tv_nsec -= 1000000000 * nsec;
 216                 y->tv_sec += nsec;
 217         }
 218         if (x->tv_nsec - y->tv_nsec > 1000000000) {
 219                 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
 220                 y->tv_nsec += 1000000000 * nsec;
 221                 y->tv_sec -= nsec;
 222         }
 223
 224         /* Compute the time remaining to wait. tv_nsec is certainly positive. */
 225         result->tv_sec = x->tv_sec - y->tv_sec;
 226         result->tv_nsec = x->tv_nsec - y->tv_nsec;
 227
 228         /* Return 1 if result is negative. */
 229         return x->tv_sec < y->tv_sec;
 230 }
 231
 232
 233 struct timespec add_msec_to_timespec(struct timespec ts, int msec)
 234 {
 235         ts.tv_sec += msec / 1000;
 236         ts.tv_nsec += (msec % 1000)*1000000;
 237         if (ts.tv_nsec >= 1000000000) {  // 10^9
 238                 ts.tv_sec++;
 239                 ts.tv_nsec -= 1000000000;
 240         }
 241         return ts;
 242 }
 243
 244
 245 int align_with_existing_timeouts(timeout *t)
 246 {
 247         GSList* it = timeout_list;
 248         while (it) {
 249                 timeout* t2 = it->data;
 250                 if (t2->interval_msec > 0) {
 251                         if (t->interval_msec % t2->interval_msec == 0 || t2->interval_msec % t->interval_msec == 0) {
 252                                 if (multi_timeouts == 0)
 253                                         multi_timeouts = g_hash_table_new(0, 0);
 254                                 if (!t->multi_timeout && !t2->multi_timeout)
 255                                         // both timeouts can be aligned, but there is no multi timeout for them
 256                                         create_multi_timeout(t, t2);
 257                                 else
 258                                         // there is already a multi timeout, so we append the new timeout to the multi timeout
 259                                         append_multi_timeout(t, t2);
 260                                 return 1;
 261                         }
 262                 }
 263                 it = it->next;
 264         }
 265         return 0;
 266 }
 267
 268
 269 int calc_multi_timeout_interval(multi_timeout_handler* mth)
 270 {
 271         GSList* it = mth->timeout_list;
 272         timeout* t = it->data;
 273         int min_interval = t->interval_msec;
 274         it = it->next;
 275         while (it) {
 276                 t = it->data;
 277                 if (t->interval_msec < min_interval)
 278                         min_interval = t->interval_msec;
 279                 it = it->next;
 280         }
 281         return min_interval;
 282 }
 283
 284
 285 void create_multi_timeout(timeout* t1, timeout* t2)
 286 {
 287         multi_timeout* mt1 = malloc(sizeof(multi_timeout));
 288         multi_timeout* mt2 = malloc(sizeof(multi_timeout));
 289         multi_timeout_handler* mth = malloc(sizeof(multi_timeout_handler));
 290         timeout* real_timeout = malloc(sizeof(timeout));
 291
 292         mth->timeout_list = 0;
 293         mth->timeout_list = g_slist_prepend(mth->timeout_list, t1);
 294         mth->timeout_list = g_slist_prepend(mth->timeout_list, t2);
 295         mth->parent_timeout = real_timeout;
 296
 297         g_hash_table_insert(multi_timeouts, t1, mth);
 298         g_hash_table_insert(multi_timeouts, t2, mth);
 299         g_hash_table_insert(multi_timeouts, real_timeout, mth);
 300
 301         t1->multi_timeout = mt1;
 302         t2->multi_timeout = mt2;
 303         // set real_timeout->multi_timeout to something, such that we see in add_timeout_intern that
 304         // it is already a multi_timeout (we never use it, except of checking for 0 ptr)
 305         real_timeout->multi_timeout = (void*)real_timeout;
 306
 307         timeout_list = g_slist_remove(timeout_list, t1);
 308         timeout_list = g_slist_remove(timeout_list, t2);
 309
 310         update_multi_timeout_values(mth);
 311 }
 312
 313
 314 void append_multi_timeout(timeout* t1, timeout* t2)
 315 {
 316         if (t2->multi_timeout) {
 317                 // swap t1 and t2 such that t1 is the multi timeout
 318                 timeout* tmp = t2;
 319                 t2 = t1;
 320                 t1 = tmp;
 321         }
 322
 323         multi_timeout* mt = malloc(sizeof(multi_timeout));
 324         multi_timeout_handler* mth = g_hash_table_lookup(multi_timeouts, t1);
 325
 326         mth->timeout_list = g_slist_prepend(mth->timeout_list, t2);
 327         g_hash_table_insert(multi_timeouts, t2, mth);
 328
 329         t2->multi_timeout = mt;
 330
 331         update_multi_timeout_values(mth);
 332 }
 333
 334
 335 void update_multi_timeout_values(multi_timeout_handler* mth)
 336 {
 337         int interval = calc_multi_timeout_interval(mth);
 338         int next_timeout_msec = interval;
 339
 340         struct timespec cur_time;
 341         clock_gettime(CLOCK_MONOTONIC, &cur_time);
 342
 343         GSList* it = mth->timeout_list;
 344         struct timespec diff_time;
 345         while (it) {
 346                 timeout* t = it->data;
 347                 t->multi_timeout->count_to_expiration = t->interval_msec / interval;
 348                 timespec_subtract(&diff_time, &t->timeout_expires, &cur_time);
 349                 int msec_to_expiration = diff_time.tv_sec*1000 + diff_time.tv_nsec/1000000;
 350                 int count_left = msec_to_expiration / interval + (msec_to_expiration%interval != 0);
 351                 t->multi_timeout->current_count = t->multi_timeout->count_to_expiration - count_left;
 352                 if (msec_to_expiration < next_timeout_msec)
 353                         next_timeout_msec = msec_to_expiration;
 354                 it = it->next;
 355         }
 356
 357         mth->parent_timeout->interval_msec = interval;
 358         timeout_list = g_slist_remove(timeout_list, mth->parent_timeout);
 359         add_timeout_intern(next_timeout_msec, interval, callback_multi_timeout, mth, mth->parent_timeout);
 360 }
 361
 362
 363 void callback_multi_timeout(void* arg)
 364 {
 365         multi_timeout_handler* mth = arg;
 366         struct timespec cur_time;
 367         clock_gettime(CLOCK_MONOTONIC, &cur_time);
 368         GSList* it = mth->timeout_list;
 369         while (it) {
 370                 timeout* t = it->data;
 371                 if (++t->multi_timeout->current_count >= t->multi_timeout->count_to_expiration) {
 372                         t->_callback(t->arg);
 373                         t->multi_timeout->current_count = 0;
 374                         t->timeout_expires = add_msec_to_timespec(cur_time, t->interval_msec);
 375                 }
 376                 it = it->next;
 377         }
 378 }
 379
 380
 381 void remove_from_multi_timeout(timeout* t)
 382 {
 383         multi_timeout_handler* mth = g_hash_table_lookup(multi_timeouts, t);
 384         g_hash_table_remove(multi_timeouts, t);
 385
 386         mth->timeout_list = g_slist_remove(mth->timeout_list, t);
 387         free(t->multi_timeout);
 388         t->multi_timeout = 0;
 389
 390         if (g_slist_length(mth->timeout_list) == 1) {
 391                 timeout* last_timeout = mth->timeout_list->data;
 392                 free(last_timeout->multi_timeout);
 393                 last_timeout->multi_timeout = 0;
 394                 g_hash_table_remove(multi_timeouts, last_timeout);
 395                 g_hash_table_remove(multi_timeouts, mth->parent_timeout);
 396                 mth->parent_timeout->multi_timeout = 0;
 397                 stop_timeout(mth->parent_timeout);
 398                 free(mth);
 399
 400                 struct timespec cur_time, diff_time;
 401                 clock_gettime(CLOCK_MONOTONIC, &cur_time);
 402                 timespec_subtract(&diff_time, &t->timeout_expires, &cur_time);
 403                 int msec_to_expiration = diff_time.tv_sec*1000 + diff_time.tv_nsec/1000000;
 404                 add_timeout_intern(msec_to_expiration, last_timeout->interval_msec, last_timeout->_callback, last_timeout->arg, last_timeout);
 405         }
 406         else
 407                 update_multi_timeout_values(mth);
 408 }
 409
 410
 411 void stop_multi_timeout(timeout* t)
 412 {
 413         multi_timeout_handler* mth = g_hash_table_lookup(multi_timeouts, t);
 414         g_hash_table_remove(multi_timeouts, mth->parent_timeout);
 415         while (mth->timeout_list) {
 416                 timeout* t1 = mth->timeout_list->data;
 417                 mth->timeout_list = g_slist_remove(mth->timeout_list, t1);
 418                 g_hash_table_remove(multi_timeouts, t1);
 419                 free(t1->multi_timeout);
 420                 free(t1);
 421         }
 422         free(mth);
 423 }