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 <sys/time.h>
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22
  23 #include "timer.h"
  24
  25 GSList* timeout_list;
  26 struct timeval next_timeout;
  27 GHashTable* multi_timeouts;
  28
  29
  30 // functions and structs for multi timeouts
  31 typedef struct {
  32         int current_count;
  33         int count_to_expiration;
  34 } multi_timeout;
  35
  36 typedef struct {
  37         GSList* timeout_list;
  38         timeout* parent_timeout;
  39 } multi_timeout_handler;
  40
  41 struct _timeout {
  42         int interval_msec;
  43         struct timespec timeout_expires;
  44         void (*_callback)(void*);
  45         void* arg;
  46         multi_timeout* multi_timeout;
  47 };
  48
  49
  50 void default_timeout()
  51 {
  52         timeout_list = 0;
  53         multi_timeouts = 0;
  54 }
  55
  56 void cleanup_timeout()
  57 {
  58         while (timeout_list) {
  59                 timeout* t = timeout_list->data;
  60                 if (t->multi_timeout)
  61                         stop_multi_timeout(t);
  62                 free(t);
  63                 timeout_list = g_slist_remove(timeout_list, t);
  64         }
  65 }
  66
  67 void add_timeout_intern(int value_msec, int interval_msec, void(*_callback)(void*), void* arg, timeout* t);
  68 gint compare_timeouts(gconstpointer t1, gconstpointer t2);
  69 gint compare_timespecs(const struct timespec* t1, const struct timespec* t2);
  70 int timespec_subtract(struct timespec* result, struct timespec* x, struct timespec* y);
  71 struct timespec add_msec_to_timespec(struct timespec ts, int msec);
  72
  73
  74 int align_with_existing_timeouts(timeout* t);
  75 void create_multi_timeout(timeout* t1, timeout* t2);
  76 void append_multi_timeout(timeout* t1, timeout* t2);
  77 int calc_multi_timeout_interval(multi_timeout_handler* mth);
  78 void update_multi_timeout_values(multi_timeout_handler* mth);
  79 void callback_multi_timeout(void* mth);
  80 void remove_from_multi_timeout(timeout* t);
  81 void stop_multi_timeout(timeout* t);
  82
  83 /** Implementation notes for timeouts: The timeouts are kept in a GSList sorted by their
  84         * expiration time.
  85         * That means that update_next_timeout() only have to consider the first timeout in the list,
  86         * and callback_timeout_expired() only have to consider the timeouts as long as the expiration time
  87         * is in the past to the current time.
  88         * As time measurement we use clock_gettime(CLOCK_MONOTONIC) because this refers to a timer, which
  89         * reference point lies somewhere in the past and cannot be changed, but just queried.
  90         * If a single shot timer is installed it will be automatically deleted. I.e. the returned value
  91         * of add_timeout will not be valid anymore. You do not need to call stop_timeout for these timeouts,
  92         * however it's save to call it.
  93 **/
  94
  95 timeout* add_timeout(int value_msec, int interval_msec, void (*_callback)(void*), void* arg)
  96 {
  97         timeout* t = malloc(sizeof(timeout));
  98         t->multi_timeout = 0;
  99         add_timeout_intern(value_msec, interval_msec, _callback, arg, t);
 100         return t;
 101 }
 102
 103
 104 void change_timeout(timeout *t, int value_msec, int interval_msec, void(*_callback)(), void* arg)
 105 {
 106         if ( g_slist_find(timeout_list, t) == 0 && g_hash_table_lookup(multi_timeouts, t) == 0)
 107                 printf("programming error: timeout already deleted...");
 108         else {
 109                 if (t->multi_timeout)
 110                         remove_from_multi_timeout((timeout*)t);
 111                 else
 112                         timeout_list = g_slist_remove(timeout_list, t);
 113                 add_timeout_intern(value_msec, interval_msec, _callback, arg, (timeout*)t);
 114         }
 115 }
 116
 117
 118 void update_next_timeout()
 119 {
 120         if (timeout_list) {
 121                 timeout* t = timeout_list->data;
 122                 struct timespec cur_time;
 123                 struct timespec next_timeout2 = { .tv_sec=next_timeout.tv_sec, .tv_nsec=next_timeout.tv_usec*1000 };
 124                 clock_gettime(CLOCK_MONOTONIC, &cur_time);
 125                 if (timespec_subtract(&next_timeout2, &t->timeout_expires, &cur_time)) {
 126                         next_timeout.tv_sec = 0;
 127                         next_timeout.tv_usec = 0;
 128                 }
 129                 else {
 130                         next_timeout.tv_sec = next_timeout2.tv_sec;
 131                         next_timeout.tv_usec = next_timeout2.tv_nsec/1000;
 132                 }
 133         }
 134         else
 135                 next_timeout.tv_sec = -1;
 136 }
 137
 138
 139 void callback_timeout_expired()
 140 {
 141         struct timespec cur_time;
 142         timeout* t;
 143         while (timeout_list) {
 144                 clock_gettime(CLOCK_MONOTONIC, &cur_time);
 145                 t = timeout_list->data;
 146                 if (compare_timespecs(&t->timeout_expires, &cur_time) <= 0) {
 147                         // it's time for the callback function
 148                         t->_callback(t->arg);
 149                         if (g_slist_find(timeout_list, t)) {
 150                                 // if _callback() calls stop_timeout(t) the timeout 't' was freed and is not in the timeout_list
 151                                 timeout_list = g_slist_remove(timeout_list, t);
 152                                 if (t->interval_msec > 0)
 153                                         add_timeout_intern(t->interval_msec, t->interval_msec, t->_callback, t->arg, t);
 154                                 else
 155                                         free(t);
 156                         }
 157                 }
 158                 else
 159                         return;
 160         }
 161 }
 162
 163
 164 void stop_timeout(timeout* t)
 165 {
 166         // if not in the list, it was deleted in callback_timeout_expired
 167         if (g_slist_find(timeout_list, t) || g_hash_table_lookup(multi_timeouts, t)) {
 168                 if (t->multi_timeout)
 169                         remove_from_multi_timeout((timeout*)t);
 170                 timeout_list = g_slist_remove(timeout_list, t);
 171                 free((void*)t);
 172         }
 173 }
 174
 175
 176 void add_timeout_intern(int value_msec, int interval_msec, void(*_callback)(), void* arg, timeout *t)
 177 {
 178         t->interval_msec = interval_msec;
 179         t->_callback = _callback;
 180         t->arg = arg;
 181         struct timespec cur_time;
 182         clock_gettime(CLOCK_MONOTONIC, &cur_time);
 183         t->timeout_expires = add_msec_to_timespec(cur_time, value_msec);
 184
 185         int can_align = 0;
 186         if (interval_msec > 0 && !t->multi_timeout)
 187                 can_align = align_with_existing_timeouts(t);
 188         if (!can_align)
 189                 timeout_list = g_slist_insert_sorted(timeout_list, t, compare_timeouts);
 190 }
 191
 192
 193 gint compare_timeouts(gconstpointer t1, gconstpointer t2)
 194 {
 195         return compare_timespecs(&((timeout*)t1)->timeout_expires,
 196                                                                                                          &((timeout*)t2)->timeout_expires);
 197 }
 198
 199
 200 gint compare_timespecs(const struct timespec* t1, const struct timespec* t2)
 201 {
 202         if (t1->tv_sec < t2->tv_sec)
 203                 return -1;
 204         else if (t1->tv_sec == t2->tv_sec) {
 205                 if (t1->tv_nsec < t2->tv_nsec)
 206                         return -1;
 207                 else if (t1->tv_nsec == t2->tv_nsec)
 208                         return 0;
 209                 else
 210                         return 1;
 211         }
 212         else
 213                 return 1;
 214 }
 215
 216 int timespec_subtract(struct timespec* result, struct timespec* x, struct timespec* y)
 217 {
 218         /* Perform the carry for the later subtraction by updating y. */
 219         if (x->tv_nsec < y->tv_nsec) {
 220                 int nsec = (y->tv_nsec - x->tv_nsec) / 1000000000 + 1;
 221                 y->tv_nsec -= 1000000000 * nsec;
 222                 y->tv_sec += nsec;
 223         }
 224         if (x->tv_nsec - y->tv_nsec > 1000000000) {
 225                 int nsec = (x->tv_nsec - y->tv_nsec) / 1000000000;
 226                 y->tv_nsec += 1000000000 * nsec;
 227                 y->tv_sec -= nsec;
 228         }
 229
 230         /* Compute the time remaining to wait. tv_nsec is certainly positive. */
 231         result->tv_sec = x->tv_sec - y->tv_sec;
 232         result->tv_nsec = x->tv_nsec - y->tv_nsec;
 233
 234         /* Return 1 if result is negative. */
 235         return x->tv_sec < y->tv_sec;
 236 }
 237
 238
 239 struct timespec add_msec_to_timespec(struct timespec ts, int msec)
 240 {
 241         ts.tv_sec += msec / 1000;
 242         ts.tv_nsec += (msec % 1000)*1000000;
 243         if (ts.tv_nsec >= 1000000000) {  // 10^9
 244                 ts.tv_sec++;
 245                 ts.tv_nsec -= 1000000000;
 246         }
 247         return ts;
 248 }
 249
 250
 251 int align_with_existing_timeouts(timeout *t)
 252 {
 253         GSList* it = timeout_list;
 254         while (it) {
 255                 timeout* t2 = it->data;
 256                 if (t2->interval_msec > 0) {
 257                         if (t->interval_msec % t2->interval_msec == 0 || t2->interval_msec % t->interval_msec == 0) {
 258                                 if (multi_timeouts == 0)
 259                                         multi_timeouts = g_hash_table_new(0, 0);
 260                                 if (!t->multi_timeout && !t2->multi_timeout)
 261                                         // both timeouts can be aligned, but there is no multi timeout for them
 262                                         create_multi_timeout(t, t2);
 263                                 else
 264                                         // there is already a multi timeout, so we append the new timeout to the multi timeout
 265                                         append_multi_timeout(t, t2);
 266                                 return 1;
 267                         }
 268                 }
 269                 it = it->next;
 270         }
 271         return 0;
 272 }
 273
 274
 275 int calc_multi_timeout_interval(multi_timeout_handler* mth)
 276 {
 277         GSList* it = mth->timeout_list;
 278         timeout* t = it->data;
 279         int min_interval = t->interval_msec;
 280         it = it->next;
 281         while (it) {
 282                 t = it->data;
 283                 if (t->interval_msec < min_interval)
 284                         min_interval = t->interval_msec;
 285                 it = it->next;
 286         }
 287         return min_interval;
 288 }
 289
 290
 291 void create_multi_timeout(timeout* t1, timeout* t2)
 292 {
 293         multi_timeout* mt1 = malloc(sizeof(multi_timeout));
 294         multi_timeout* mt2 = malloc(sizeof(multi_timeout));
 295         multi_timeout_handler* mth = malloc(sizeof(multi_timeout_handler));
 296         timeout* real_timeout = malloc(sizeof(timeout));
 297
 298         mth->timeout_list = 0;
 299         mth->timeout_list = g_slist_prepend(mth->timeout_list, t1);
 300         mth->timeout_list = g_slist_prepend(mth->timeout_list, t2);
 301         mth->parent_timeout = real_timeout;
 302
 303         g_hash_table_insert(multi_timeouts, t1, mth);
 304         g_hash_table_insert(multi_timeouts, t2, mth);
 305         g_hash_table_insert(multi_timeouts, real_timeout, mth);
 306
 307         t1->multi_timeout = mt1;
 308         t2->multi_timeout = mt2;
 309         // set real_timeout->multi_timeout to something, such that we see in add_timeout_intern that
 310         // it is already a multi_timeout (we never use it, except of checking for 0 ptr)
 311         real_timeout->multi_timeout = (void*)real_timeout;
 312
 313         timeout_list = g_slist_remove(timeout_list, t1);
 314         timeout_list = g_slist_remove(timeout_list, t2);
 315
 316         update_multi_timeout_values(mth);
 317 }
 318
 319
 320 void append_multi_timeout(timeout* t1, timeout* t2)
 321 {
 322         if (t2->multi_timeout) {
 323                 // swap t1 and t2 such that t1 is the multi timeout
 324                 timeout* tmp = t2;
 325                 t2 = t1;
 326                 t1 = tmp;
 327         }
 328
 329         multi_timeout* mt = malloc(sizeof(multi_timeout));
 330         multi_timeout_handler* mth = g_hash_table_lookup(multi_timeouts, t1);
 331
 332         mth->timeout_list = g_slist_prepend(mth->timeout_list, t2);
 333         g_hash_table_insert(multi_timeouts, t2, mth);
 334
 335         t2->multi_timeout = mt;
 336
 337         update_multi_timeout_values(mth);
 338 }
 339
 340
 341 void update_multi_timeout_values(multi_timeout_handler* mth)
 342 {
 343         int interval = calc_multi_timeout_interval(mth);
 344         int next_timeout_msec = interval;
 345
 346         struct timespec cur_time;
 347         clock_gettime(CLOCK_MONOTONIC, &cur_time);
 348
 349         GSList* it = mth->timeout_list;
 350         struct timespec diff_time;
 351         while (it) {
 352                 timeout* t = it->data;
 353                 t->multi_timeout->count_to_expiration = t->interval_msec / interval;
 354                 timespec_subtract(&diff_time, &t->timeout_expires, &cur_time);
 355                 int msec_to_expiration = diff_time.tv_sec*1000 + diff_time.tv_nsec/1000000;
 356                 int count_left = msec_to_expiration / interval + (msec_to_expiration%interval != 0);
 357                 t->multi_timeout->current_count = t->multi_timeout->count_to_expiration - count_left;
 358                 if (msec_to_expiration < next_timeout_msec)
 359                         next_timeout_msec = msec_to_expiration;
 360                 it = it->next;
 361         }
 362
 363         mth->parent_timeout->interval_msec = interval;
 364         timeout_list = g_slist_remove(timeout_list, mth->parent_timeout);
 365         add_timeout_intern(next_timeout_msec, interval, callback_multi_timeout, mth, mth->parent_timeout);
 366 }
 367
 368
 369 void callback_multi_timeout(void* arg)
 370 {
 371         multi_timeout_handler* mth = arg;
 372         struct timespec cur_time;
 373         clock_gettime(CLOCK_MONOTONIC, &cur_time);
 374         GSList* it = mth->timeout_list;
 375         while (it) {
 376                 timeout* t = it->data;
 377                 if (++t->multi_timeout->current_count >= t->multi_timeout->count_to_expiration) {
 378                         t->_callback(t->arg);
 379                         t->multi_timeout->current_count = 0;
 380                         t->timeout_expires = add_msec_to_timespec(cur_time, t->interval_msec);
 381                 }
 382                 it = it->next;
 383         }
 384 }
 385
 386
 387 void remove_from_multi_timeout(timeout* t)
 388 {
 389         multi_timeout_handler* mth = g_hash_table_lookup(multi_timeouts, t);
 390         g_hash_table_remove(multi_timeouts, t);
 391
 392         mth->timeout_list = g_slist_remove(mth->timeout_list, t);
 393         free(t->multi_timeout);
 394         t->multi_timeout = 0;
 395
 396         if (g_slist_length(mth->timeout_list) == 1) {
 397                 timeout* last_timeout = mth->timeout_list->data;
 398                 free(last_timeout->multi_timeout);
 399                 last_timeout->multi_timeout = 0;
 400                 g_hash_table_remove(multi_timeouts, last_timeout);
 401                 g_hash_table_remove(multi_timeouts, mth->parent_timeout);
 402                 mth->parent_timeout->multi_timeout = 0;
 403                 stop_timeout(mth->parent_timeout);
 404                 free(mth);
 405
 406                 struct timespec cur_time, diff_time;
 407                 clock_gettime(CLOCK_MONOTONIC, &cur_time);
 408                 timespec_subtract(&diff_time, &t->timeout_expires, &cur_time);
 409                 int msec_to_expiration = diff_time.tv_sec*1000 + diff_time.tv_nsec/1000000;
 410                 add_timeout_intern(msec_to_expiration, last_timeout->interval_msec, last_timeout->_callback, last_timeout->arg, last_timeout);
 411         }
 412         else
 413                 update_multi_timeout_values(mth);
 414 }
 415
 416
 417 void stop_multi_timeout(timeout* t)
 418 {
 419         multi_timeout_handler* mth = g_hash_table_lookup(multi_timeouts, t);
 420         g_hash_table_remove(multi_timeouts, mth->parent_timeout);
 421         while (mth->timeout_list) {
 422                 timeout* t1 = mth->timeout_list->data;
 423                 mth->timeout_list = g_slist_remove(mth->timeout_list, t1);
 424                 g_hash_table_remove(multi_timeouts, t1);
 425                 free(t1->multi_timeout);
 426                 free(t1);
 427         }
 428         free(mth);
 429 }