git.ozlabs.org Git - ccan/blob - ccan/timer/_info

   1 #include <string.h>
   2 #include "config.h"
   3
   4 /**
   5  * timer - efficient implementation of rarely-expiring timers.
   6  *
   7  * This is a lazy implementation of timers: you can add and delete timers
   8  * very quickly, and they are only sorted as their expiry approaches.
   9  *
  10  * This is a common case for timeouts, which must often be set, but
  11  * rarely expire.
  12  *
  13  * Example:
  14  *      // Silly example which outputs strings until timers expire.
  15  *      #include <ccan/timer/timer.h>
  16  *      #include <ccan/time/time.h>
  17  *      #include <stdlib.h>
  18  *      #include <stdio.h>
  19  *
  20  *      struct timed_string {
  21  *              struct list_node node;
  22  *              struct timer timer;
  23  *              const char *string;
  24  *      };
  25  *
  26  *      int main(int argc, char *argv[])
  27  *      {
  28  *              struct timers timers;
  29  *              struct list_head strings;
  30  *              struct list_head expired;
  31  *              struct timed_string *s;
  32  *
  33  *              timers_init(&timers, time_now());
  34  *              list_head_init(&strings);
  35  *
  36  *              while (argv[1]) {
  37  *                      s = malloc(sizeof(*s));
  38  *                      s->string = argv[1];
  39  *                      timer_add(&timers, &s->timer,
  40  *                                timeabs_add(time_now(),
  41  *                                            time_from_msec(atol(argv[2]))));
  42  *                      list_add_tail(&strings, &s->node);
  43  *                      argv += 2;
  44  *              }
  45  *
  46  *              while (!list_empty(&strings)) {
  47  *                      struct timeabs now = time_now();
  48  *                      list_for_each(&strings, s, node)
  49  *                              printf("%s", s->string);
  50  *                      timers_expire(&timers, now, &expired);
  51  *                      while ((s = list_pop(&expired, struct timed_string,
  52  *                                           timer.list)) != NULL) {
  53  *                              list_del_from(&strings, &s->node);
  54  *                              free(s);
  55  *                      }
  56  *              }
  57  *
  58  *              exit(0);
  59  *      }
  60  *
  61  * License: LGPL (v2.1 or any later version)
  62  * Author: Rusty Russell <rusty@rustcorp.com.au>
  63  */
  64 int main(int argc, char *argv[])
  65 {
  66         /* Expect exactly one argument */
  67         if (argc != 2)
  68                 return 1;
  69
  70         if (strcmp(argv[1], "depends") == 0) {
  71                 printf("ccan/array_size\n");
  72                 printf("ccan/ilog\n");
  73                 printf("ccan/likely\n");
  74                 printf("ccan/list\n");
  75                 printf("ccan/time\n");
  76                 return 0;
  77         }
  78
  79         return 1;
  80 }