src/main/timer.c

   1 /* Timers. */
   2
   3 #ifdef HAVE_CONFIG_H
   4 #include "config.h"
   5 #endif
   6
   7 #include "elinks.h"
   8
   9 #include "main/select.h"
  10 #include "main/timer.h"
  11 #include "util/error.h"
  12 #include "util/lists.h"
  13 #include "util/memory.h"
  14 #include "util/time.h"
  15
  16
  17 struct timer {
  18         LIST_HEAD(struct timer);
  19
  20         timeval_T interval;
  21         void (*func)(void *);
  22         void *data;
  23 };
  24
  25 /* @timers.next points to the timer with the smallest interval,
  26  * @timers.next->next to the second smallest, and so on.  */
  27 static INIT_LIST_HEAD(timers);
  28
  29 int
  30 get_timers_count(void)
  31 {
  32         return list_size(&timers);
  33
  34 }
  35
  36 void
  37 check_timers(timeval_T *last_time)
  38 {
  39         timeval_T now;
  40         timeval_T interval;
  41         struct timer *timer;
  42
  43         timeval_now(&now);
  44         timeval_sub(&interval, last_time, &now);
  45
  46         foreach (timer, timers) {
  47                 timeval_sub_interval(&timer->interval, &interval);
  48         }
  49
  50         while (!list_empty(timers)) {
  51                 timer = timers.next;
  52
  53                 if (timeval_is_positive(&timer->interval))
  54                         break;
  55
  56                 del_from_list(timer);
  57                 /* At this point, *@timer is to be considered invalid
  58                  * outside timers.c; if anything e.g. passes it to
  59                  * @kill_timer, that's a bug.  However, @timer->func
  60                  * and @check_bottom_halves can still call @kill_timer
  61                  * on other timers, so this loop must be careful not to
  62                  * keep pointers to them.  (bug 868) */
  63                 timer->func(timer->data);
  64                 mem_free(timer);
  65                 check_bottom_halves();
  66         }
  67
  68         timeval_copy(last_time, &now);
  69 }
  70
  71 /* Install a timer that calls @func(@data) after @delay milliseconds.
  72  * Store to *@id either the ID of the new timer, or TIMER_ID_UNDEF if
  73  * the timer cannot be installed.  (This function ignores the previous
  74  * value of *@id in any case.)
  75  *
  76  * When @func is called, the timer ID has become invalid.  @func
  77  * should erase the expired timer ID from all variables, so that
  78  * there's no chance it will be given to @kill_timer later.  */
  79 void
  80 install_timer(timer_id_T *id, milliseconds_T delay, void (*func)(void *), void *data)
  81 {
  82         struct timer *new_timer, *timer;
  83
  84         assert(id && delay > 0);
  85
  86         new_timer = mem_alloc(sizeof(*new_timer));
  87         *id = (timer_id_T) new_timer; /* TIMER_ID_UNDEF is NULL */
  88         if (!new_timer) return;
  89
  90         timeval_from_milliseconds(&new_timer->interval, delay);
  91         new_timer->func = func;
  92         new_timer->data = data;
  93
  94         foreach (timer, timers) {
  95                 if (timeval_cmp(&timer->interval, &new_timer->interval) >= 0)
  96                         break;
  97         }
  98
  99         add_at_pos(timer->prev, new_timer);
 100 }
 101
 102 void
 103 kill_timer(timer_id_T *id)
 104 {
 105         struct timer *timer;
 106
 107         assert(id != NULL);
 108         if (*id == TIMER_ID_UNDEF) return;
 109
 110         timer = *id;
 111         del_from_list(timer);
 112         mem_free(timer);
 113
 114         *id = TIMER_ID_UNDEF;
 115 }
 116
 117 int
 118 get_next_timer_time(timeval_T *t)
 119 {
 120         if (!list_empty(timers)) {
 121                 timeval_copy(t, &((struct timer *) &timers)->next->interval);
 122                 return 1;
 123         }
 124
 125         return 0;
 126 }