tube.c

   1 #include <stdint.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include "dat.h"
   5
   6 struct ms tubes;
   7
   8 tube
   9 make_tube(const char *name)
  10 {
  11     tube t;
  12
  13     t = new(struct tube);
  14     if (!t) return NULL;
  15
  16     t->name[MAX_TUBE_NAME_LEN - 1] = '\0';
  17     strncpy(t->name, name, MAX_TUBE_NAME_LEN - 1);
  18     if (t->name[MAX_TUBE_NAME_LEN - 1] != '\0') twarnx("truncating tube name");
  19
  20     t->ready.less = job_pri_less;
  21     t->delay.less = job_delay_less;
  22     t->ready.rec = job_setheappos;
  23     t->delay.rec = job_setheappos;
  24     t->buried = (struct job) { };
  25     t->buried.prev = t->buried.next = &t->buried;
  26     ms_init(&t->waiting, NULL, NULL);
  27
  28     return t;
  29 }
  30
  31 static void
  32 tube_free(tube t)
  33 {
  34     prot_remove_tube(t);
  35     free(t->ready.data);
  36     free(t->delay.data);
  37     ms_clear(&t->waiting);
  38     free(t);
  39 }
  40
  41 void
  42 tube_dref(tube t)
  43 {
  44     if (!t) return;
  45     if (t->refs < 1) return twarnx("refs is zero for tube: %s", t->name);
  46
  47     --t->refs;
  48     if (t->refs < 1) tube_free(t);
  49 }
  50
  51 void
  52 tube_iref(tube t)
  53 {
  54     if (!t) return;
  55     ++t->refs;
  56 }
  57
  58 static tube
  59 make_and_insert_tube(const char *name)
  60 {
  61     int r;
  62     tube t = NULL;
  63
  64     t = make_tube(name);
  65     if (!t) return NULL;
  66
  67     /* We want this global tube list to behave like "weak" refs, so don't
  68      * increment the ref count. */
  69     r = ms_append(&tubes, t);
  70     if (!r) return tube_dref(t), (tube) 0;
  71
  72     return t;
  73 }
  74
  75 tube
  76 tube_find(const char *name)
  77 {
  78     tube t;
  79     size_t i;
  80
  81     for (i = 0; i < tubes.used; i++) {
  82         t = tubes.items[i];
  83         if (strncmp(t->name, name, MAX_TUBE_NAME_LEN) == 0) return t;
  84     }
  85     return NULL;
  86 }
  87
  88 tube
  89 tube_find_or_make(const char *name)
  90 {
  91     return tube_find(name) ? : make_and_insert_tube(name);
  92 }
  93