mm.c

   1 #include <stdlib.h>
   2 #include <unistd.h>
   3 #include "mm.h"
   4
   5 struct arena {
   6         void *ptr;
   7         size_t size;
   8         struct arena *next;
   9 };
  10
  11 static struct arena *arena_head, *arena_tail;
  12
  13 void *cget_arena(size_t size, size_t nmemb)
  14 {
  15         struct arena *a;
  16
  17         if (!size || !nmemb)
  18                 return NULL;
  19
  20         a = calloc(sizeof(*a), 1);
  21         if (!a)
  22                 return NULL;
  23
  24         a->size = size * nmemb;
  25         a->ptr = calloc(size, nmemb);
  26         if (!a->ptr) {
  27                 free(a);
  28                 return NULL;
  29         }
  30
  31         if (arena_head) {
  32                 arena_tail->next = a;
  33                 arena_tail = a;
  34         }
  35         else {
  36                 arena_head = arena_tail = a;
  37         }
  38
  39         return a->ptr;
  40 }
  41
  42 void *mget_arena(size_t size)
  43 {
  44         return cget_arena(size, 1);
  45 }
  46
  47 void release_arenas(void)
  48 {
  49         struct arena *a;
  50
  51         a = arena_head;
  52         while (a) {
  53                 struct arena *next;
  54
  55                 next = a->next;
  56                 free(a->ptr);
  57                 free(a);
  58                 a = next;
  59         }
  60         arena_head = arena_tail = NULL;
  61 }