3 void *(*const __realloc_dep)(void *, size_t) = realloc;
7 struct chunk *next, *prev;
10 #define OVERHEAD (2*sizeof(size_t))
11 #define CHUNK_SIZE(c) ((c)->csize & -2)
12 #define MEM_TO_CHUNK(p) (struct chunk *)((char *)(p) - OVERHEAD)
14 size_t malloc_usable_size(void *p)
16 return CHUNK_SIZE(MEM_TO_CHUNK(p)) - OVERHEAD;