gistfile1.txt

#ifndef MG_FREELIST_EXTERN
#define MG_FREELIST_EXTERN extern
#endif

#ifndef MG_FREELIST_INTERN
#define MG_FREELIST_INTERN static
#endif

//mandatory
#ifndef MG_FREELIST_FREE_FN_NAME
#error "Must define MG_FREELIST_FREE_FN_NAME"
#endif

#ifndef MG_FREELIST_TYPE
#error "Must define MG_FREELIST_TYPE"
#endif

#ifndef MG_FREELIST_NEW_FN_NAME
#error "Must define MG_FREELIST_NEW_FN_NAME"
#endif

//optional
#ifndef MG_FREELIST_NEXT_NAME
#define MG_FREELIST_NEXT_NAME		next
#endif

#ifndef MG_FREELIST_PREV_NAME
#define MG_FREELIST_PREV_NAME		prev
#endif

#ifndef MG_FREELIST_FREE_FN
#define MG_FREELIST_FREE_FN(element)
#endif

#ifndef MG_FREELIST_INIT_FN
#define MG_FREELIST_INIT_FN(element)
#endif

#ifndef MG_FREELIST_ASSERT_ON_ALLOC_FAIL
#define MG_FREELIST_ASSERT_ON_ALLOC_FAIL(expr)
#endif

//MG_LINKEDLIST  //#define this if you want have mg_linkedlist.h and want all the linked list functionatily as well

#if !defined(MG_FREELIST_NEW_MSTACK) && !defined (MG_FREELIST_NEW_MEMORY)
#define MG_FREELIST_NEW_MALLOC malloc
#endif

#ifdef MG_FREELIST_NEW_MSTACK
MG_FREELIST_INTERN MG_FREELIST_TYPE *MG_FREELIST_NEW_FN_NAME(MG_FREELIST_TYPE *prev, MG_FREELIST_TYPE **freelist, mgMemStack *mstack, MG_FREELIST_TYPE **opt_root = 0) {
#define __MG_FREELIST_ALLOC_NEW_NODE res = (MG_FREELIST_TYPE *)mg_memStackPush(mstack, sizeof(MG_FREELIST_TYPE), true);
#elif defined(MG_FREELIST_NEW_MEMORY)
MG_FREELIST_INTERN MG_FREELIST_TYPE *MG_FREELIST_NEW_FN_NAME(MG_FREELIST_TYPE *prev, MG_FREELIST_TYPE **freelist, void *mem, MG_FREELIST_TYPE **opt_root = 0) {
#define __MG_FREELIST_ALLOC_NEW_NODE res = (MG_FREELIST_TYPE *)mem;
#else
MG_FREELIST_INTERN MG_FREELIST_TYPE *MG_FREELIST_NEW_FN_NAME(MG_FREELIST_TYPE *prev, MG_FREELIST_TYPE **freelist, MG_FREELIST_TYPE **opt_root = 0) {
#define __MG_FREELIST_ALLOC_NEW_NODE res = (MG_FREELIST_TYPE *) MG_FREELIST_NEW_MALLOC(sizeof(MG_FREELIST_TYPE), true);
#endif
	MG_FREELIST_TYPE *res = 0;
	if (*freelist) {
		res = *freelist;
		*freelist = (*freelist)->MG_FREELIST_NEXT_NAME;
		if (res->MG_FREELIST_NEXT_NAME) {
			res->MG_FREELIST_NEXT_NAME->MG_FREELIST_PREV_NAME = 0;
		}
	} else {
		__MG_FREELIST_ALLOC_NEW_NODE;
	}
	if (!res) {
		MG_FREELIST_ASSERT_ON_ALLOC_FAIL(false);
		return 0;
	}
	if (prev) {
		res->MG_FREELIST_NEXT_NAME = prev->MG_FREELIST_NEXT_NAME;
		prev->MG_FREELIST_NEXT_NAME = res;
	} else {
		res->MG_FREELIST_NEXT_NAME = 0;
	}
	res->MG_FREELIST_PREV_NAME = prev;

	if (opt_root && !*opt_root) {
		*opt_root = res;
	}
	MG_FREELIST_INIT_FN(res);
	return res;
}

MG_FREELIST_INTERN MG_FREELIST_TYPE *MG_FREELIST_FREE_FN_NAME(MG_FREELIST_TYPE *item, MG_FREELIST_TYPE **free_list, MG_FREELIST_TYPE **opt_root = 0) {
	MG_FREELIST_TYPE *passed_in_item = item;
	MG_FREELIST_TYPE *passed_in_next = item->next;
	MG_FREELIST_TYPE *next = item->MG_FREELIST_NEXT_NAME;
	if (*free_list) {
		MG_ASSERT((*free_list)->MG_FREELIST_PREV_NAME == 0);
		(*free_list)->MG_FREELIST_PREV_NAME = item;
	}

	if (item->MG_FREELIST_PREV_NAME) {
		item->MG_FREELIST_PREV_NAME->MG_FREELIST_NEXT_NAME = item->MG_FREELIST_NEXT_NAME;
	}
	if (item->MG_FREELIST_NEXT_NAME) {
		item->MG_FREELIST_NEXT_NAME->MG_FREELIST_PREV_NAME = item->MG_FREELIST_PREV_NAME;
	}
	item->MG_FREELIST_PREV_NAME = 0;
	item->MG_FREELIST_NEXT_NAME = (*free_list);
	*free_list = item;

	MG_FREELIST_FREE_FN(item);
	if (opt_root && *opt_root == passed_in_item) {
		*opt_root = passed_in_next;
	}
	return next;
}


#ifdef MG_FREELIST_GEN_LINKEDLIST
#define MG_LINKEDLIST_TYPE					MG_FREELIST_TYPE
#include "mg_linkedlist.h"
#endif

#undef MG_FREELIST_FREE_FN_NAME
#undef MG_FREELIST_NEW_FN_NAME

#undef MG_FREELIST_TYPE
#undef MG_FREELIST_NEXT_NAME
#undef MG_FREELIST_PREV_NAME
#undef MG_FREELIST_FREE_FN
#undef MG_FREELIST_INIT_FN
#undef __MG_FREELIST_ALLOC_NEW_NODE
#undef MG_FREELIST_ASSERT_ON_ALLOC_FAIL

#ifdef MG_FREELIST_NEW_MSTACK
#undef MG_FREELIST_NEW_MSTACK
#endif

#ifdef MG_FREELIST_NEW_MEMORY
#undef MG_FREELIST_NEW_MEMORY
#endif

#ifdef MG_FREELIST_NEW_MALLOC
#undef MG_FREELIST_NEW_MALLOC
#endif