#ifndef __LIST__
#define __LIST__

/**
  * ciruclar double linked list implementation
  *
  **/

#include<stdio.h>

struct list {
	struct list *next;
	struct list *prev;
};

#define LIST_INIT(name)	do { (name)->next = (name); (name)->prev = (name); } while(0);

static int inline __list_insert(struct list *prev, struct list *new, struct list *next)
{
	prev->next = new;
	new->prev = prev;
	new->next = next;
	next->prev = new;
}

static int inline list_insert_after(struct list *list, struct list *new_elem)
{
	return __list_insert(list, new_elem, list->next);
}

static int inline list_insert_before(struct list *list, struct list *new_elem)
{
	return __list_insert(list->prev, new_elem, list);
}

static void inline __list_delete(struct list *prev, struct list *elem, struct list *next)
{
	prev->next = next;
	next->prev = prev;
	elem->next = elem;
	elem->prev = elem;
}
static void inline list_delete(struct list *elem)
{
	__list_delete(elem->prev, elem, elem->next);
}

#define list_get_prev(elem)	(elem)->prev
#define list_get_next(elem)	(elem)->next

#define LIST_FOR_EACH(pos, head)	for(pos = head->next; pos != head; pos = pos->next)
#define CONTAINER_OF(ptr, type, member)	((type *)((char *)(ptr) - (unsigned long)(&((type *)0)->member)))

#endif