list.h

/*
 * List code based on Linux's list.h.
 */

#ifndef __LIST_H__
#define __LIST_H__

#include <stdlib.h>

struct list_head { struct list_head *prev, *next; };

#define list_entry(ptr, type, memb) \
	((type *)((void *)ptr - (size_t)&((type *)0)->memb))

#define list_for_each(i, head) \
	for((i)=(head)->next; (i)!=(head); (i)=(i)->next)

#define list_for_each_prev(i, head) \
	for((i)=(head)->prev; (i)!=(head); (i)=(i)->prev)

#define list_for_each_entry(i, h, m) \
	for ((i) = list_entry((h)->next, typeof(*(i)), m); \
			&(i)->m != (h); \
			(i) = list_entry((i)->m.next, typeof(*(i)), m))

#define list_for_each_entry_safe(i, n, h, m) \
	for ((n) = (i) = list_entry((h)->next, typeof(*(i)), m); \
			(n) = list_entry((n)->m.next, typeof(*(i)), m), \
			&(i)->m != (h); \
			(i) = (n))

#define LIST_HEAD_INIT(name) { &(name), &(name) }
#define LIST_HEAD(name) struct list_head name = LIST_HEAD_INIT(name)
#define INIT_LIST_HEAD(list) do { \
	(list)->next = (list)->prev = (list); \
} while(0)

#define INIT_LIST_ITEM(name) { name , name }

static inline void list_head_init(struct list_head *item)
{
	item->next = item->prev = item;
}

static inline void __list_add(struct list_head *new, struct list_head *prev,
		struct list_head *next)
{
	new->next = next;
	new->prev = prev;
	next->prev = new;
	prev->next = new;
}

static inline void list_add(struct list_head *new, struct list_head *head)
{
	__list_add(new, head, head->next);
}

static inline void list_add_tail(struct list_head *new, struct list_head *head)
{
	__list_add(new, head->prev, head);
}

static inline void list_del(struct list_head *item)
{
	item->next->prev = item->prev;
	item->prev->next = item->next;
	item->next = item;
	item->prev = NULL;
}

static inline void list_del_init(struct list_head *item)
{
	list_del(item);
	INIT_LIST_HEAD(item);
}

static inline int list_empty(const struct list_head *item)
{
	return item->next == item;
}

static inline void list_move(struct list_head *item, struct list_head *head)
{
	list_del(item);
	list_add(item, head);
}

static inline void list_move_tail(struct list_head *item,
		struct list_head *head)
{
	list_del(item);
	list_add_tail(item, head);
}

static inline void __list_splice(struct list_head *list,
		struct list_head *head)
{
	struct list_head *first = list->next;
	struct list_head *last = list->prev;
	struct list_head *at = head->next;

	first->prev = head;
	head->next = first;

	last->next = at;
	at->prev = last;
}

static inline void list_splice(struct list_head *list, struct list_head *head)
{
	if (!list_empty(list))
		__list_splice(list, head);
}

static inline void list_splice_init(struct list_head *list,
				    struct list_head *head)
{
	if (!list_empty(list)) {
		__list_splice(list, head);
		list_head_init(list);
	}
}

static inline struct list_head *list_pop(struct list_head *head)
{
	struct list_head *item = head->next;
	if (item != head)
		list_del_init(item);
	return item;
}

#define list_pop_entry(head, type, member) \
	list_entry(list_pop(head), type, member)

#define list_next_entry(pos, memb) \
	list_entry((pos)->memb.next, typeof(*pos), memb)

#define list_prev_entry(pos, memb) \
	list_entry((pos)->memb.prev, typeof(*pos), memb)

#endif