blob: ded78464ab4241631ef87ba79488707c123e313d [file] [log] [blame]
/*
* Doubly-linked list
* Copyright (c) 2009, Jouni Malinen <j@w1.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*/
#ifndef LIST_H
#define LIST_H
/**
* struct dl_list - Doubly-linked list
*/
struct dl_list {
struct dl_list *next;
struct dl_list *prev;
};
static inline void dl_list_init(struct dl_list *list)
{
list->next = list;
list->prev = list;
}
static inline void dl_list_add(struct dl_list *list, struct dl_list *item)
{
item->next = list->next;
item->prev = list;
list->next->prev = item;
list->next = item;
}
static inline void dl_list_add_tail(struct dl_list *list, struct dl_list *item)
{
dl_list_add(list->prev, item);
}
static inline void dl_list_del(struct dl_list *item)
{
item->next->prev = item->prev;
item->prev->next = item->next;
item->next = NULL;
item->prev = NULL;
}
static inline int dl_list_empty(struct dl_list *list)
{
return list->next == list;
}
static inline unsigned int dl_list_len(struct dl_list *list)
{
struct dl_list *item;
int count = 0;
for (item = list->next; item != list; item = item->next)
count++;
return count;
}
#ifndef offsetof
#define offsetof(type, member) ((long) &((type *) 0)->member)
#endif
#define dl_list_entry(item, type, member) \
((type *) ((char *) item - offsetof(type, member)))
#define dl_list_first(list, type, member) \
(dl_list_empty((list)) ? NULL : \
dl_list_entry((list)->next, type, member))
#define dl_list_last(list, type, member) \
(dl_list_empty((list)) ? NULL : \
dl_list_entry((list)->prev, type, member))
#define dl_list_for_each(item, list, type, member) \
for (item = dl_list_entry((list)->next, type, member); \
&item->member != (list); \
item = dl_list_entry(item->member.next, type, member))
#define dl_list_for_each_safe(item, n, list, type, member) \
for (item = dl_list_entry((list)->next, type, member), \
n = dl_list_entry(item->member.next, type, member); \
&item->member != (list); \
item = n, n = dl_list_entry(n->member.next, type, member))
#define dl_list_for_each_reverse(item, list, type, member) \
for (item = dl_list_entry((list)->prev, type, member); \
&item->member != (list); \
item = dl_list_entry(item->member.prev, type, member))
#endif /* LIST_H */