1 /*
2 * Doubly-linked list
3 * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #ifndef LIST_H
10 #define LIST_H
11
12 /**
13 * struct dl_list - Doubly-linked list
14 */
15 struct dl_list {
16 struct dl_list *next;
17 struct dl_list *prev;
18 };
19
dl_list_init(struct dl_list * list)20 static inline void dl_list_init(struct dl_list *list)
21 {
22 list->next = list;
23 list->prev = list;
24 }
25
dl_list_add(struct dl_list * list,struct dl_list * item)26 static inline void dl_list_add(struct dl_list *list, struct dl_list *item)
27 {
28 item->next = list->next;
29 item->prev = list;
30 list->next->prev = item;
31 list->next = item;
32 }
33
dl_list_add_tail(struct dl_list * list,struct dl_list * item)34 static inline void dl_list_add_tail(struct dl_list *list, struct dl_list *item)
35 {
36 dl_list_add(list->prev, item);
37 }
38
dl_list_del(struct dl_list * item)39 static inline void dl_list_del(struct dl_list *item)
40 {
41 item->next->prev = item->prev;
42 item->prev->next = item->next;
43 item->next = NULL;
44 item->prev = NULL;
45 }
46
dl_list_empty(struct dl_list * list)47 static inline int dl_list_empty(struct dl_list *list)
48 {
49 return list->next == list;
50 }
51
dl_list_len(struct dl_list * list)52 static inline unsigned int dl_list_len(struct dl_list *list)
53 {
54 struct dl_list *item;
55 int count = 0;
56 for (item = list->next; item != list; item = item->next)
57 count++;
58 return count;
59 }
60
61 #ifndef offsetof
62 #define offsetof(type, member) ((long) &((type *) 0)->member)
63 #endif
64
65 #define dl_list_entry(item, type, member) \
66 ((type *) ((char *) item - offsetof(type, member)))
67
68 #define dl_list_first(list, type, member) \
69 (dl_list_empty((list)) ? NULL : \
70 dl_list_entry((list)->next, type, member))
71
72 #define dl_list_last(list, type, member) \
73 (dl_list_empty((list)) ? NULL : \
74 dl_list_entry((list)->prev, type, member))
75
76 #define dl_list_for_each(item, list, type, member) \
77 for (item = dl_list_entry((list)->next, type, member); \
78 &item->member != (list); \
79 item = dl_list_entry(item->member.next, type, member))
80
81 #define dl_list_for_each_safe(item, n, list, type, member) \
82 for (item = dl_list_entry((list)->next, type, member), \
83 n = dl_list_entry(item->member.next, type, member); \
84 &item->member != (list); \
85 item = n, n = dl_list_entry(n->member.next, type, member))
86
87 #define dl_list_for_each_reverse(item, list, type, member) \
88 for (item = dl_list_entry((list)->prev, type, member); \
89 &item->member != (list); \
90 item = dl_list_entry(item->member.prev, type, member))
91
92 #define DEFINE_DL_LIST(name) \
93 struct dl_list name = { &(name), &(name) }
94
95 #endif /* LIST_H */
96