1 /*
2 * Doubly-linked list
3 * Copyright (c) 2009-2019, 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
20 #define DL_LIST_HEAD_INIT(l) { &(l), &(l) }
21
dl_list_init(struct dl_list * list)22 static inline void dl_list_init(struct dl_list *list)
23 {
24 list->next = list;
25 list->prev = list;
26 }
27
dl_list_add(struct dl_list * list,struct dl_list * item)28 static inline void dl_list_add(struct dl_list *list, struct dl_list *item)
29 {
30 item->next = list->next;
31 item->prev = list;
32 list->next->prev = item;
33 list->next = item;
34 }
35
dl_list_add_tail(struct dl_list * list,struct dl_list * item)36 static inline void dl_list_add_tail(struct dl_list *list, struct dl_list *item)
37 {
38 dl_list_add(list->prev, item);
39 }
40
dl_list_del(struct dl_list * item)41 static inline void dl_list_del(struct dl_list *item)
42 {
43 item->next->prev = item->prev;
44 item->prev->next = item->next;
45 item->next = NULL;
46 item->prev = NULL;
47 }
48
dl_list_empty(struct dl_list * list)49 static inline int dl_list_empty(struct dl_list *list)
50 {
51 return list->next == list;
52 }
53
dl_list_len(struct dl_list * list)54 static inline unsigned int dl_list_len(struct dl_list *list)
55 {
56 struct dl_list *item;
57 int count = 0;
58 for (item = list->next; item != list; item = item->next)
59 count++;
60 return count;
61 }
62
63 #ifndef offsetof
64 #define offsetof(type, member) ((long) &((type *) 0)->member)
65 #endif
66
67 #define dl_list_entry(item, type, member) \
68 ((type *) ((char *) item - offsetof(type, member)))
69
70 #define dl_list_first(list, type, member) \
71 (dl_list_empty((list)) ? NULL : \
72 dl_list_entry((list)->next, type, member))
73
74 #define dl_list_last(list, type, member) \
75 (dl_list_empty((list)) ? NULL : \
76 dl_list_entry((list)->prev, type, member))
77
78 #define dl_list_for_each(item, list, type, member) \
79 for (item = dl_list_first((list), type, member); \
80 item && item != dl_list_entry((list), type, member); \
81 item = dl_list_entry(item->member.next, type, member))
82
83 #define dl_list_for_each_safe(item, n, list, type, member) \
84 for (item = dl_list_entry((list)->next, type, member), \
85 n = dl_list_entry(item->member.next, type, member); \
86 &item->member != (list); \
87 item = n, n = dl_list_entry(n->member.next, type, member))
88
89 #define dl_list_for_each_reverse(item, list, type, member) \
90 for (item = dl_list_entry((list)->prev, type, member); \
91 &item->member != (list); \
92 item = dl_list_entry(item->member.prev, type, member))
93
94 #define DEFINE_DL_LIST(name) \
95 struct dl_list name = { &(name), &(name) }
96
97 #endif /* LIST_H */
98