1/*
2 * Linux klist like system
3 *
4 * Copyright (c) 2016-2017 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24#ifndef LIST_H
25#define LIST_H
26
27#ifndef NULL
28#include <stddef.h>
29#endif
30
31struct list_head {
32 struct list_head *prev;
33 struct list_head *next;
34};
35
36#define LIST_HEAD_INIT(el) { &(el), &(el) }
37
38/* return the pointer of type 'type *' containing 'el' as field 'member' */
39#define list_entry(el, type, member) container_of(el, type, member)
40
41static inline void init_list_head(struct list_head *head)
42{
43 head->prev = head;
44 head->next = head;
45}
46
47/* insert 'el' between 'prev' and 'next' */
48static inline void __list_add(struct list_head *el,
49 struct list_head *prev, struct list_head *next)
50{
51 prev->next = el;
52 el->prev = prev;
53 el->next = next;
54 next->prev = el;
55}
56
57/* add 'el' at the head of the list 'head' (= after element head) */
58static inline void list_add(struct list_head *el, struct list_head *head)
59{
60 __list_add(el, head, head->next);
61}
62
63/* add 'el' at the end of the list 'head' (= before element head) */
64static inline void list_add_tail(struct list_head *el, struct list_head *head)
65{
66 __list_add(el, head->prev, head);
67}
68
69static inline void list_del(struct list_head *el)
70{
71 struct list_head *prev, *next;
72 prev = el->prev;
73 next = el->next;
74 prev->next = next;
75 next->prev = prev;
76 el->prev = NULL; /* fail safe */
77 el->next = NULL; /* fail safe */
78}
79
80static inline int list_empty(struct list_head *el)
81{
82 return el->next == el;
83}
84
85#define list_for_each(el, head) \
86 for(el = (head)->next; el != (head); el = el->next)
87
88#define list_for_each_safe(el, el1, head) \
89 for(el = (head)->next, el1 = el->next; el != (head); \
90 el = el1, el1 = el->next)
91
92#define list_for_each_prev(el, head) \
93 for(el = (head)->prev; el != (head); el = el->prev)
94
95#define list_for_each_prev_safe(el, el1, head) \
96 for(el = (head)->prev, el1 = el->prev; el != (head); \
97 el = el1, el1 = el->prev)
98
99#endif /* LIST_H */
100