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
31 struct 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) \
40 ((type *)((uint8_t *)(el) - offsetof(type, member)))
41
init_list_head(struct list_head * head)42 static inline void init_list_head(struct list_head *head)
43 {
44 head->prev = head;
45 head->next = head;
46 }
47
48 /* insert 'el' between 'prev' and 'next' */
__list_add(struct list_head * el,struct list_head * prev,struct list_head * next)49 static inline void __list_add(struct list_head *el,
50 struct list_head *prev, struct list_head *next)
51 {
52 prev->next = el;
53 el->prev = prev;
54 el->next = next;
55 next->prev = el;
56 }
57
58 /* add 'el' at the head of the list 'head' (= after element head) */
list_add(struct list_head * el,struct list_head * head)59 static inline void list_add(struct list_head *el, struct list_head *head)
60 {
61 __list_add(el, head, head->next);
62 }
63
64 /* add 'el' at the end of the list 'head' (= before element head) */
list_add_tail(struct list_head * el,struct list_head * head)65 static inline void list_add_tail(struct list_head *el, struct list_head *head)
66 {
67 __list_add(el, head->prev, head);
68 }
69
list_del(struct list_head * el)70 static inline void list_del(struct list_head *el)
71 {
72 struct list_head *prev, *next;
73 prev = el->prev;
74 next = el->next;
75 prev->next = next;
76 next->prev = prev;
77 el->prev = NULL; /* fail safe */
78 el->next = NULL; /* fail safe */
79 }
80
list_empty(struct list_head * el)81 static inline int list_empty(struct list_head *el)
82 {
83 return el->next == el;
84 }
85
86 #define list_for_each(el, head) \
87 for(el = (head)->next; el != (head); el = el->next)
88
89 #define list_for_each_safe(el, el1, head) \
90 for(el = (head)->next, el1 = el->next; el != (head); \
91 el = el1, el1 = el->next)
92
93 #define list_for_each_prev(el, head) \
94 for(el = (head)->prev; el != (head); el = el->prev)
95
96 #define list_for_each_prev_safe(el, el1, head) \
97 for(el = (head)->prev, el1 = el->prev; el != (head); \
98 el = el1, el1 = el->prev)
99
100 #endif /* LIST_H */
101