1 /**************************************************************************
2 *
3 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
18 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
19 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
20 * USE OR OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * The above copyright notice and this permission notice (including the
23 * next paragraph) shall be included in all copies or substantial portions
24 * of the Software.
25 *
26 **************************************************************************/
27
28 /**
29 * \file
30 * List macros heavily inspired by the Linux kernel
31 * list handling. No list looping yet.
32 *
33 * Is not threadsafe, so common operations need to
34 * be protected using an external mutex.
35 */
36
37 #ifndef _U_DOUBLE_LIST_H_
38 #define _U_DOUBLE_LIST_H_
39
40
41 #include <stddef.h>
42 #include "pipe/p_compiler.h"
43
44
45 struct list_head
46 {
47 struct list_head *prev;
48 struct list_head *next;
49 };
50
list_inithead(struct list_head * item)51 static INLINE void list_inithead(struct list_head *item)
52 {
53 item->prev = item;
54 item->next = item;
55 }
56
list_add(struct list_head * item,struct list_head * list)57 static INLINE void list_add(struct list_head *item, struct list_head *list)
58 {
59 item->prev = list;
60 item->next = list->next;
61 list->next->prev = item;
62 list->next = item;
63 }
64
list_addtail(struct list_head * item,struct list_head * list)65 static INLINE void list_addtail(struct list_head *item, struct list_head *list)
66 {
67 item->next = list;
68 item->prev = list->prev;
69 list->prev->next = item;
70 list->prev = item;
71 }
72
list_replace(struct list_head * from,struct list_head * to)73 static INLINE void list_replace(struct list_head *from, struct list_head *to)
74 {
75 to->prev = from->prev;
76 to->next = from->next;
77 from->next->prev = to;
78 from->prev->next = to;
79 }
80
list_del(struct list_head * item)81 static INLINE void list_del(struct list_head *item)
82 {
83 item->prev->next = item->next;
84 item->next->prev = item->prev;
85 item->prev = item->next = NULL;
86 }
87
list_delinit(struct list_head * item)88 static INLINE void list_delinit(struct list_head *item)
89 {
90 item->prev->next = item->next;
91 item->next->prev = item->prev;
92 item->next = item;
93 item->prev = item;
94 }
95
96 #define LIST_INITHEAD(__item) list_inithead(__item)
97 #define LIST_ADD(__item, __list) list_add(__item, __list)
98 #define LIST_ADDTAIL(__item, __list) list_addtail(__item, __list)
99 #define LIST_REPLACE(__from, __to) list_replace(__from, __to)
100 #define LIST_DEL(__item) list_del(__item)
101 #define LIST_DELINIT(__item) list_delinit(__item)
102
103 #define LIST_ENTRY(__type, __item, __field) \
104 ((__type *)(((char *)(__item)) - offsetof(__type, __field)))
105
106 #define LIST_IS_EMPTY(__list) \
107 ((__list)->next == (__list))
108
109 /**
110 * Cast from a pointer to a member of a struct back to the containing struct.
111 *
112 * 'sample' MUST be initialized, or else the result is undefined!
113 */
114 #ifndef container_of
115 #define container_of(ptr, sample, member) \
116 (void *)((char *)(ptr) \
117 - ((char *)&(sample)->member - (char *)(sample)))
118 #endif
119
120 #define LIST_FOR_EACH_ENTRY(pos, head, member) \
121 for (pos = NULL, pos = container_of((head)->next, pos, member); \
122 &pos->member != (head); \
123 pos = container_of(pos->member.next, pos, member))
124
125 #define LIST_FOR_EACH_ENTRY_SAFE(pos, storage, head, member) \
126 for (pos = NULL, pos = container_of((head)->next, pos, member), \
127 storage = container_of(pos->member.next, pos, member); \
128 &pos->member != (head); \
129 pos = storage, storage = container_of(storage->member.next, storage, member))
130
131 #define LIST_FOR_EACH_ENTRY_SAFE_REV(pos, storage, head, member) \
132 for (pos = NULL, pos = container_of((head)->prev, pos, member), \
133 storage = container_of(pos->member.prev, pos, member); \
134 &pos->member != (head); \
135 pos = storage, storage = container_of(storage->member.prev, storage, member))
136
137 #define LIST_FOR_EACH_ENTRY_FROM(pos, start, head, member) \
138 for (pos = NULL, pos = container_of((start), pos, member); \
139 &pos->member != (head); \
140 pos = container_of(pos->member.next, pos, member))
141
142 #define LIST_FOR_EACH_ENTRY_FROM_REV(pos, start, head, member) \
143 for (pos = NULL, pos = container_of((start), pos, member); \
144 &pos->member != (head); \
145 pos = container_of(pos->member.prev, pos, member))
146
147 #endif /*_U_DOUBLE_LIST_H_*/
148