1 /**************************************************************************
3 * Copyright 2006 VMware, Inc., Bismarck, ND. USA.
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:
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.
22 * The above copyright notice and this permission notice (including the
23 * next paragraph) shall be included in all copies or substantial portions
26 **************************************************************************/
30 * List macros heavily inspired by the Linux kernel
31 * list handling. No list looping yet.
33 * Is not threadsafe, so common operations need to
34 * be protected using an external mutex.
48 struct list_head
*prev
;
49 struct list_head
*next
;
52 static inline void list_inithead(struct list_head
*item
)
58 static inline void list_add(struct list_head
*item
, struct list_head
*list
)
61 item
->next
= list
->next
;
62 list
->next
->prev
= item
;
66 static inline void list_addtail(struct list_head
*item
, struct list_head
*list
)
69 item
->prev
= list
->prev
;
70 list
->prev
->next
= item
;
74 static inline void list_replace(struct list_head
*from
, struct list_head
*to
)
76 to
->prev
= from
->prev
;
77 to
->next
= from
->next
;
78 from
->next
->prev
= to
;
79 from
->prev
->next
= to
;
82 static inline void list_del(struct list_head
*item
)
84 item
->prev
->next
= item
->next
;
85 item
->next
->prev
= item
->prev
;
86 item
->prev
= item
->next
= NULL
;
89 static inline void list_delinit(struct list_head
*item
)
91 item
->prev
->next
= item
->next
;
92 item
->next
->prev
= item
->prev
;
97 static inline bool list_empty(struct list_head
*list
)
99 return list
->next
== list
;
103 * Returns whether the list has exactly one element.
105 static inline bool list_is_singular(const struct list_head
*list
)
107 return list
->next
!= NULL
&& list
->next
->next
== list
;
110 static inline unsigned list_length(struct list_head
*list
)
112 struct list_head
*node
;
114 for (node
= list
->next
; node
!= list
; node
= node
->next
)
119 static inline void list_validate(struct list_head
*list
)
121 struct list_head
*node
;
122 assert(list
->next
->prev
== list
&& list
->prev
->next
== list
);
123 for (node
= list
->next
; node
!= list
; node
= node
->next
)
124 assert(node
->next
->prev
== node
&& node
->prev
->next
== node
);
127 #define LIST_INITHEAD(__item) list_inithead(__item)
128 #define LIST_ADD(__item, __list) list_add(__item, __list)
129 #define LIST_ADDTAIL(__item, __list) list_addtail(__item, __list)
130 #define LIST_REPLACE(__from, __to) list_replace(__from, __to)
131 #define LIST_DEL(__item) list_del(__item)
132 #define LIST_DELINIT(__item) list_delinit(__item)
134 #define LIST_ENTRY(__type, __item, __field) \
135 ((__type *)(((char *)(__item)) - offsetof(__type, __field)))
137 #define LIST_IS_EMPTY(__list) \
138 ((__list)->next == (__list))
141 * Cast from a pointer to a member of a struct back to the containing struct.
143 * 'sample' MUST be initialized, or else the result is undefined!
146 #define container_of(ptr, sample, member) \
147 (void *)((char *)(ptr) \
148 - ((char *)&(sample)->member - (char *)(sample)))
151 #define list_first_entry(ptr, type, member) \
152 LIST_ENTRY(type, (ptr)->next, member)
154 #define list_last_entry(ptr, type, member) \
155 LIST_ENTRY(type, (ptr)->prev, member)
158 #define LIST_FOR_EACH_ENTRY(pos, head, member) \
159 for (pos = NULL, pos = container_of((head)->next, pos, member); \
160 &pos->member != (head); \
161 pos = container_of(pos->member.next, pos, member))
163 #define LIST_FOR_EACH_ENTRY_SAFE(pos, storage, head, member) \
164 for (pos = NULL, pos = container_of((head)->next, pos, member), \
165 storage = container_of(pos->member.next, pos, member); \
166 &pos->member != (head); \
167 pos = storage, storage = container_of(storage->member.next, storage, member))
169 #define LIST_FOR_EACH_ENTRY_SAFE_REV(pos, storage, head, member) \
170 for (pos = NULL, pos = container_of((head)->prev, pos, member), \
171 storage = container_of(pos->member.prev, pos, member); \
172 &pos->member != (head); \
173 pos = storage, storage = container_of(storage->member.prev, storage, member))
175 #define LIST_FOR_EACH_ENTRY_FROM(pos, start, head, member) \
176 for (pos = NULL, pos = container_of((start), pos, member); \
177 &pos->member != (head); \
178 pos = container_of(pos->member.next, pos, member))
180 #define LIST_FOR_EACH_ENTRY_FROM_REV(pos, start, head, member) \
181 for (pos = NULL, pos = container_of((start), pos, member); \
182 &pos->member != (head); \
183 pos = container_of(pos->member.prev, pos, member))
185 #define list_for_each_entry(type, pos, head, member) \
186 for (type *pos = LIST_ENTRY(type, (head)->next, member); \
187 &pos->member != (head); \
188 pos = LIST_ENTRY(type, pos->member.next, member))
190 #define list_for_each_entry_safe(type, pos, head, member) \
191 for (type *pos = LIST_ENTRY(type, (head)->next, member), \
192 *__next = LIST_ENTRY(type, pos->member.next, member); \
193 &pos->member != (head); \
195 __next = LIST_ENTRY(type, __next->member.next, member))
197 #define list_for_each_entry_rev(type, pos, head, member) \
198 for (type *pos = LIST_ENTRY(type, (head)->prev, member); \
199 &pos->member != (head); \
200 pos = LIST_ENTRY(type, pos->member.prev, member))
202 #define list_for_each_entry_safe_rev(type, pos, head, member) \
203 for (type *pos = LIST_ENTRY(type, (head)->prev, member), \
204 *__prev = LIST_ENTRY(type, pos->member.prev, member); \
205 &pos->member != (head); \
207 __prev = LIST_ENTRY(type, __prev->member.prev, member))
209 #define list_for_each_entry_from(type, pos, start, head, member) \
210 for (type *pos = LIST_ENTRY(type, (start), member); \
211 &pos->member != (head); \
212 pos = LIST_ENTRY(type, pos->member.next, member))
214 #define list_for_each_entry_from_rev(type, pos, start, head, member) \
215 for (type *pos = LIST_ENTRY(type, (start), member); \
216 &pos->member != (head); \
217 pos = LIST_ENTRY(type, pos->member.prev, member))
219 #endif /*_UTIL_LIST_H_*/