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 bool list_empty(struct list_head *list);
76 static inline void list_replace(struct list_head *from, struct list_head *to)
78 if (list_empty(from)) {
81 to->prev = from->prev;
82 to->next = from->next;
83 from->next->prev = to;
84 from->prev->next = to;
88 static inline void list_del(struct list_head *item)
90 item->prev->next = item->next;
91 item->next->prev = item->prev;
92 item->prev = item->next = NULL;
95 static inline void list_delinit(struct list_head *item)
97 item->prev->next = item->next;
98 item->next->prev = item->prev;
103 static inline bool list_empty(struct list_head *list)
105 return list->next == list;
109 * Returns whether the list has exactly one element.
111 static inline bool list_is_singular(const struct list_head *list)
113 return list->next != NULL && list->next->next == list;
116 static inline unsigned list_length(struct list_head *list)
118 struct list_head *node;
120 for (node = list->next; node != list; node = node->next)
125 static inline void list_splice(struct list_head *src, struct list_head *dst)
130 src->next->prev = dst;
131 src->prev->next = dst->next;
132 dst->next->prev = src->prev;
133 dst->next = src->next;
136 static inline void list_splicetail(struct list_head *src, struct list_head *dst)
141 src->prev->next = dst;
142 src->next->prev = dst->prev;
143 dst->prev->next = src->next;
144 dst->prev = src->prev;
147 static inline void list_validate(struct list_head *list)
149 struct list_head *node;
150 assert(list->next->prev == list && list->prev->next == list);
151 for (node = list->next; node != list; node = node->next)
152 assert(node->next->prev == node && node->prev->next == node);
155 #define LIST_INITHEAD(__item) list_inithead(__item)
156 #define LIST_ADD(__item, __list) list_add(__item, __list)
157 #define LIST_ADDTAIL(__item, __list) list_addtail(__item, __list)
158 #define LIST_REPLACE(__from, __to) list_replace(__from, __to)
159 #define LIST_DEL(__item) list_del(__item)
160 #define LIST_DELINIT(__item) list_delinit(__item)
162 #define LIST_ENTRY(__type, __item, __field) \
163 ((__type *)(((char *)(__item)) - offsetof(__type, __field)))
165 #define LIST_IS_EMPTY(__list) \
166 ((__list)->next == (__list))
169 * Cast from a pointer to a member of a struct back to the containing struct.
171 * 'sample' MUST be initialized, or else the result is undefined!
174 #define container_of(ptr, sample, member) \
175 (void *)((char *)(ptr) \
176 - ((char *)&(sample)->member - (char *)(sample)))
179 #define list_first_entry(ptr, type, member) \
180 LIST_ENTRY(type, (ptr)->next, member)
182 #define list_last_entry(ptr, type, member) \
183 LIST_ENTRY(type, (ptr)->prev, member)
186 #define LIST_FOR_EACH_ENTRY(pos, head, member) \
187 for (pos = NULL, pos = container_of((head)->next, pos, member); \
188 &pos->member != (head); \
189 pos = container_of(pos->member.next, pos, member))
191 #define LIST_FOR_EACH_ENTRY_SAFE(pos, storage, head, member) \
192 for (pos = NULL, pos = container_of((head)->next, pos, member), \
193 storage = container_of(pos->member.next, pos, member); \
194 &pos->member != (head); \
195 pos = storage, storage = container_of(storage->member.next, storage, member))
197 #define LIST_FOR_EACH_ENTRY_SAFE_REV(pos, storage, head, member) \
198 for (pos = NULL, pos = container_of((head)->prev, pos, member), \
199 storage = container_of(pos->member.prev, pos, member); \
200 &pos->member != (head); \
201 pos = storage, storage = container_of(storage->member.prev, storage, member))
203 #define LIST_FOR_EACH_ENTRY_FROM(pos, start, head, member) \
204 for (pos = NULL, pos = container_of((start), pos, member); \
205 &pos->member != (head); \
206 pos = container_of(pos->member.next, pos, member))
208 #define LIST_FOR_EACH_ENTRY_FROM_REV(pos, start, head, member) \
209 for (pos = NULL, pos = container_of((start), pos, member); \
210 &pos->member != (head); \
211 pos = container_of(pos->member.prev, pos, member))
213 #define list_for_each_entry(type, pos, head, member) \
214 for (type *pos = LIST_ENTRY(type, (head)->next, member); \
215 &pos->member != (head); \
216 pos = LIST_ENTRY(type, pos->member.next, member))
218 #define list_for_each_entry_safe(type, pos, head, member) \
219 for (type *pos = LIST_ENTRY(type, (head)->next, member), \
220 *__next = LIST_ENTRY(type, pos->member.next, member); \
221 &pos->member != (head); \
223 __next = LIST_ENTRY(type, __next->member.next, member))
225 #define list_for_each_entry_rev(type, pos, head, member) \
226 for (type *pos = LIST_ENTRY(type, (head)->prev, member); \
227 &pos->member != (head); \
228 pos = LIST_ENTRY(type, pos->member.prev, member))
230 #define list_for_each_entry_safe_rev(type, pos, head, member) \
231 for (type *pos = LIST_ENTRY(type, (head)->prev, member), \
232 *__prev = LIST_ENTRY(type, pos->member.prev, member); \
233 &pos->member != (head); \
235 __prev = LIST_ENTRY(type, __prev->member.prev, member))
237 #define list_for_each_entry_from(type, pos, start, head, member) \
238 for (type *pos = LIST_ENTRY(type, (start), member); \
239 &pos->member != (head); \
240 pos = LIST_ENTRY(type, pos->member.next, member))
242 #define list_for_each_entry_from_rev(type, pos, start, head, member) \
243 for (type *pos = LIST_ENTRY(type, (start), member); \
244 &pos->member != (head); \
245 pos = LIST_ENTRY(type, pos->member.prev, member))
247 #endif /*_UTIL_LIST_H_*/