3 * This file is based on include/linux/list.h in the Linux kernel source code.
12 struct list_head *next, *prev;
15 struct hlist_node *first;
19 struct hlist_node *next, **pprev;
23 * Simple doubly linked list implementation.
25 * Some of the internal functions ("__xxx") are useful when
26 * manipulating whole lists rather than single entries, as
27 * sometimes we already know the next/prev entries and we can
28 * generate better code by using them directly rather than
29 * using the generic single-entry routines.
32 #define LIST_HEAD_INIT(name) { &(name), &(name) }
34 #ifdef LIST_HEAD /* BSD sys/queue.h defines this... */
38 #define LIST_HEAD(name) \
39 struct list_head name = LIST_HEAD_INIT(name)
41 static inline void INIT_LIST_HEAD(struct list_head *list)
48 * Insert a new entry between two known consecutive entries.
50 * This is only for internal list manipulation where we know
51 * the prev/next entries already!
53 static inline void __list_add(struct list_head *new,
54 struct list_head *prev,
55 struct list_head *next)
64 * list_add - add a new entry
65 * @new: new entry to be added
66 * @head: list head to add it after
68 * Insert a new entry after the specified head.
69 * This is good for implementing stacks.
71 static inline void list_add(struct list_head *new, struct list_head *head)
73 __list_add(new, head, head->next);
77 * list_add_tail - add a new entry
78 * @new: new entry to be added
79 * @head: list head to add it before
81 * Insert a new entry before the specified head.
82 * This is useful for implementing queues.
84 static inline void list_add_tail(struct list_head *new, struct list_head *head)
86 __list_add(new, head->prev, head);
90 * Delete a list entry by making the prev/next entries
91 * point to each other.
93 * This is only for internal list manipulation where we know
94 * the prev/next entries already!
96 static inline void __list_del(struct list_head * prev, struct list_head * next)
103 * list_del - deletes entry from list.
104 * @entry: the element to delete from the list.
105 * Note: list_empty() on entry does not return true after this, the entry is
106 * in an undefined state.
108 static inline void list_del(struct list_head *entry)
110 __list_del(entry->prev, entry->next);
114 * list_empty - tests whether a list is empty
115 * @head: the list to test.
117 static inline int list_empty(const struct list_head *head)
119 return head->next == head;
122 static inline void __list_splice(const struct list_head *list,
123 struct list_head *prev,
124 struct list_head *next)
126 struct list_head *first = list->next;
127 struct list_head *last = list->prev;
137 * list_splice - join two lists, this is designed for stacks
138 * @list: the new list to add.
139 * @head: the place to add it in the first list.
141 static inline void list_splice(const struct list_head *list,
142 struct list_head *head)
144 if (!list_empty(list))
145 __list_splice(list, head, head->next);
148 /* Move the entire list @old to the list @new, overwriting it. */
149 static inline void list_transfer(struct list_head *old,
150 struct list_head *new)
152 struct list_head *prev, *next;
154 if (list_empty(old)) {
167 * list_move - delete from one list and add as another's head
168 * @list: the entry to move
169 * @head: the head that will precede our entry
171 static inline void list_move(struct list_head *list, struct list_head *head)
174 list_add(list, head);
178 * list_move_tail - delete from one list and add as another's tail
179 * @list: the entry to move
180 * @head: the head that will follow our entry
182 static inline void list_move_tail(struct list_head *list,
183 struct list_head *head)
186 list_add_tail(list, head);
190 * list_splice_tail - join two lists, each list being a queue
191 * @list: the new list to add.
192 * @head: the place to add it in the first list.
194 static inline void list_splice_tail(struct list_head *list,
195 struct list_head *head)
197 if (!list_empty(list))
198 __list_splice(list, head->prev, head);
202 * list_entry - get the struct for this entry
203 * @ptr: the &struct list_head pointer.
204 * @type: the type of the struct this is embedded in.
205 * @member: the name of the list_struct within the struct.
207 #define list_entry(ptr, type, member) \
208 container_of(ptr, type, member)
211 * list_for_each - iterate over a list
212 * @pos: the &struct list_head to use as a loop cursor.
213 * @head: the head for your list.
215 #define list_for_each(pos, head) \
216 for (pos = (head)->next; pos != (head); pos = pos->next)
219 * list_for_each_safe - iterate over a list safe against removal of list entry
220 * @pos: the &struct list_head to use as a loop cursor.
221 * @n: another &struct list_head to use as temporary storage
222 * @head: the head for your list.
224 #define list_for_each_safe(pos, n, head) \
225 for (pos = (head)->next, n = pos->next; pos != (head); \
226 pos = n, n = pos->next)
229 * list_for_each_entry - iterate over list of given type
230 * @pos: the type * to use as a loop cursor.
231 * @head: the head for your list.
232 * @member: the name of the list_struct within the struct.
234 #define list_for_each_entry(pos, head, member) \
235 for (pos = list_entry((head)->next, typeof(*pos), member); \
236 &pos->member != (head); \
237 pos = list_entry(pos->member.next, typeof(*pos), member))
240 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
241 * @pos: the type * to use as a loop cursor.
242 * @n: another type * to use as temporary storage
243 * @head: the head for your list.
244 * @member: the name of the list_struct within the struct.
246 #define list_for_each_entry_safe(pos, n, head, member) \
247 for (pos = list_entry((head)->next, typeof(*pos), member), \
248 n = list_entry(pos->member.next, typeof(*pos), member); \
249 &pos->member != (head); \
250 pos = n, n = list_entry(n->member.next, typeof(*n), member))
253 * Double linked lists with a single pointer list head.
254 * Mostly useful for hash tables where the two pointer list head is
256 * You lose the ability to access the tail in O(1).
259 #define HLIST_HEAD_INIT { .first = NULL }
260 #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL }
261 #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
262 static inline void INIT_HLIST_NODE(struct hlist_node *h)
268 static inline void hlist_del(struct hlist_node *n)
270 struct hlist_node *next = n->next;
271 struct hlist_node **pprev = n->pprev;
277 static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
279 struct hlist_node *first = h->first;
282 first->pprev = &n->next;
284 n->pprev = &h->first;
287 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
289 #define hlist_for_each(pos, head) \
290 for (pos = (head)->first; pos ; pos = pos->next)
292 #define hlist_for_each_safe(pos, n, head) \
293 for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
297 * hlist_for_each_entry - iterate over list of given type
298 * @tpos: the type * to use as a loop cursor.
299 * @pos: the &struct hlist_node to use as a loop cursor.
300 * @head: the head for your list.
301 * @member: the name of the hlist_node within the struct.
303 #define hlist_for_each_entry(tpos, pos, head, member) \
304 for (pos = (head)->first; \
306 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
310 * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
311 * @tpos: the type * to use as a loop cursor.
312 * @pos: the &struct hlist_node to use as a loop cursor.
313 * @n: another &struct hlist_node to use as temporary storage
314 * @head: the head for your list.
315 * @member: the name of the hlist_node within the struct.
317 #define hlist_for_each_entry_safe(tpos, pos, n, head, member) \
318 for (pos = (head)->first; \
319 pos && ({ n = pos->next; 1; }) && \
320 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \