debuggers.hg

view tools/vnet/vnetd/list.h @ 0:7d21f7218375

Exact replica of unstable on 051908 + README-this
author Mukesh Rathor
date Mon May 19 15:34:57 2008 -0700 (2008-05-19)
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1 #ifndef _VNETD_LIST_H_
2 #define _VNETD_LIST_H_
4 /* Taken from Linux kernel code, but de-kernelized for userspace. */
5 #include <stddef.h>
7 /*
8 * These are non-NULL pointers that will result in page faults
9 * under normal circumstances, used to verify that nobody uses
10 * non-initialized list entries.
11 */
12 #define LIST_POISON1 ((void *) 0x00100100)
13 #define LIST_POISON2 ((void *) 0x00200200)
15 #define container_of(ptr, type, member) ({ \
16 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
17 (type *)( (char *)__mptr - offsetof(type,member) );})
19 /*
20 * Simple doubly linked list implementation.
21 *
22 * Some of the internal functions ("__xxx") are useful when
23 * manipulating whole lists rather than single entries, as
24 * sometimes we already know the next/prev entries and we can
25 * generate better code by using them directly rather than
26 * using the generic single-entry routines.
27 */
29 struct list_head {
30 struct list_head *next, *prev;
31 };
33 #define LIST_HEAD_INIT(name) { &(name), &(name) }
35 #define LIST_HEAD(name) \
36 struct list_head name = LIST_HEAD_INIT(name)
38 #define INIT_LIST_HEAD(ptr) do { \
39 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
40 } while (0)
42 /*
43 * Insert a new entry between two known consecutive entries.
44 *
45 * This is only for internal list manipulation where we know
46 * the prev/next entries already!
47 */
48 static inline void __list_add(struct list_head *new,
49 struct list_head *prev,
50 struct list_head *next)
51 {
52 next->prev = new;
53 new->next = next;
54 new->prev = prev;
55 prev->next = new;
56 }
58 /**
59 * list_add - add a new entry
60 * @new: new entry to be added
61 * @head: list head to add it after
62 *
63 * Insert a new entry after the specified head.
64 * This is good for implementing stacks.
65 */
66 static inline void list_add(struct list_head *new, struct list_head *head)
67 {
68 __list_add(new, head, head->next);
69 }
71 /**
72 * list_add_tail - add a new entry
73 * @new: new entry to be added
74 * @head: list head to add it before
75 *
76 * Insert a new entry before the specified head.
77 * This is useful for implementing queues.
78 */
79 static inline void list_add_tail(struct list_head *new, struct list_head *head)
80 {
81 __list_add(new, head->prev, head);
82 }
84 /*
85 * Delete a list entry by making the prev/next entries
86 * point to each other.
87 *
88 * This is only for internal list manipulation where we know
89 * the prev/next entries already!
90 */
91 static inline void __list_del(struct list_head * prev, struct list_head * next)
92 {
93 next->prev = prev;
94 prev->next = next;
95 }
97 /**
98 * list_del - deletes entry from list.
99 * @entry: the element to delete from the list.
100 * Note: list_empty on entry does not return true after this, the entry is
101 * in an undefined state.
102 */
103 static inline void list_del(struct list_head *entry)
104 {
105 __list_del(entry->prev, entry->next);
106 entry->next = LIST_POISON1;
107 entry->prev = LIST_POISON2;
108 }
110 /**
111 * list_del_rcu - deletes entry from list without re-initialization
112 * @entry: the element to delete from the list.
113 *
114 * Note: list_empty on entry does not return true after this,
115 * the entry is in an undefined state. It is useful for RCU based
116 * lockfree traversal.
117 *
118 * In particular, it means that we can not poison the forward
119 * pointers that may still be used for walking the list.
120 */
121 static inline void list_del_rcu(struct list_head *entry)
122 {
123 __list_del(entry->prev, entry->next);
124 entry->prev = LIST_POISON2;
125 }
127 /**
128 * list_del_init - deletes entry from list and reinitialize it.
129 * @entry: the element to delete from the list.
130 */
131 static inline void list_del_init(struct list_head *entry)
132 {
133 __list_del(entry->prev, entry->next);
134 INIT_LIST_HEAD(entry);
135 }
137 /**
138 * list_move - delete from one list and add as another's head
139 * @list: the entry to move
140 * @head: the head that will precede our entry
141 */
142 static inline void list_move(struct list_head *list, struct list_head *head)
143 {
144 __list_del(list->prev, list->next);
145 list_add(list, head);
146 }
148 /**
149 * list_move_tail - delete from one list and add as another's tail
150 * @list: the entry to move
151 * @head: the head that will follow our entry
152 */
153 static inline void list_move_tail(struct list_head *list,
154 struct list_head *head)
155 {
156 __list_del(list->prev, list->next);
157 list_add_tail(list, head);
158 }
160 /**
161 * list_empty - tests whether a list is empty
162 * @head: the list to test.
163 */
164 static inline int list_empty(struct list_head *head)
165 {
166 return head->next == head;
167 }
169 static inline void __list_splice(struct list_head *list,
170 struct list_head *head)
171 {
172 struct list_head *first = list->next;
173 struct list_head *last = list->prev;
174 struct list_head *at = head->next;
176 first->prev = head;
177 head->next = first;
179 last->next = at;
180 at->prev = last;
181 }
183 /**
184 * list_splice - join two lists
185 * @list: the new list to add.
186 * @head: the place to add it in the first list.
187 */
188 static inline void list_splice(struct list_head *list, struct list_head *head)
189 {
190 if (!list_empty(list))
191 __list_splice(list, head);
192 }
194 /**
195 * list_splice_init - join two lists and reinitialise the emptied list.
196 * @list: the new list to add.
197 * @head: the place to add it in the first list.
198 *
199 * The list at @list is reinitialised
200 */
201 static inline void list_splice_init(struct list_head *list,
202 struct list_head *head)
203 {
204 if (!list_empty(list)) {
205 __list_splice(list, head);
206 INIT_LIST_HEAD(list);
207 }
208 }
210 /**
211 * list_entry - get the struct for this entry
212 * @ptr: the &struct list_head pointer.
213 * @type: the type of the struct this is embedded in.
214 * @member: the name of the list_struct within the struct.
215 */
216 #define list_entry(ptr, type, member) \
217 container_of(ptr, type, member)
219 /**
220 * list_for_each - iterate over a list
221 * @pos: the &struct list_head to use as a loop counter.
222 * @head: the head for your list.
223 */
224 #define list_for_each(pos, head) \
225 for (pos = (head)->next; pos != (head); pos = pos->next)
227 /**
228 * list_for_each_prev - iterate over a list backwards
229 * @pos: the &struct list_head to use as a loop counter.
230 * @head: the head for your list.
231 */
232 #define list_for_each_prev(pos, head) \
233 for (pos = (head)->prev; pos != (head); pos = pos->prev)
235 /**
236 * list_for_each_safe - iterate over a list safe against removal of list entry
237 * @pos: the &struct list_head to use as a loop counter.
238 * @n: another &struct list_head to use as temporary storage
239 * @head: the head for your list.
240 */
241 #define list_for_each_safe(pos, n, head) \
242 for (pos = (head)->next, n = pos->next; pos != (head); \
243 pos = n, n = pos->next)
245 /**
246 * list_for_each_entry - iterate over list of given type
247 * @pos: the type * to use as a loop counter.
248 * @head: the head for your list.
249 * @member: the name of the list_struct within the struct.
250 */
251 #define list_for_each_entry(pos, head, member) \
252 for (pos = list_entry((head)->next, typeof(*pos), member); \
253 &pos->member != (head); \
254 pos = list_entry(pos->member.next, typeof(*pos), member))
256 /**
257 * list_for_each_entry_reverse - iterate backwards over list of given type.
258 * @pos: the type * to use as a loop counter.
259 * @head: the head for your list.
260 * @member: the name of the list_struct within the struct.
261 */
262 #define list_for_each_entry_reverse(pos, head, member) \
263 for (pos = list_entry((head)->prev, typeof(*pos), member); \
264 &pos->member != (head); \
265 pos = list_entry(pos->member.prev, typeof(*pos), member))
268 /**
269 * list_for_each_entry_safe - iterate over list of given type safe against
270 * removal of list entry
271 * @pos: the type * to use as a loop counter.
272 * @n: another type * to use as temporary storage
273 * @head: the head for your list.
274 * @member: the name of the list_struct within the struct.
275 */
276 #define list_for_each_entry_safe(pos, n, head, member) \
277 for (pos = list_entry((head)->next, typeof(*pos), member), \
278 n = list_entry(pos->member.next, typeof(*pos), member); \
279 &pos->member != (head); \
280 pos = n, n = list_entry(n->member.next, typeof(*n), member))
284 #endif /* _VNETD_LIST_H_ */