check_wav: return error on premature end of file.
[paraslash.git] / list.h
1 /*
2 * Copied from the Linux kernel source tree, version 2.6.13.
3 *
4 * Licensed under the GPL v2 as per the whole kernel source tree.
5 *
6 */
7
8 #include <stddef.h> /* offsetof */
9 #ifndef _LINUX_LIST_H
10 #define _LINUX_LIST_H
11
12 #define container_of(ptr, type, member) ({ \
13 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
14 (type *)( (char *)__mptr - offsetof(type,member) );})
15
16 /*
17 * These are non-NULL pointers that will result in page faults
18 * under normal circumstances, used to verify that nobody uses
19 * non-initialized list entries.
20 */
21 #define LIST_POISON1 ((void *) 0x00100100)
22 #define LIST_POISON2 ((void *) 0x00200200)
23
24 /*
25 * Simple doubly linked list implementation.
26 *
27 * Some of the internal functions ("__xxx") are useful when
28 * manipulating whole lists rather than single entries, as
29 * sometimes we already know the next/prev entries and we can
30 * generate better code by using them directly rather than
31 * using the generic single-entry routines.
32 */
33
34 struct list_head {
35 struct list_head *next, *prev;
36 };
37
38 #define INIT_LIST_HEAD(ptr) do { \
39 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
40 } while (0)
41
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 }
57
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 }
70
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 }
83
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 }
96
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 }
109
110 /**
111 * list_move - delete from one list and add as another's head
112 * @list: the entry to move
113 * @head: the head that will precede our entry
114 */
115 static inline void list_move(struct list_head *list, struct list_head *head)
116 {
117 __list_del(list->prev, list->next);
118 list_add(list, head);
119 }
120
121 /**
122 * list_empty - tests whether a list is empty
123 * @head: the list to test.
124 */
125 static inline int list_empty(const struct list_head *head)
126 {
127 return head->next == head;
128 }
129
130 /**
131 * list_entry - get the struct for this entry
132 * @ptr: the &struct list_head pointer.
133 * @type: the type of the struct this is embedded in.
134 * @member: the name of the list_struct within the struct.
135 */
136 #define list_entry(ptr, type, member) \
137 container_of(ptr, type, member)
138
139 /**
140 * list_for_each_safe - iterate over a list safe against removal of list entry
141 * @pos: the &struct list_head to use as a loop counter.
142 * @n: another &struct list_head to use as temporary storage
143 * @head: the head for your list.
144 */
145 #define list_for_each_safe(pos, n, head) \
146 for (pos = (head)->next, n = pos->next; pos != (head); \
147 pos = n, n = pos->next)
148
149 /**
150 * list_for_each_entry - iterate over list of given type
151 * @pos: the type * to use as a loop counter.
152 * @head: the head for your list.
153 * @member: the name of the list_struct within the struct.
154 */
155 #define list_for_each_entry(pos, head, member) \
156 for (pos = list_entry((head)->next, typeof(*pos), member); \
157 &pos->member != (head); \
158 pos = list_entry(pos->member.next, typeof(*pos), member))
159
160 /**
161 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
162 * @pos: the type * to use as a loop counter.
163 * @n: another type * to use as temporary storage
164 * @head: the head for your list.
165 * @member: the name of the list_struct within the struct.
166 */
167 #define list_for_each_entry_safe(pos, n, head, member) \
168 for (pos = list_entry((head)->next, typeof(*pos), member), \
169 n = list_entry(pos->member.next, typeof(*pos), member); \
170 &pos->member != (head); \
171 pos = n, n = list_entry(n->member.next, typeof(*n), member))
172 /**
173 * list_for_each_entry_safe_reverse - iterate backwards over list of given type safe against
174 * removal of list entry
175 * @pos: the type * to use as a loop counter.
176 * @n: another type * to use as temporary storage
177 * @head: the head for your list.
178 * @member: the name of the list_struct within the struct.
179 */
180 #define list_for_each_entry_safe_reverse(pos, n, head, member) \
181 for (pos = list_entry((head)->prev, typeof(*pos), member), \
182 n = list_entry(pos->member.prev, typeof(*pos), member); \
183 &pos->member != (head); \
184 pos = n, n = list_entry(n->member.prev, typeof(*n), member))
185
186 #endif /* _LIST_H */