source: MondoRescue/branches/stable/mindi-busybox/e2fsprogs/blkid/list.h @ 821

Last change on this file since 821 was 821, checked in by Bruno Cornec, 14 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)

File size: 4.3 KB
Line 
1#if !defined(_BLKID_LIST_H) && !defined(LIST_HEAD)
2#define _BLKID_LIST_H
3
4#ifdef __cplusplus
5extern "C" {
6#endif
7
8#ifdef __GNUC__
9#define _INLINE_ static __inline__
10#else                         /* For Watcom C */
11#define _INLINE_ static inline
12#endif
13
14/*
15 * Simple doubly linked list implementation.
16 *
17 * Some of the internal functions ("__xxx") are useful when
18 * manipulating whole lists rather than single entries, as
19 * sometimes we already know the next/prev entries and we can
20 * generate better code by using them directly rather than
21 * using the generic single-entry routines.
22 */
23
24struct list_head {
25    struct list_head *next, *prev;
26};
27
28#define LIST_HEAD_INIT(name) { &(name), &(name) }
29
30#define LIST_HEAD(name) \
31    struct list_head name = LIST_HEAD_INIT(name)
32
33#define INIT_LIST_HEAD(ptr) do { \
34    (ptr)->next = (ptr); (ptr)->prev = (ptr); \
35} while (0)
36
37/*
38 * Insert a new entry between two known consecutive entries.
39 *
40 * This is only for internal list manipulation where we know
41 * the prev/next entries already!
42 */
43_INLINE_ void __list_add(struct list_head * add,
44    struct list_head * prev,
45    struct list_head * next)
46{
47    next->prev = add;
48    add->next = next;
49    add->prev = prev;
50    prev->next = add;
51}
52
53/**
54 * list_add - add a new entry
55 * @add:    new entry to be added
56 * @head:   list head to add it after
57 *
58 * Insert a new entry after the specified head.
59 * This is good for implementing stacks.
60 */
61_INLINE_ void list_add(struct list_head *add, struct list_head *head)
62{
63    __list_add(add, head, head->next);
64}
65
66/**
67 * list_add_tail - add a new entry
68 * @add:    new entry to be added
69 * @head:   list head to add it before
70 *
71 * Insert a new entry before the specified head.
72 * This is useful for implementing queues.
73 */
74_INLINE_ void list_add_tail(struct list_head *add, struct list_head *head)
75{
76    __list_add(add, head->prev, head);
77}
78
79/*
80 * Delete a list entry by making the prev/next entries
81 * point to each other.
82 *
83 * This is only for internal list manipulation where we know
84 * the prev/next entries already!
85 */
86_INLINE_ void __list_del(struct list_head * prev,
87                  struct list_head * next)
88{
89    next->prev = prev;
90    prev->next = next;
91}
92
93/**
94 * list_del - deletes entry from list.
95 * @entry:  the element to delete from the list.
96 *
97 * list_empty() on @entry does not return true after this, @entry is
98 * in an undefined state.
99 */
100_INLINE_ void list_del(struct list_head *entry)
101{
102    __list_del(entry->prev, entry->next);
103}
104
105/**
106 * list_del_init - deletes entry from list and reinitialize it.
107 * @entry:  the element to delete from the list.
108 */
109_INLINE_ void list_del_init(struct list_head *entry)
110{
111    __list_del(entry->prev, entry->next);
112    INIT_LIST_HEAD(entry);
113}
114
115/**
116 * list_empty - tests whether a list is empty
117 * @head:   the list to test.
118 */
119_INLINE_ int list_empty(struct list_head *head)
120{
121    return head->next == head;
122}
123
124/**
125 * list_splice - join two lists
126 * @list:   the new list to add.
127 * @head:   the place to add it in the first list.
128 */
129_INLINE_ void list_splice(struct list_head *list, struct list_head *head)
130{
131    struct list_head *first = list->next;
132
133    if (first != list) {
134        struct list_head *last = list->prev;
135        struct list_head *at = head->next;
136
137        first->prev = head;
138        head->next = first;
139
140        last->next = at;
141        at->prev = last;
142    }
143}
144
145/**
146 * list_entry - get the struct for this entry
147 * @ptr:    the &struct list_head pointer.
148 * @type:   the type of the struct this is embedded in.
149 * @member: the name of the list_struct within the struct.
150 */
151#define list_entry(ptr, type, member) \
152    ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
153
154/**
155 * list_for_each - iterate over elements in a list
156 * @pos:    the &struct list_head to use as a loop counter.
157 * @head:   the head for your list.
158 */
159#define list_for_each(pos, head) \
160    for (pos = (head)->next; pos != (head); pos = pos->next)
161
162/**
163 * list_for_each_safe - iterate over elements in a list, but don't dereference
164 *                      pos after the body is done (in case it is freed)
165 * @pos:    the &struct list_head to use as a loop counter.
166 * @pnext:  the &struct list_head to use as a pointer to the next item.
167 * @head:   the head for your list (not included in iteration).
168 */
169#define list_for_each_safe(pos, pnext, head) \
170    for (pos = (head)->next, pnext = pos->next; pos != (head); \
171         pos = pnext, pnext = pos->next)
172
173#undef _INLINE_
174
175#ifdef __cplusplus
176}
177#endif
178
179#endif /* _BLKID_LIST_H */
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