blob: a24baaa912f80564093ee536ea168775ed5ed5f3
1 | /* vi: set sw=4 ts=4: */ |
2 | #if !defined(_BLKID_LIST_H) && !defined(LIST_HEAD) |
3 | #define BLKID_LIST_H 1 |
4 | |
5 | #ifdef __cplusplus |
6 | extern "C" { |
7 | #endif |
8 | |
9 | /* |
10 | * Simple doubly linked list implementation. |
11 | * |
12 | * Some of the internal functions ("__xxx") are useful when |
13 | * manipulating whole lists rather than single entries, as |
14 | * sometimes we already know the next/prev entries and we can |
15 | * generate better code by using them directly rather than |
16 | * using the generic single-entry routines. |
17 | */ |
18 | |
19 | struct list_head { |
20 | struct list_head *next, *prev; |
21 | }; |
22 | |
23 | #define LIST_HEAD_INIT(name) { &(name), &(name) } |
24 | |
25 | #define LIST_HEAD(name) \ |
26 | struct list_head name = LIST_HEAD_INIT(name) |
27 | |
28 | #define INIT_LIST_HEAD(ptr) do { \ |
29 | (ptr)->next = (ptr); (ptr)->prev = (ptr); \ |
30 | } while (0) |
31 | |
32 | void __list_add(struct list_head * add, struct list_head * prev, struct list_head * next); |
33 | void list_add(struct list_head *add, struct list_head *head); |
34 | void list_add_tail(struct list_head *add, struct list_head *head); |
35 | void __list_del(struct list_head * prev, struct list_head * next); |
36 | void list_del(struct list_head *entry); |
37 | void list_del_init(struct list_head *entry); |
38 | int list_empty(struct list_head *head); |
39 | void list_splice(struct list_head *list, struct list_head *head); |
40 | |
41 | /** |
42 | * list_entry - get the struct for this entry |
43 | * @ptr: the &struct list_head pointer. |
44 | * @type: the type of the struct this is embedded in. |
45 | * @member: the name of the list_struct within the struct. |
46 | */ |
47 | #define list_entry(ptr, type, member) \ |
48 | ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) |
49 | |
50 | /** |
51 | * list_for_each - iterate over elements in a list |
52 | * @pos: the &struct list_head to use as a loop counter. |
53 | * @head: the head for your list. |
54 | */ |
55 | #define list_for_each(pos, head) \ |
56 | for (pos = (head)->next; pos != (head); pos = pos->next) |
57 | |
58 | /** |
59 | * list_for_each_safe - iterate over elements in a list, but don't dereference |
60 | * pos after the body is done (in case it is freed) |
61 | * @pos: the &struct list_head to use as a loop counter. |
62 | * @pnext: the &struct list_head to use as a pointer to the next item. |
63 | * @head: the head for your list (not included in iteration). |
64 | */ |
65 | #define list_for_each_safe(pos, pnext, head) \ |
66 | for (pos = (head)->next, pnext = pos->next; pos != (head); \ |
67 | pos = pnext, pnext = pos->next) |
68 | |
69 | #ifdef __cplusplus |
70 | } |
71 | #endif |
72 | |
73 | #endif |
74 |