1/* vi: set sw=4 ts=4: */ 2#if !defined(_BLKID_LIST_H) && !defined(LIST_HEAD) 3#define _BLKID_LIST_H 4 5#ifdef __cplusplus 6extern "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 19struct 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 32void __list_add(struct list_head * add, struct list_head * prev, struct list_head * next); 33void list_add(struct list_head *add, struct list_head *head); 34void list_add_tail(struct list_head *add, struct list_head *head); 35void __list_del(struct list_head * prev, struct list_head * next); 36void list_del(struct list_head *entry); 37void list_del_init(struct list_head *entry); 38int list_empty(struct list_head *head); 39void 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 /* _BLKID_LIST_H */ 74