LXR busybox/e2fsprogs/old_e2fsprogs/blkid/list.h

   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
   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
  74