release/src/router/busybox/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
   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