e2fsprogs/blkid/list.h

/* vi: set sw=4 ts=4: */
#if !defined(_BLKID_LIST_H) && !defined(LIST_HEAD)
#define _BLKID_LIST_H

#ifdef __cplusplus
extern "C" {
#endif

/*
 * Simple doubly linked list implementation.
 *
 * Some of the internal functions ("__xxx") are useful when
 * manipulating whole lists rather than single entries, as
 * sometimes we already know the next/prev entries and we can
 * generate better code by using them directly rather than
 * using the generic single-entry routines.
 */

struct list_head {
	struct list_head *next, *prev;
};

#define LIST_HEAD_INIT(name) { &(name), &(name) }

#define LIST_HEAD(name) \
	struct list_head name = LIST_HEAD_INIT(name)

#define INIT_LIST_HEAD(ptr) do { \
	(ptr)->next = (ptr); (ptr)->prev = (ptr); \
} while (0)

void __list_add(struct list_head * add, struct list_head * prev,	struct list_head * next);
void list_add(struct list_head *add, struct list_head *head);
void list_add_tail(struct list_head *add, struct list_head *head);
void __list_del(struct list_head * prev, struct list_head * next);
void list_del(struct list_head *entry);
void list_del_init(struct list_head *entry);
int list_empty(struct list_head *head);
void list_splice(struct list_head *list, struct list_head *head);

/**
 * list_entry - get the struct for this entry
 * @ptr:	the &struct list_head pointer.
 * @type:	the type of the struct this is embedded in.
 * @member:	the name of the list_struct within the struct.
 */
#define list_entry(ptr, type, member) \
	((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))

/**
 * list_for_each - iterate over elements in a list
 * @pos:	the &struct list_head to use as a loop counter.
 * @head:	the head for your list.
 */
#define list_for_each(pos, head) \
	for (pos = (head)->next; pos != (head); pos = pos->next)

/**
 * list_for_each_safe - iterate over elements in a list, but don't dereference
 *                      pos after the body is done (in case it is freed)
 * @pos:	the &struct list_head to use as a loop counter.
 * @pnext:	the &struct list_head to use as a pointer to the next item.
 * @head:	the head for your list (not included in iteration).
 */
#define list_for_each_safe(pos, pnext, head) \
	for (pos = (head)->next, pnext = pos->next; pos != (head); \
	     pos = pnext, pnext = pos->next)

#ifdef __cplusplus
}
#endif

#endif /* _BLKID_LIST_H */