/*
* Copyright (c) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup libc
* @{
*/
/** @file
*/
#ifndef LIBC_LIST_H_
#define LIBC_LIST_H_
#include <unistd.h>
/** Doubly linked list head and link type. */
typedef struct link {
struct link *prev; /**< Pointer to the previous item in the list. */
struct link *next; /**< Pointer to the next item in the list. */
} link_t;
/** Declare and initialize statically allocated list.
*
* @param name Name of the new statically allocated list.
*/
#define LIST_INITIALIZE(name) link_t name = { \
.prev = &name, \
.next = &name \
}
/** Initialize doubly-linked circular list link
*
* Initialize doubly-linked list link.
*
* @param link Pointer to link_t structure to be initialized.
*/
static inline void link_initialize(link_t *link)
{
link->prev = NULL;
link->next = NULL;
}
/** Initialize doubly-linked circular list
*
* Initialize doubly-linked circular list.
*
* @param head Pointer to link_t structure representing head of the list.
*/
static inline void list_initialize(link_t *head)
{
head->prev = head;
head->next = head;
}
/** Add item to the beginning of doubly-linked circular list
*
* Add item to the beginning of doubly-linked circular list.
*
* @param link Pointer to link_t structure to be added.
* @param head Pointer to link_t structure representing head of the list.
*/
static inline void list_prepend(link_t *link, link_t *head)
{
link->next = head->next;
link->prev = head;
head->next->prev = link;
head->next = link;
}
/** Add item to the end of doubly-linked circular list
*
* Add item to the end of doubly-linked circular list.
*
* @param link Pointer to link_t structure to be added.
* @param head Pointer to link_t structure representing head of the list.
*/
static inline void list_append(link_t *link, link_t *head)
{
link->prev = head->prev;
link->next = head;
head->prev->next = link;
head->prev = link;
}
/** Insert item before another item in doubly-linked circular list. */
static inline void list_insert_before(link_t *l, link_t *r)
{
list_append(l, r);
}
/** Insert item after another item in doubly-linked circular list. */
static inline void list_insert_after(link_t *r, link_t *l)
{
list_prepend(l, r);
}
/** Remove item from doubly-linked circular list
*
* Remove item from doubly-linked circular list.
*
* @param link Pointer to link_t structure to be removed from the list it is contained in.
*/
static inline void list_remove(link_t *link)
{
link->next->prev = link->prev;
link->prev->next = link->next;
link_initialize(link);
}
/** Query emptiness of doubly-linked circular list
*
* Query emptiness of doubly-linked circular list.
*
* @param head Pointer to link_t structure representing head of the list.
*/
static inline int list_empty(link_t *head)
{
return ((head->next == head) ? 1 : 0);
}
/** Split or concatenate headless doubly-linked circular list
*
* Split or concatenate headless doubly-linked circular list.
*
* Note that the algorithm works both directions:
* concatenates splitted lists and splits concatenated lists.
*
* @param part1 Pointer to link_t structure leading the first (half of the headless) list.
* @param part2 Pointer to link_t structure leading the second (half of the headless) list.
*/
static inline void headless_list_split_or_concat(link_t *part1, link_t *part2)
{
part1->prev->next = part2;
part2->prev->next = part1;
link_t *hlp = part1->prev;
part1->prev = part2->prev;
part2->prev = hlp;
}
/** Split headless doubly-linked circular list
*
* Split headless doubly-linked circular list.
*
* @param part1 Pointer to link_t structure leading the first half of the headless list.
* @param part2 Pointer to link_t structure leading the second half of the headless list.
*/
static inline void headless_list_split(link_t *part1, link_t *part2)
{
headless_list_split_or_concat(part1, part2);
}
/** Concatenate two headless doubly-linked circular lists
*
* Concatenate two headless doubly-linked circular lists.
*
* @param part1 Pointer to link_t structure leading the first headless list.
* @param part2 Pointer to link_t structure leading the second headless list.
*/
static inline void headless_list_concat(link_t *part1, link_t *part2)
{
headless_list_split_or_concat(part1, part2);
}
#define list_get_instance(link, type, member) ((type *) (((void *)(link)) - ((void *) &(((type *) NULL)->member))))
extern int list_member(const link_t *link, const link_t *head);
extern void list_concat(link_t *head1, link_t *head2);
extern unsigned int list_count(const link_t *link);
#endif
/** @}
*/