/*

 *

 * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND. USA.

 * All Rights Reserved.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the

 * "Software"), to deal in the Software without restriction, including

 * without limitation the rights to use, copy, modify, merge, publish,

 * distribute, sub license, and/or sell copies of the Software, and to

 * permit persons to whom the Software is furnished to do so, subject to

 * the following conditions:

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL

 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,

 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE

 * USE OR OTHER DEALINGS IN THE SOFTWARE.

 *

 * The above copyright notice and this permission notice (including the

 * next paragraph) shall be included in all copies or substantial portions

 * of the Software.

 *

 */

/**

 * \file

 * List macros heavily inspired by the Linux kernel

 * list handling. No list looping yet.

 *

 * Is not threadsafe, so common operations need to

 * be protected using an external mutex.

 */

#ifndef _U_DOUBLE_LIST_H_

#define _U_DOUBLE_LIST_H_

#include <stddef.h>

struct list_head

{

    struct list_head *prev;

    struct list_head *next;

};

static inline void list_inithead(struct list_head *item)

{

    item->prev = item;

    item->next = item;

}

static inline void list_add(struct list_head *item, struct list_head *list)

{

    item->prev = list;

    item->next = list->next;

    list->next->prev = item;

    list->next = item;

}

static inline void list_addtail(struct list_head *item, struct list_head *list)

{

    item->next = list;

    item->prev = list->prev;

    list->prev->next = item;

    list->prev = item;

}

static inline void list_replace(struct list_head *from, struct list_head *to)

{

    to->prev = from->prev;

    to->next = from->next;

    from->next->prev = to;

    from->prev->next = to;

}

static inline void list_del(struct list_head *item)

{

    item->prev->next = item->next;

    item->next->prev = item->prev;

}

static inline void list_delinit(struct list_head *item)

{

    item->prev->next = item->next;

    item->next->prev = item->prev;

    item->next = item;

    item->prev = item;

}

#define LIST_INITHEAD(__item) list_inithead(__item)

#define LIST_ADD(__item, __list) list_add(__item, __list)

#define LIST_ADDTAIL(__item, __list) list_addtail(__item, __list)

#define LIST_REPLACE(__from, __to) list_replace(__from, __to)

#define LIST_DEL(__item) list_del(__item)

#define LIST_DELINIT(__item) list_delinit(__item)

#define LIST_ENTRY(__type, __item, __field)   \

    ((__type *)(((char *)(__item)) - offsetof(__type, __field)))

#define LIST_FIRST_ENTRY(__ptr, __type, __field)   \

    LIST_ENTRY(__type, (__ptr)->next, __field)

#define LIST_LAST_ENTRY(__ptr, __type, __field)   \

    LIST_ENTRY(__type, (__ptr)->prev, __field)

#define LIST_IS_EMPTY(__list)                   \

    ((__list)->next == (__list))

#ifndef container_of

#define container_of(ptr, sample, member)				\

    (void *)((char *)(ptr)						\

	     - ((char *)&((typeof(sample))0)->member))

#endif

#define LIST_FOR_EACH_ENTRY(pos, head, member)				\

   for (pos = container_of((head)->next, pos, member);			\

	&pos->member != (head);						\

	pos = container_of(pos->member.next, pos, member))

#define LIST_FOR_EACH_ENTRY_SAFE(pos, storage, head, member)	\

   for (pos = container_of((head)->next, pos, member),			\

	storage = container_of(pos->member.next, pos, member);	\

	&pos->member != (head);						\

	pos = storage, storage = container_of(storage->member.next, storage, member))

#define LIST_FOR_EACH_ENTRY_SAFE_REV(pos, storage, head, member)	\

   for (pos = container_of((head)->prev, pos, member),			\

	storage = container_of(pos->member.prev, pos, member);		\

	&pos->member != (head);						\

	pos = storage, storage = container_of(storage->member.prev, storage, member))

#define LIST_FOR_EACH_ENTRY_FROM(pos, start, head, member)		\

   for (pos = container_of((start), pos, member);			\

	&pos->member != (head);						\

	pos = container_of(pos->member.next, pos, member))

#define LIST_FOR_EACH_ENTRY_FROM_REV(pos, start, head, member)		\

   for (pos = container_of((start), pos, member);			\

	&pos->member != (head);						\

	pos = container_of(pos->member.prev, pos, member))

#endif /*_U_DOUBLE_LIST_H_*/