/*******************************************************************************
 * Copyright (c) 2007 Wind River Systems, Inc. and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Eclipse Public License v1.0 
 * which accompanies this distribution, and is available at 
 * http://www.eclipse.org/legal/epl-v10.html 
 *  
 * Contributors:
 *     Wind River Systems - initial API and implementation
 *******************************************************************************/

/*
 * Double linked list support.
 */

#ifndef D_link
#define D_link

typedef struct LINK LINK;

struct LINK {
    LINK * next;
    LINK * prev;
};

#define list_init(list) (list)->next = (list)->prev = (list)

#define list_is_empty(list) ((list)->next == (list) && (list)->prev == (list))

#define list_remove(item) (item)->prev->next = (item)->next; \
        (item)->next->prev = (item)->prev

#define list_add_first(item,list) (item)->next = (list)->next; (item)->prev = (list); \
        (list)->next->prev = (item); (list)->next = (item)

#define list_add_last(item,list)  (item)->next = (list); (item)->prev = (list)->prev; \
        (list)->prev->next = (item); (list)->prev = (item)

#define list_concat(item,list) if(!list_is_empty(list)) { \
            (item)->prev->next = (list)->next; \
            (list)->next->prev = (item)->prev; \
            (item)->prev = (list)->prev; \
            (list)->prev->next = (item); \
        }

#endif