#ifndef DOUBLE_LIST_INCLUDED
#define DOUBLE_LIST_INCLUDED

/**************************************************************************//**
 * @file
 * A simple double-linked list.
 *
 * @note  No thread protection so you will need to use appropriate
 * synchronization if use spans multiple threads.
 *
 * License
 * -------
 *
 * Copyright(c) <2016>, AT&T Intellectual Property.  All other rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:  This product includes
 *    software developed by the AT&T.
 * 4. Neither the name of AT&T nor the names of its contributors may be used to
 *    endorse or promote products derived from this software without specific
 *    prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY AT&T INTELLECTUAL PROPERTY ''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 AT&T INTELLECTUAL PROPERTY 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.
*****************************************************************************/

typedef struct dlist_item
{
  struct dlist_item * previous;
  struct dlist_item * next;
  void * item;
} DLIST_ITEM;

/**************************************************************************//**
 * Double-linked list structure
 *****************************************************************************/
typedef struct dlist
{
  DLIST_ITEM * head;
  DLIST_ITEM * tail;
} DLIST;


void dlist_initialize(DLIST * list);
void * dlist_pop_last(DLIST * list);
void dlist_push_first(DLIST * list, void * item);
void dlist_push_last(DLIST * list, void * item);
DLIST_ITEM * dlist_get_first(DLIST * list);
DLIST_ITEM * dlist_get_last(DLIST * list);
DLIST_ITEM * dlist_get_next(DLIST_ITEM * item);
int dlist_is_empty(DLIST * list);
int dlist_count(DLIST * list);

#endif