/* * Copyright (c) 2017, George Oikonomou - http://www.spd.gr * Copyright (c) 2017, James Pope * All 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. Neither the name of the copyright holder 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``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 * COPYRIGHT HOLDER OR CONTRIBUTORS 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 data * @{ * * \defgroup circular-singly-linked-list Circular, singly-linked list * * This library provides functions for the creation and manipulation of * circular, singly-linked lists. * * A circular, singly-linked list is declared using the CIRCULAR_LIST macro. * Elements must be allocated by the calling code and must be of a C struct * datatype. In this struct, the first field must be a pointer called \e next. * This field will be used by the library to maintain the list. Application * code must not modify this field directly. * * Functions that modify the list (add / remove) will, in the general case, * update the list's head and item order. If you call one of these functions * as part of a list traversal, it is advised to stop / restart traversing * after the respective function returns. * @{ */ /*---------------------------------------------------------------------------*/ #ifndef CIRCULAR_LIST_H_ #define CIRCULAR_LIST_H_ /*---------------------------------------------------------------------------*/ #include "contiki.h" #include #include #include /*---------------------------------------------------------------------------*/ /** * \brief Define a circular, singly-linked list. * * This macro defines a circular, singly-linked list. * * The datatype for elements must be a C struct. The struct's first member must * be a pointer called \e next. This is used internally by the library to * maintain data structure integrity and must not be modified directly by * application code. * * \param name The name of the circular, singly-linked list. */ #define CIRCULAR_LIST(name) \ static void *name##_circular_list = NULL; \ static circular_list_t name = (circular_list_t)&name##_circular_list /*---------------------------------------------------------------------------*/ /** * \brief The circular, singly-linked list datatype */ typedef void **circular_list_t; /*---------------------------------------------------------------------------*/ /** * \brief Initialise a circular, singly-linked list. * \param cl The circular, singly-linked list. */ void circular_list_init(circular_list_t cl); /** * \brief Return the tail of a circular, singly-linked list. * \param cl The circular, singly-linked list. * \return A pointer to the list's head, or NULL if the list is empty */ void *circular_list_head(circular_list_t cl); /** * \brief Return the tail of a circular, singly-linked list. * \param cl The circular, singly-linked list. * \return A pointer to the list's tail, or NULL if the list is empty */ void *circular_list_tail(circular_list_t cl); /** * \brief Add an element to a circular, singly-linked list. * \param cl The circular, singly-linked list. * \param element A pointer to the element to be added. * * The caller should make no assumptions as to the position in the list of the * new element. * * After this function returns, the list's head is not guaranteed to be the * same as it was before the addition. * * Calling this function will update the list's head and item order. If you * call this function as part of a list traversal, it is advised to stop * traversing after this function returns. */ void circular_list_add(circular_list_t cl, void *element); /** * \brief Remove an element from a circular, singly-linked list. * \param cl The circular, singly-linked list. * \param element A pointer to the element to be removed. * * After this function returns, the list's head is not guaranteed to be the * same as it was before the addition. * * Calling this function will update the list's head and item order. If you * call this function as part of a list traversal, it is advised to stop * traversing after this function returns. */ void circular_list_remove(circular_list_t cl, void *element); /** * \brief Get the length of a circular, singly-linked list. * \param cl The circular, singly-linked list. * \return The number of elements in the list */ unsigned long circular_list_length(circular_list_t cl); /** * \brief Determine whether a circular, singly-linked list is empty. * \param cl The circular, singly-linked list. * \retval true The list is empty * \retval false The list is not empty */ bool circular_list_is_empty(circular_list_t cl); /*---------------------------------------------------------------------------*/ #endif /* CIRCULAR_LIST_H_ */ /*---------------------------------------------------------------------------*/ /** * @} * @} */