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Diffstat (limited to 'libraries/FreeRTOS/utility/list.h')
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diff --git a/libraries/FreeRTOS/utility/list.h b/libraries/FreeRTOS/utility/list.h new file mode 100755 index 0000000..01e69cb --- /dev/null +++ b/libraries/FreeRTOS/utility/list.h @@ -0,0 +1,314 @@ +/* + FreeRTOS V7.0.1 - Copyright (C) 2011 Real Time Engineers Ltd. + + + FreeRTOS supports many tools and architectures. V7.0.0 is sponsored by: + Atollic AB - Atollic provides professional embedded systems development + tools for C/C++ development, code analysis and test automation. + See http://www.atollic.com + + + *************************************************************************** + * * + * FreeRTOS tutorial books are available in pdf and paperback. * + * Complete, revised, and edited pdf reference manuals are also * + * available. * + * * + * Purchasing FreeRTOS documentation will not only help you, by * + * ensuring you get running as quickly as possible and with an * + * in-depth knowledge of how to use FreeRTOS, it will also help * + * the FreeRTOS project to continue with its mission of providing * + * professional grade, cross platform, de facto standard solutions * + * for microcontrollers - completely free of charge! * + * * + * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * + * * + * Thank you for using FreeRTOS, and thank you for your support! * + * * + *************************************************************************** + + + This file is part of the FreeRTOS distribution. + + FreeRTOS is free software; you can redistribute it and/or modify it under + the terms of the GNU General Public License (version 2) as published by the + Free Software Foundation AND MODIFIED BY the FreeRTOS exception. + >>>NOTE<<< The modification to the GPL is included to allow you to + distribute a combined work that includes FreeRTOS without being obliged to + provide the source code for proprietary components outside of the FreeRTOS + kernel. FreeRTOS is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + more details. You should have received a copy of the GNU General Public + License and the FreeRTOS license exception along with FreeRTOS; if not it + can be viewed here: http://www.freertos.org/a00114.html and also obtained + by writing to Richard Barry, contact details for whom are available on the + FreeRTOS WEB site. + + 1 tab == 4 spaces! + + http://www.FreeRTOS.org - Documentation, latest information, license and + contact details. + + http://www.SafeRTOS.com - A version that is certified for use in safety + critical systems. + + http://www.OpenRTOS.com - Commercial support, development, porting, + licensing and training services. +*/ + +/* + * This is the list implementation used by the scheduler. While it is tailored + * heavily for the schedulers needs, it is also available for use by + * application code. + * + * xLists can only store pointers to xListItems. Each xListItem contains a + * numeric value (xItemValue). Most of the time the lists are sorted in + * descending item value order. + * + * Lists are created already containing one list item. The value of this + * item is the maximum possible that can be stored, it is therefore always at + * the end of the list and acts as a marker. The list member pxHead always + * points to this marker - even though it is at the tail of the list. This + * is because the tail contains a wrap back pointer to the true head of + * the list. + * + * In addition to it's value, each list item contains a pointer to the next + * item in the list (pxNext), a pointer to the list it is in (pxContainer) + * and a pointer to back to the object that contains it. These later two + * pointers are included for efficiency of list manipulation. There is + * effectively a two way link between the object containing the list item and + * the list item itself. + * + * + * \page ListIntroduction List Implementation + * \ingroup FreeRTOSIntro + */ + + +#ifndef LIST_H +#define LIST_H + +#ifdef __cplusplus +extern "C" { +#endif +/* + * Definition of the only type of object that a list can contain. + */ +struct xLIST_ITEM +{ + portTickType xItemValue; /*< The value being listed. In most cases this is used to sort the list in descending order. */ + volatile struct xLIST_ITEM * pxNext; /*< Pointer to the next xListItem in the list. */ + volatile struct xLIST_ITEM * pxPrevious;/*< Pointer to the previous xListItem in the list. */ + void * pvOwner; /*< Pointer to the object (normally a TCB) that contains the list item. There is therefore a two way link between the object containing the list item and the list item itself. */ + void * pvContainer; /*< Pointer to the list in which this list item is placed (if any). */ +}; +typedef struct xLIST_ITEM xListItem; /* For some reason lint wants this as two separate definitions. */ + +struct xMINI_LIST_ITEM +{ + portTickType xItemValue; + volatile struct xLIST_ITEM *pxNext; + volatile struct xLIST_ITEM *pxPrevious; +}; +typedef struct xMINI_LIST_ITEM xMiniListItem; + +/* + * Definition of the type of queue used by the scheduler. + */ +typedef struct xLIST +{ + volatile unsigned portBASE_TYPE uxNumberOfItems; + volatile xListItem * pxIndex; /*< Used to walk through the list. Points to the last item returned by a call to pvListGetOwnerOfNextEntry (). */ + volatile xMiniListItem xListEnd; /*< List item that contains the maximum possible item value meaning it is always at the end of the list and is therefore used as a marker. */ +} xList; + +/* + * Access macro to set the owner of a list item. The owner of a list item + * is the object (usually a TCB) that contains the list item. + * + * \page listSET_LIST_ITEM_OWNER listSET_LIST_ITEM_OWNER + * \ingroup LinkedList + */ +#define listSET_LIST_ITEM_OWNER( pxListItem, pxOwner ) ( pxListItem )->pvOwner = ( void * ) ( pxOwner ) + +/* + * Access macro to set the value of the list item. In most cases the value is + * used to sort the list in descending order. + * + * \page listSET_LIST_ITEM_VALUE listSET_LIST_ITEM_VALUE + * \ingroup LinkedList + */ +#define listSET_LIST_ITEM_VALUE( pxListItem, xValue ) ( pxListItem )->xItemValue = ( xValue ) + +/* + * Access macro the retrieve the value of the list item. The value can + * represent anything - for example a the priority of a task, or the time at + * which a task should be unblocked. + * + * \page listGET_LIST_ITEM_VALUE listGET_LIST_ITEM_VALUE + * \ingroup LinkedList + */ +#define listGET_LIST_ITEM_VALUE( pxListItem ) ( ( pxListItem )->xItemValue ) + +/* + * Access macro the retrieve the value of the list item at the head of a given + * list. + * + * \page listGET_LIST_ITEM_VALUE listGET_LIST_ITEM_VALUE + * \ingroup LinkedList + */ +#define listGET_ITEM_VALUE_OF_HEAD_ENTRY( pxList ) ( (&( ( pxList )->xListEnd ))->pxNext->xItemValue ) + +/* + * Access macro to determine if a list contains any items. The macro will + * only have the value true if the list is empty. + * + * \page listLIST_IS_EMPTY listLIST_IS_EMPTY + * \ingroup LinkedList + */ +#define listLIST_IS_EMPTY( pxList ) ( ( pxList )->uxNumberOfItems == ( unsigned portBASE_TYPE ) 0 ) + +/* + * Access macro to return the number of items in the list. + */ +#define listCURRENT_LIST_LENGTH( pxList ) ( ( pxList )->uxNumberOfItems ) + +/* + * Access function to obtain the owner of the next entry in a list. + * + * The list member pxIndex is used to walk through a list. Calling + * listGET_OWNER_OF_NEXT_ENTRY increments pxIndex to the next item in the list + * and returns that entries pxOwner parameter. Using multiple calls to this + * function it is therefore possible to move through every item contained in + * a list. + * + * The pxOwner parameter of a list item is a pointer to the object that owns + * the list item. In the scheduler this is normally a task control block. + * The pxOwner parameter effectively creates a two way link between the list + * item and its owner. + * + * @param pxList The list from which the next item owner is to be returned. + * + * \page listGET_OWNER_OF_NEXT_ENTRY listGET_OWNER_OF_NEXT_ENTRY + * \ingroup LinkedList + */ +#define listGET_OWNER_OF_NEXT_ENTRY( pxTCB, pxList ) \ +{ \ +xList * const pxConstList = ( pxList ); \ + /* Increment the index to the next item and return the item, ensuring */ \ + /* we don't return the marker used at the end of the list. */ \ + ( pxConstList )->pxIndex = ( pxConstList )->pxIndex->pxNext; \ + if( ( pxConstList )->pxIndex == ( xListItem * ) &( ( pxConstList )->xListEnd ) ) \ + { \ + ( pxConstList )->pxIndex = ( pxConstList )->pxIndex->pxNext; \ + } \ + ( pxTCB ) = ( pxConstList )->pxIndex->pvOwner; \ +} + + +/* + * Access function to obtain the owner of the first entry in a list. Lists + * are normally sorted in ascending item value order. + * + * This function returns the pxOwner member of the first item in the list. + * The pxOwner parameter of a list item is a pointer to the object that owns + * the list item. In the scheduler this is normally a task control block. + * The pxOwner parameter effectively creates a two way link between the list + * item and its owner. + * + * @param pxList The list from which the owner of the head item is to be + * returned. + * + * \page listGET_OWNER_OF_HEAD_ENTRY listGET_OWNER_OF_HEAD_ENTRY + * \ingroup LinkedList + */ +#define listGET_OWNER_OF_HEAD_ENTRY( pxList ) ( (&( ( pxList )->xListEnd ))->pxNext->pvOwner ) + +/* + * Check to see if a list item is within a list. The list item maintains a + * "container" pointer that points to the list it is in. All this macro does + * is check to see if the container and the list match. + * + * @param pxList The list we want to know if the list item is within. + * @param pxListItem The list item we want to know if is in the list. + * @return pdTRUE is the list item is in the list, otherwise pdFALSE. + * pointer against + */ +#define listIS_CONTAINED_WITHIN( pxList, pxListItem ) ( ( pxListItem )->pvContainer == ( void * ) ( pxList ) ) + +/* + * Must be called before a list is used! This initialises all the members + * of the list structure and inserts the xListEnd item into the list as a + * marker to the back of the list. + * + * @param pxList Pointer to the list being initialised. + * + * \page vListInitialise vListInitialise + * \ingroup LinkedList + */ +void vListInitialise( xList *pxList ); + +/* + * Must be called before a list item is used. This sets the list container to + * null so the item does not think that it is already contained in a list. + * + * @param pxItem Pointer to the list item being initialised. + * + * \page vListInitialiseItem vListInitialiseItem + * \ingroup LinkedList + */ +void vListInitialiseItem( xListItem *pxItem ); + +/* + * Insert a list item into a list. The item will be inserted into the list in + * a position determined by its item value (descending item value order). + * + * @param pxList The list into which the item is to be inserted. + * + * @param pxNewListItem The item to that is to be placed in the list. + * + * \page vListInsert vListInsert + * \ingroup LinkedList + */ +void vListInsert( xList *pxList, xListItem *pxNewListItem ); + +/* + * Insert a list item into a list. The item will be inserted in a position + * such that it will be the last item within the list returned by multiple + * calls to listGET_OWNER_OF_NEXT_ENTRY. + * + * The list member pvIndex is used to walk through a list. Calling + * listGET_OWNER_OF_NEXT_ENTRY increments pvIndex to the next item in the list. + * Placing an item in a list using vListInsertEnd effectively places the item + * in the list position pointed to by pvIndex. This means that every other + * item within the list will be returned by listGET_OWNER_OF_NEXT_ENTRY before + * the pvIndex parameter again points to the item being inserted. + * + * @param pxList The list into which the item is to be inserted. + * + * @param pxNewListItem The list item to be inserted into the list. + * + * \page vListInsertEnd vListInsertEnd + * \ingroup LinkedList + */ +void vListInsertEnd( xList *pxList, xListItem *pxNewListItem ); + +/* + * Remove an item from a list. The list item has a pointer to the list that + * it is in, so only the list item need be passed into the function. + * + * @param vListRemove The item to be removed. The item will remove itself from + * the list pointed to by it's pxContainer parameter. + * + * \page vListRemove vListRemove + * \ingroup LinkedList + */ +void vListRemove( xListItem *pxItemToRemove ); + +#ifdef __cplusplus +} +#endif + +#endif + |