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Diffstat (limited to 'openpicc/os/core/include/list.h')
| -rw-r--r-- | openpicc/os/core/include/list.h | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/openpicc/os/core/include/list.h b/openpicc/os/core/include/list.h new file mode 100644 index 0000000..cdd6a75 --- /dev/null +++ b/openpicc/os/core/include/list.h @@ -0,0 +1,272 @@ +/* + FreeRTOS.org V4.2.1 - Copyright (C) 2003-2007 Richard Barry. + + This file is part of the FreeRTOS.org distribution. + + FreeRTOS.org is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + FreeRTOS.org 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 + along with FreeRTOS.org; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + + A special exception to the GPL can be applied should you wish to distribute + a combined work that includes FreeRTOS.org, without being obliged to provide + the source code for any proprietary components. See the licensing section + of http://www.FreeRTOS.org for full details of how and when the exception + can be applied. + + *************************************************************************** + See http://www.FreeRTOS.org for documentation, latest information, license + and contact details. Please ensure to read the configuration and relevant + port sections of the online documentation. + + Also see http://www.SafeRTOS.com for an IEC 61508 compliant version along + with commercial development and support options. + *************************************************************************** +*/ + +/* + * 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 + +/* + * 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 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 ) \ + /* 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. */ \ + ( pxList )->pxIndex = ( pxList )->pxIndex->pxNext; \ + if( ( pxList )->pxIndex == ( xListItem * ) &( ( pxList )->xListEnd ) ) \ + { \ + ( pxList )->pxIndex = ( pxList )->pxIndex->pxNext; \ + } \ + pxTCB = ( pxList )->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->uxNumberOfItems != ( unsigned portBASE_TYPE ) 0 ) ? ( (&( pxList->xListEnd ))->pxNext->pvOwner ) : ( NULL ) ) + +/* + * 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); + + + +#endif |