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Diffstat (limited to 'FreeRTOS/Source/include/list.h')
| -rw-r--r-- | FreeRTOS/Source/include/list.h | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/FreeRTOS/Source/include/list.h b/FreeRTOS/Source/include/list.h new file mode 100644 index 0000000..5a09fd1 --- /dev/null +++ b/FreeRTOS/Source/include/list.h @@ -0,0 +1,305 @@ +/*
+ FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
+
+ ***************************************************************************
+ * *
+ * If you are: *
+ * *
+ * + New to FreeRTOS, *
+ * + Wanting to learn FreeRTOS or multitasking in general quickly *
+ * + Looking for basic training, *
+ * + Wanting to improve your FreeRTOS skills and productivity *
+ * *
+ * then take a look at the FreeRTOS books - available as PDF or paperback *
+ * *
+ * "Using the FreeRTOS Real Time Kernel - a Practical Guide" *
+ * http://www.FreeRTOS.org/Documentation *
+ * *
+ * A pdf reference manual is also available. Both are usually delivered *
+ * to your inbox within 20 minutes to two hours when purchased between 8am *
+ * and 8pm GMT (although please allow up to 24 hours in case of *
+ * exceptional circumstances). 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 exception 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
+ */
+
+/*
+ Changes from V4.3.1
+
+ + Included local const within listGET_OWNER_OF_NEXT_ENTRY() to assist
+ compiler with optimisation. Thanks B.R.
+*/
+
+#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 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->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 );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
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