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Diffstat (limited to 'libraries/FreeRTOS/utility/list.c')
| -rwxr-xr-x | libraries/FreeRTOS/utility/list.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/libraries/FreeRTOS/utility/list.c b/libraries/FreeRTOS/utility/list.c new file mode 100755 index 0000000..872b7dd --- /dev/null +++ b/libraries/FreeRTOS/utility/list.c @@ -0,0 +1,197 @@ +/* + 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. +*/ + + +#include <stdlib.h> +#include "FreeRTOS.h" +#include "list.h" + +/*----------------------------------------------------------- + * PUBLIC LIST API documented in list.h + *----------------------------------------------------------*/ + +void vListInitialise( xList *pxList ) +{ + /* The list structure contains a list item which is used to mark the + end of the list. To initialise the list the list end is inserted + as the only list entry. */ + pxList->pxIndex = ( xListItem * ) &( pxList->xListEnd ); + + /* The list end value is the highest possible value in the list to + ensure it remains at the end of the list. */ + pxList->xListEnd.xItemValue = portMAX_DELAY; + + /* The list end next and previous pointers point to itself so we know + when the list is empty. */ + pxList->xListEnd.pxNext = ( xListItem * ) &( pxList->xListEnd ); + pxList->xListEnd.pxPrevious = ( xListItem * ) &( pxList->xListEnd ); + + pxList->uxNumberOfItems = ( unsigned portBASE_TYPE ) 0U; +} +/*-----------------------------------------------------------*/ + +void vListInitialiseItem( xListItem *pxItem ) +{ + /* Make sure the list item is not recorded as being on a list. */ + pxItem->pvContainer = NULL; +} +/*-----------------------------------------------------------*/ + +void vListInsertEnd( xList *pxList, xListItem *pxNewListItem ) +{ +volatile xListItem * pxIndex; + + /* Insert a new list item into pxList, but rather than sort the list, + makes the new list item the last item to be removed by a call to + pvListGetOwnerOfNextEntry. This means it has to be the item pointed to by + the pxIndex member. */ + pxIndex = pxList->pxIndex; + + pxNewListItem->pxNext = pxIndex->pxNext; + pxNewListItem->pxPrevious = pxList->pxIndex; + pxIndex->pxNext->pxPrevious = ( volatile xListItem * ) pxNewListItem; + pxIndex->pxNext = ( volatile xListItem * ) pxNewListItem; + pxList->pxIndex = ( volatile xListItem * ) pxNewListItem; + + /* Remember which list the item is in. */ + pxNewListItem->pvContainer = ( void * ) pxList; + + ( pxList->uxNumberOfItems )++; +} +/*-----------------------------------------------------------*/ + +void vListInsert( xList *pxList, xListItem *pxNewListItem ) +{ +volatile xListItem *pxIterator; +portTickType xValueOfInsertion; + + /* Insert the new list item into the list, sorted in ulListItem order. */ + xValueOfInsertion = pxNewListItem->xItemValue; + + /* If the list already contains a list item with the same item value then + the new list item should be placed after it. This ensures that TCB's which + are stored in ready lists (all of which have the same ulListItem value) + get an equal share of the CPU. However, if the xItemValue is the same as + the back marker the iteration loop below will not end. This means we need + to guard against this by checking the value first and modifying the + algorithm slightly if necessary. */ + if( xValueOfInsertion == portMAX_DELAY ) + { + pxIterator = pxList->xListEnd.pxPrevious; + } + else + { + /* *** NOTE *********************************************************** + If you find your application is crashing here then likely causes are: + 1) Stack overflow - + see http://www.freertos.org/Stacks-and-stack-overflow-checking.html + 2) Incorrect interrupt priority assignment, especially on Cortex-M3 + parts where numerically high priority values denote low actual + interrupt priories, which can seem counter intuitive. See + configMAX_SYSCALL_INTERRUPT_PRIORITY on http://www.freertos.org/a00110.html + 3) Calling an API function from within a critical section or when + the scheduler is suspended. + 4) Using a queue or semaphore before it has been initialised or + before the scheduler has been started (are interrupts firing + before vTaskStartScheduler() has been called?). + See http://www.freertos.org/FAQHelp.html for more tips. + **********************************************************************/ + + for( pxIterator = ( xListItem * ) &( pxList->xListEnd ); pxIterator->pxNext->xItemValue <= xValueOfInsertion; pxIterator = pxIterator->pxNext ) + { + /* There is nothing to do here, we are just iterating to the + wanted insertion position. */ + } + } + + pxNewListItem->pxNext = pxIterator->pxNext; + pxNewListItem->pxNext->pxPrevious = ( volatile xListItem * ) pxNewListItem; + pxNewListItem->pxPrevious = pxIterator; + pxIterator->pxNext = ( volatile xListItem * ) pxNewListItem; + + /* Remember which list the item is in. This allows fast removal of the + item later. */ + pxNewListItem->pvContainer = ( void * ) pxList; + + ( pxList->uxNumberOfItems )++; +} +/*-----------------------------------------------------------*/ + +void vListRemove( xListItem *pxItemToRemove ) +{ +xList * pxList; + + pxItemToRemove->pxNext->pxPrevious = pxItemToRemove->pxPrevious; + pxItemToRemove->pxPrevious->pxNext = pxItemToRemove->pxNext; + + /* The list item knows which list it is in. Obtain the list from the list + item. */ + pxList = ( xList * ) pxItemToRemove->pvContainer; + + /* Make sure the index is left pointing to a valid item. */ + if( pxList->pxIndex == pxItemToRemove ) + { + pxList->pxIndex = pxItemToRemove->pxPrevious; + } + + pxItemToRemove->pvContainer = NULL; + ( pxList->uxNumberOfItems )--; +} +/*-----------------------------------------------------------*/ + |