From d291e583a5ee10f13b0f4039a8d114e15799eb7b Mon Sep 17 00:00:00 2001 From: Pixel Date: Sun, 23 Jan 2011 12:15:10 -0800 Subject: Adding basic FreeRTOS sourcetree; v6.1.1 currently. --- FreeRTOS/Source/list.c | 191 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 191 insertions(+) create mode 100644 FreeRTOS/Source/list.c (limited to 'FreeRTOS/Source/list.c') diff --git a/FreeRTOS/Source/list.c b/FreeRTOS/Source/list.c new file mode 100644 index 0000000..a800c03 --- /dev/null +++ b/FreeRTOS/Source/list.c @@ -0,0 +1,191 @@ +/* + 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. +*/ + + +#include +#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 = 0; +} +/*-----------------------------------------------------------*/ + +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 )--; +} +/*-----------------------------------------------------------*/ + -- cgit v1.2.3