/* | |
FreeRTOS V5.4.2 - Copyright (C) 2009 Real Time Engineers Ltd. | |
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. | |
Alternative commercial license and support terms are also available upon | |
request. See the licensing section of http://www.FreeRTOS.org for full | |
license details. | |
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 along | |
with FreeRTOS; if not, write to the Free Software Foundation, Inc., 59 | |
Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
*************************************************************************** | |
* * | |
* Looking for a quick start? Then check out the FreeRTOS eBook! * | |
* See http://www.FreeRTOS.org/Documentation for details * | |
* * | |
*************************************************************************** | |
1 tab == 4 spaces! | |
Please ensure to read the configuration and relevant port sections of the | |
online documentation. | |
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 = 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 )--; | |
} | |
/*-----------------------------------------------------------*/ | |