FreeRTOS/Source/list.c - third_party/github/FreeRTOS/FreeRTOS-Kernel - Git at Google

 /*
  * FreeRTOS Kernel V10.3.0
  * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
  * the Software without restriction, including without limitation the rights to
  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
  * the Software, and to permit persons to whom the Software is furnished to do so,
  * subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in all
  * copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  *
  * http://www.FreeRTOS.org
  * http://aws.amazon.com/freertos
  *
  * 1 tab == 4 spaces!
  */


 #include <stdlib.h>
 #include "FreeRTOS.h"
 #include "list.h"

 /*-----------------------------------------------------------
  * PUBLIC LIST API documented in list.h
  *----------------------------------------------------------*/

 void vListInitialise( List_t * const 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 = ( ListItem_t * ) &( pxList->xListEnd );			/*lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM.  This is checked and valid. */

 	/* 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 = ( ListItem_t * ) &( pxList->xListEnd );	/*lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM.  This is checked and valid. */
 	pxList->xListEnd.pxPrevious = ( ListItem_t * ) &( pxList->xListEnd );/*lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM.  This is checked and valid. */

 	pxList->uxNumberOfItems = ( UBaseType_t ) 0U;

 	/* Write known values into the list if
 	configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES is set to 1. */
 	listSET_LIST_INTEGRITY_CHECK_1_VALUE( pxList );
 	listSET_LIST_INTEGRITY_CHECK_2_VALUE( pxList );
 }
 /*-----------------------------------------------------------*/

 void vListInitialiseItem( ListItem_t * const pxItem )
 {
 	/* Make sure the list item is not recorded as being on a list. */
 	pxItem->pxContainer = NULL;

 	/* Write known values into the list item if
 	configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES is set to 1. */
 	listSET_FIRST_LIST_ITEM_INTEGRITY_CHECK_VALUE( pxItem );
 	listSET_SECOND_LIST_ITEM_INTEGRITY_CHECK_VALUE( pxItem );
 }
 /*-----------------------------------------------------------*/

 void vListInsertEnd( List_t * const pxList, ListItem_t * const pxNewListItem )
 {
 ListItem_t * const pxIndex = pxList->pxIndex;

 	/* Only effective when configASSERT() is also defined, these tests may catch
 	the list data structures being overwritten in memory.  They will not catch
 	data errors caused by incorrect configuration or use of FreeRTOS. */
 	listTEST_LIST_INTEGRITY( pxList );
 	listTEST_LIST_ITEM_INTEGRITY( pxNewListItem );

 	/* 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
 	listGET_OWNER_OF_NEXT_ENTRY(). */
 	pxNewListItem->pxNext = pxIndex;
 	pxNewListItem->pxPrevious = pxIndex->pxPrevious;

 	/* Only used during decision coverage testing. */
 	mtCOVERAGE_TEST_DELAY();

 	pxIndex->pxPrevious->pxNext = pxNewListItem;
 	pxIndex->pxPrevious = pxNewListItem;

 	/* Remember which list the item is in. */
 	pxNewListItem->pxContainer = pxList;

 	( pxList->uxNumberOfItems )++;
 }
 /*-----------------------------------------------------------*/

 void vListInsert( List_t * const pxList, ListItem_t * const pxNewListItem )
 {
 ListItem_t *pxIterator;
 const TickType_t xValueOfInsertion = pxNewListItem->xItemValue;

 	/* Only effective when configASSERT() is also defined, these tests may catch
 	the list data structures being overwritten in memory.  They will not catch
 	data errors caused by incorrect configuration or use of FreeRTOS. */
 	listTEST_LIST_INTEGRITY( pxList );
 	listTEST_LIST_ITEM_INTEGRITY( pxNewListItem );

 	/* Insert the new list item into the list, sorted in xItemValue order.

 	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 TCBs which are
 	stored in ready lists (all of which have the same xItemValue value) get a
 	share of the CPU.  However, if the xItemValue is the same as the back marker
 	the iteration loop below will not end.  Therefore the value is checked
 	first, and the algorithm slightly modified if necessary. */
 	if( xValueOfInsertion == portMAX_DELAY )
 	{
 		pxIterator = pxList->xListEnd.pxPrevious;
 	}
 	else
 	{
 		/* *** NOTE ***********************************************************
 		If you find your application is crashing here then likely causes are
 		listed below.  In addition see https://www.freertos.org/FAQHelp.html for
 		more tips, and ensure configASSERT() is defined!
 		https://www.freertos.org/a00110.html#configASSERT

 			1) Stack overflow -
 			   see https://www.freertos.org/Stacks-and-stack-overflow-checking.html
 			2) Incorrect interrupt priority assignment, especially on Cortex-M
 			   parts where numerically high priority values denote low actual
 			   interrupt priorities, which can seem counter intuitive.  See
 			   https://www.freertos.org/RTOS-Cortex-M3-M4.html and the definition
 			   of configMAX_SYSCALL_INTERRUPT_PRIORITY on
 			   https://www.freertos.org/a00110.html
 			3) Calling an API function from within a critical section or when
 			   the scheduler is suspended, or calling an API function that does
 			   not end in "FromISR" from an interrupt.
 			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?).
 		**********************************************************************/

 		for( pxIterator = ( ListItem_t * ) &( pxList->xListEnd ); pxIterator->pxNext->xItemValue <= xValueOfInsertion; pxIterator = pxIterator->pxNext ) /*lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM.  This is checked and valid. *//*lint !e440 The iterator moves to a different value, not xValueOfInsertion. */
 		{
 			/* There is nothing to do here, just iterating to the wanted
 			insertion position. */
 		}
 	}

 	pxNewListItem->pxNext = pxIterator->pxNext;
 	pxNewListItem->pxNext->pxPrevious = pxNewListItem;
 	pxNewListItem->pxPrevious = pxIterator;
 	pxIterator->pxNext = pxNewListItem;

 	/* Remember which list the item is in.  This allows fast removal of the
 	item later. */
 	pxNewListItem->pxContainer = pxList;

 	( pxList->uxNumberOfItems )++;
 }
 /*-----------------------------------------------------------*/

 UBaseType_t uxListRemove( ListItem_t * const pxItemToRemove )
 {
 /* The list item knows which list it is in.  Obtain the list from the list
 item. */
 List_t * const pxList = pxItemToRemove->pxContainer;

 	pxItemToRemove->pxNext->pxPrevious = pxItemToRemove->pxPrevious;
 	pxItemToRemove->pxPrevious->pxNext = pxItemToRemove->pxNext;

 	/* Only used during decision coverage testing. */
 	mtCOVERAGE_TEST_DELAY();

 	/* Make sure the index is left pointing to a valid item. */
 	if( pxList->pxIndex == pxItemToRemove )
 	{
 		pxList->pxIndex = pxItemToRemove->pxPrevious;
 	}
 	else
 	{
 		mtCOVERAGE_TEST_MARKER();
 	}

 	pxItemToRemove->pxContainer = NULL;
 	( pxList->uxNumberOfItems )--;

 	return pxList->uxNumberOfItems;
 }
 /*-----------------------------------------------------------*/
	/*
	* FreeRTOS Kernel V10.3.0
	* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy of
	* this software and associated documentation files (the "Software"), to deal in
	* the Software without restriction, including without limitation the rights to
	* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
	* the Software, and to permit persons to whom the Software is furnished to do so,
	* subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in all
	* copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
	* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
	* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
	* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*
	* http://www.FreeRTOS.org
	* http://aws.amazon.com/freertos
	*
	* 1 tab == 4 spaces!
	*/


	#include <stdlib.h>
	#include "FreeRTOS.h"
	#include "list.h"

	/*-----------------------------------------------------------
	* PUBLIC LIST API documented in list.h
	----------------------------------------------------------/

	void vListInitialise( List_t * const 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 = ( ListItem_t * ) &( pxList->xListEnd ); /lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM. This is checked and valid. /

	/* 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 = ( ListItem_t * ) &( pxList->xListEnd ); /lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM. This is checked and valid. /
	pxList->xListEnd.pxPrevious = ( ListItem_t * ) &( pxList->xListEnd );/lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM. This is checked and valid. /

	pxList->uxNumberOfItems = ( UBaseType_t ) 0U;

	/* Write known values into the list if
	configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES is set to 1. */
	listSET_LIST_INTEGRITY_CHECK_1_VALUE( pxList );
	listSET_LIST_INTEGRITY_CHECK_2_VALUE( pxList );
	}
	/-----------------------------------------------------------/

	void vListInitialiseItem( ListItem_t * const pxItem )
	{
	/* Make sure the list item is not recorded as being on a list. */
	pxItem->pxContainer = NULL;

	/* Write known values into the list item if
	configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES is set to 1. */
	listSET_FIRST_LIST_ITEM_INTEGRITY_CHECK_VALUE( pxItem );
	listSET_SECOND_LIST_ITEM_INTEGRITY_CHECK_VALUE( pxItem );
	}
	/-----------------------------------------------------------/

	void vListInsertEnd( List_t * const pxList, ListItem_t * const pxNewListItem )
	{
	ListItem_t * const pxIndex = pxList->pxIndex;

	/* Only effective when configASSERT() is also defined, these tests may catch
	the list data structures being overwritten in memory. They will not catch
	data errors caused by incorrect configuration or use of FreeRTOS. */
	listTEST_LIST_INTEGRITY( pxList );
	listTEST_LIST_ITEM_INTEGRITY( pxNewListItem );

	/* 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
	listGET_OWNER_OF_NEXT_ENTRY(). */
	pxNewListItem->pxNext = pxIndex;
	pxNewListItem->pxPrevious = pxIndex->pxPrevious;

	/* Only used during decision coverage testing. */
	mtCOVERAGE_TEST_DELAY();

	pxIndex->pxPrevious->pxNext = pxNewListItem;
	pxIndex->pxPrevious = pxNewListItem;

	/* Remember which list the item is in. */
	pxNewListItem->pxContainer = pxList;

	( pxList->uxNumberOfItems )++;
	}
	/-----------------------------------------------------------/

	void vListInsert( List_t * const pxList, ListItem_t * const pxNewListItem )
	{
	ListItem_t *pxIterator;
	const TickType_t xValueOfInsertion = pxNewListItem->xItemValue;

	/* Only effective when configASSERT() is also defined, these tests may catch
	the list data structures being overwritten in memory. They will not catch
	data errors caused by incorrect configuration or use of FreeRTOS. */
	listTEST_LIST_INTEGRITY( pxList );
	listTEST_LIST_ITEM_INTEGRITY( pxNewListItem );

	/* Insert the new list item into the list, sorted in xItemValue order.

	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 TCBs which are
	stored in ready lists (all of which have the same xItemValue value) get a
	share of the CPU. However, if the xItemValue is the same as the back marker
	the iteration loop below will not end. Therefore the value is checked
	first, and the algorithm slightly modified if necessary. */
	if( xValueOfInsertion == portMAX_DELAY )
	{
	pxIterator = pxList->xListEnd.pxPrevious;
	}
	else
	{
	/* * NOTE *********************************************************
	If you find your application is crashing here then likely causes are
	listed below. In addition see https://www.freertos.org/FAQHelp.html for
	more tips, and ensure configASSERT() is defined!
	https://www.freertos.org/a00110.html#configASSERT

	1) Stack overflow -
	see https://www.freertos.org/Stacks-and-stack-overflow-checking.html
	2) Incorrect interrupt priority assignment, especially on Cortex-M
	parts where numerically high priority values denote low actual
	interrupt priorities, which can seem counter intuitive. See
	https://www.freertos.org/RTOS-Cortex-M3-M4.html and the definition
	of configMAX_SYSCALL_INTERRUPT_PRIORITY on
	https://www.freertos.org/a00110.html
	3) Calling an API function from within a critical section or when
	the scheduler is suspended, or calling an API function that does
	not end in "FromISR" from an interrupt.
	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?).
	**********************************************************************/

	for( pxIterator = ( ListItem_t * ) &( pxList->xListEnd ); pxIterator->pxNext->xItemValue <= xValueOfInsertion; pxIterator = pxIterator->pxNext ) /lint !e826 !e740 !e9087 The mini list structure is used as the list end to save RAM. This is checked and valid. //lint !e440 The iterator moves to a different value, not xValueOfInsertion. /
	{
	/* There is nothing to do here, just iterating to the wanted
	insertion position. */
	}
	}

	pxNewListItem->pxNext = pxIterator->pxNext;
	pxNewListItem->pxNext->pxPrevious = pxNewListItem;
	pxNewListItem->pxPrevious = pxIterator;
	pxIterator->pxNext = pxNewListItem;

	/* Remember which list the item is in. This allows fast removal of the
	item later. */
	pxNewListItem->pxContainer = pxList;

	( pxList->uxNumberOfItems )++;
	}
	/-----------------------------------------------------------/

	UBaseType_t uxListRemove( ListItem_t * const pxItemToRemove )
	{
	/* The list item knows which list it is in. Obtain the list from the list
	item. */
	List_t * const pxList = pxItemToRemove->pxContainer;

	pxItemToRemove->pxNext->pxPrevious = pxItemToRemove->pxPrevious;
	pxItemToRemove->pxPrevious->pxNext = pxItemToRemove->pxNext;

	/* Only used during decision coverage testing. */
	mtCOVERAGE_TEST_DELAY();

	/* Make sure the index is left pointing to a valid item. */
	if( pxList->pxIndex == pxItemToRemove )
	{
	pxList->pxIndex = pxItemToRemove->pxPrevious;
	}
	else
	{
	mtCOVERAGE_TEST_MARKER();
	}

	pxItemToRemove->pxContainer = NULL;
	( pxList->uxNumberOfItems )--;

	return pxList->uxNumberOfItems;
	}
	/-----------------------------------------------------------/