/* * FreeRTOS Kernel * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * SPDX-License-Identifier: MIT * * 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. * * https://www.FreeRTOS.org * https://github.com/FreeRTOS * */ #include /* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining * all the API functions to use the MPU wrappers. That should only be done when * task.h is included from an application file. */ #define MPU_WRAPPERS_INCLUDED_FROM_API_FILE #include "FreeRTOS.h" #include "list.h" /* The MPU ports require MPU_WRAPPERS_INCLUDED_FROM_API_FILE to be * defined for the header files above, but not in this file, in order to * generate the correct privileged Vs unprivileged linkage and placement. */ #undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE /*----------------------------------------------------------- * PUBLIC LIST API documented in list.h *----------------------------------------------------------*/ void vListInitialise( List_t * const pxList ) { traceENTER_vListInitialise( 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 ); listSET_FIRST_LIST_ITEM_INTEGRITY_CHECK_VALUE( &( 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 = ( ListItem_t * ) &( pxList->xListEnd ); pxList->xListEnd.pxPrevious = ( ListItem_t * ) &( pxList->xListEnd ); /* Initialize the remaining fields of xListEnd when it is a proper ListItem_t */ #if ( configUSE_MINI_LIST_ITEM == 0 ) { pxList->xListEnd.pvOwner = NULL; pxList->xListEnd.pxContainer = NULL; listSET_SECOND_LIST_ITEM_INTEGRITY_CHECK_VALUE( &( pxList->xListEnd ) ); } #endif 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 ); traceRETURN_vListInitialise(); } /*-----------------------------------------------------------*/ void vListInitialiseItem( ListItem_t * const pxItem ) { traceENTER_vListInitialiseItem( 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 ); traceRETURN_vListInitialiseItem(); } /*-----------------------------------------------------------*/ void vListInsertEnd( List_t * const pxList, ListItem_t * const pxNewListItem ) { ListItem_t * const pxIndex = pxList->pxIndex; traceENTER_vListInsertEnd( pxList, pxNewListItem ); /* 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 )++; traceRETURN_vListInsertEnd(); } /*-----------------------------------------------------------*/ void vListInsert( List_t * const pxList, ListItem_t * const pxNewListItem ) { ListItem_t * pxIterator; const TickType_t xValueOfInsertion = pxNewListItem->xItemValue; traceENTER_vListInsert( pxList, pxNewListItem ); /* 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?). * 5) If the FreeRTOS port supports interrupt nesting then ensure that * the priority of the tick interrupt is at or below * configMAX_SYSCALL_INTERRUPT_PRIORITY. **********************************************************************/ for( pxIterator = ( ListItem_t * ) &( pxList->xListEnd ); pxIterator->pxNext->xItemValue <= xValueOfInsertion; pxIterator = pxIterator->pxNext ) { /* 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 )++; traceRETURN_vListInsert(); } /*-----------------------------------------------------------*/ 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; traceENTER_uxListRemove( pxItemToRemove ); 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 )--; traceRETURN_uxListRemove( pxList->uxNumberOfItems ); return pxList->uxNumberOfItems; } /*-----------------------------------------------------------*/