| /* | |
| * FreeRTOS Kernel <DEVELOPMENT BRANCH> | |
| * 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 | |
| * | |
| */ | |
| /* | |
| * A sample implementation of pvPortMalloc() and vPortFree() that permits | |
| * allocated blocks to be freed, but does not combine adjacent free blocks | |
| * into a single larger block (and so will fragment memory). See heap_4.c for | |
| * an equivalent that does combine adjacent blocks into single larger blocks. | |
| * | |
| * See heap_1.c, heap_3.c and heap_4.c for alternative implementations, and the | |
| * memory management pages of https://www.FreeRTOS.org for more information. | |
| */ | |
| #include <stdlib.h> | |
| #include <string.h> | |
| /* 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 "task.h" | |
| #undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE | |
| #if ( configSUPPORT_DYNAMIC_ALLOCATION == 0 ) | |
| #error This file must not be used if configSUPPORT_DYNAMIC_ALLOCATION is 0 | |
| #endif | |
| #ifndef configHEAP_CLEAR_MEMORY_ON_FREE | |
| #define configHEAP_CLEAR_MEMORY_ON_FREE 0 | |
| #endif | |
| /* A few bytes might be lost to byte aligning the heap start address. */ | |
| #define configADJUSTED_HEAP_SIZE ( configTOTAL_HEAP_SIZE - portBYTE_ALIGNMENT ) | |
| /* Assumes 8bit bytes! */ | |
| #define heapBITS_PER_BYTE ( ( size_t ) 8 ) | |
| /* Max value that fits in a size_t type. */ | |
| #define heapSIZE_MAX ( ~( ( size_t ) 0 ) ) | |
| /* Check if multiplying a and b will result in overflow. */ | |
| #define heapMULTIPLY_WILL_OVERFLOW( a, b ) ( ( ( a ) > 0 ) && ( ( b ) > ( heapSIZE_MAX / ( a ) ) ) ) | |
| /* Check if adding a and b will result in overflow. */ | |
| #define heapADD_WILL_OVERFLOW( a, b ) ( ( a ) > ( heapSIZE_MAX - ( b ) ) ) | |
| /* MSB of the xBlockSize member of an BlockLink_t structure is used to track | |
| * the allocation status of a block. When MSB of the xBlockSize member of | |
| * an BlockLink_t structure is set then the block belongs to the application. | |
| * When the bit is free the block is still part of the free heap space. */ | |
| #define heapBLOCK_ALLOCATED_BITMASK ( ( ( size_t ) 1 ) << ( ( sizeof( size_t ) * heapBITS_PER_BYTE ) - 1 ) ) | |
| #define heapBLOCK_SIZE_IS_VALID( xBlockSize ) ( ( ( xBlockSize ) & heapBLOCK_ALLOCATED_BITMASK ) == 0 ) | |
| #define heapBLOCK_IS_ALLOCATED( pxBlock ) ( ( ( pxBlock->xBlockSize ) & heapBLOCK_ALLOCATED_BITMASK ) != 0 ) | |
| #define heapALLOCATE_BLOCK( pxBlock ) ( ( pxBlock->xBlockSize ) |= heapBLOCK_ALLOCATED_BITMASK ) | |
| #define heapFREE_BLOCK( pxBlock ) ( ( pxBlock->xBlockSize ) &= ~heapBLOCK_ALLOCATED_BITMASK ) | |
| /*-----------------------------------------------------------*/ | |
| /* Allocate the memory for the heap. */ | |
| #if ( configAPPLICATION_ALLOCATED_HEAP == 1 ) | |
| /* The application writer has already defined the array used for the RTOS | |
| * heap - probably so it can be placed in a special segment or address. */ | |
| extern uint8_t ucHeap[ configTOTAL_HEAP_SIZE ]; | |
| #else | |
| PRIVILEGED_DATA static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ]; | |
| #endif /* configAPPLICATION_ALLOCATED_HEAP */ | |
| /* Define the linked list structure. This is used to link free blocks in order | |
| * of their size. */ | |
| typedef struct A_BLOCK_LINK | |
| { | |
| struct A_BLOCK_LINK * pxNextFreeBlock; /*<< The next free block in the list. */ | |
| size_t xBlockSize; /*<< The size of the free block. */ | |
| } BlockLink_t; | |
| static const uint16_t heapSTRUCT_SIZE = ( ( sizeof( BlockLink_t ) + ( portBYTE_ALIGNMENT - 1 ) ) & ~( ( size_t ) portBYTE_ALIGNMENT_MASK ) ); | |
| #define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( heapSTRUCT_SIZE * 2 ) ) | |
| /* Create a couple of list links to mark the start and end of the list. */ | |
| PRIVILEGED_DATA static BlockLink_t xStart, xEnd; | |
| /* Keeps track of the number of free bytes remaining, but says nothing about | |
| * fragmentation. */ | |
| PRIVILEGED_DATA static size_t xFreeBytesRemaining = configADJUSTED_HEAP_SIZE; | |
| /*-----------------------------------------------------------*/ | |
| /* | |
| * Initialises the heap structures before their first use. | |
| */ | |
| static void prvHeapInit( void ) PRIVILEGED_FUNCTION; | |
| /*-----------------------------------------------------------*/ | |
| /* STATIC FUNCTIONS ARE DEFINED AS MACROS TO MINIMIZE THE FUNCTION CALL DEPTH. */ | |
| /* | |
| * Insert a block into the list of free blocks - which is ordered by size of | |
| * the block. Small blocks at the start of the list and large blocks at the end | |
| * of the list. | |
| */ | |
| #define prvInsertBlockIntoFreeList( pxBlockToInsert ) \ | |
| { \ | |
| BlockLink_t * pxIterator; \ | |
| size_t xBlockSize; \ | |
| \ | |
| xBlockSize = pxBlockToInsert->xBlockSize; \ | |
| \ | |
| /* Iterate through the list until a block is found that has a larger size */ \ | |
| /* than the block we are inserting. */ \ | |
| for( pxIterator = &xStart; pxIterator->pxNextFreeBlock->xBlockSize < xBlockSize; pxIterator = pxIterator->pxNextFreeBlock ) \ | |
| { \ | |
| /* There is nothing to do here - just iterate to the correct position. */ \ | |
| } \ | |
| \ | |
| /* Update the list to include the block being inserted in the correct */ \ | |
| /* position. */ \ | |
| pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock; \ | |
| pxIterator->pxNextFreeBlock = pxBlockToInsert; \ | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void * pvPortMalloc( size_t xWantedSize ) | |
| { | |
| BlockLink_t * pxBlock, * pxPreviousBlock, * pxNewBlockLink; | |
| PRIVILEGED_DATA static BaseType_t xHeapHasBeenInitialised = pdFALSE; | |
| void * pvReturn = NULL; | |
| size_t xAdditionalRequiredSize; | |
| vTaskSuspendAll(); | |
| { | |
| /* If this is the first call to malloc then the heap will require | |
| * initialisation to setup the list of free blocks. */ | |
| if( xHeapHasBeenInitialised == pdFALSE ) | |
| { | |
| prvHeapInit(); | |
| xHeapHasBeenInitialised = pdTRUE; | |
| } | |
| if( xWantedSize > 0 ) | |
| { | |
| /* The wanted size must be increased so it can contain a BlockLink_t | |
| * structure in addition to the requested amount of bytes. Some | |
| * additional increment may also be needed for alignment. */ | |
| xAdditionalRequiredSize = heapSTRUCT_SIZE + portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ); | |
| if( heapADD_WILL_OVERFLOW( xWantedSize, xAdditionalRequiredSize ) == 0 ) | |
| { | |
| xWantedSize += xAdditionalRequiredSize; | |
| } | |
| else | |
| { | |
| xWantedSize = 0; | |
| } | |
| } | |
| /* Check the block size we are trying to allocate is not so large that the | |
| * top bit is set. The top bit of the block size member of the BlockLink_t | |
| * structure is used to determine who owns the block - the application or | |
| * the kernel, so it must be free. */ | |
| if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) != 0 ) | |
| { | |
| if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) ) | |
| { | |
| /* Blocks are stored in byte order - traverse the list from the start | |
| * (smallest) block until one of adequate size is found. */ | |
| pxPreviousBlock = &xStart; | |
| pxBlock = xStart.pxNextFreeBlock; | |
| while( ( pxBlock->xBlockSize < xWantedSize ) && ( pxBlock->pxNextFreeBlock != NULL ) ) | |
| { | |
| pxPreviousBlock = pxBlock; | |
| pxBlock = pxBlock->pxNextFreeBlock; | |
| } | |
| /* If we found the end marker then a block of adequate size was not found. */ | |
| if( pxBlock != &xEnd ) | |
| { | |
| /* Return the memory space - jumping over the BlockLink_t structure | |
| * at its start. */ | |
| pvReturn = ( void * ) ( ( ( uint8_t * ) pxPreviousBlock->pxNextFreeBlock ) + heapSTRUCT_SIZE ); | |
| /* This block is being returned for use so must be taken out of the | |
| * list of free blocks. */ | |
| pxPreviousBlock->pxNextFreeBlock = pxBlock->pxNextFreeBlock; | |
| /* If the block is larger than required it can be split into two. */ | |
| if( ( pxBlock->xBlockSize - xWantedSize ) > heapMINIMUM_BLOCK_SIZE ) | |
| { | |
| /* This block is to be split into two. Create a new block | |
| * following the number of bytes requested. The void cast is | |
| * used to prevent byte alignment warnings from the compiler. */ | |
| pxNewBlockLink = ( void * ) ( ( ( uint8_t * ) pxBlock ) + xWantedSize ); | |
| /* Calculate the sizes of two blocks split from the single | |
| * block. */ | |
| pxNewBlockLink->xBlockSize = pxBlock->xBlockSize - xWantedSize; | |
| pxBlock->xBlockSize = xWantedSize; | |
| /* Insert the new block into the list of free blocks. */ | |
| prvInsertBlockIntoFreeList( ( pxNewBlockLink ) ); | |
| } | |
| xFreeBytesRemaining -= pxBlock->xBlockSize; | |
| /* The block is being returned - it is allocated and owned | |
| * by the application and has no "next" block. */ | |
| heapALLOCATE_BLOCK( pxBlock ); | |
| pxBlock->pxNextFreeBlock = NULL; | |
| } | |
| } | |
| } | |
| traceMALLOC( pvReturn, xWantedSize ); | |
| } | |
| ( void ) xTaskResumeAll(); | |
| #if ( configUSE_MALLOC_FAILED_HOOK == 1 ) | |
| { | |
| if( pvReturn == NULL ) | |
| { | |
| vApplicationMallocFailedHook(); | |
| } | |
| } | |
| #endif | |
| return pvReturn; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vPortFree( void * pv ) | |
| { | |
| uint8_t * puc = ( uint8_t * ) pv; | |
| BlockLink_t * pxLink; | |
| if( pv != NULL ) | |
| { | |
| /* The memory being freed will have an BlockLink_t structure immediately | |
| * before it. */ | |
| puc -= heapSTRUCT_SIZE; | |
| /* This unexpected casting is to keep some compilers from issuing | |
| * byte alignment warnings. */ | |
| pxLink = ( void * ) puc; | |
| configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) != 0 ); | |
| configASSERT( pxLink->pxNextFreeBlock == NULL ); | |
| if( heapBLOCK_IS_ALLOCATED( pxLink ) != 0 ) | |
| { | |
| if( pxLink->pxNextFreeBlock == NULL ) | |
| { | |
| /* The block is being returned to the heap - it is no longer | |
| * allocated. */ | |
| heapFREE_BLOCK( pxLink ); | |
| #if ( configHEAP_CLEAR_MEMORY_ON_FREE == 1 ) | |
| { | |
| ( void ) memset( puc + heapSTRUCT_SIZE, 0, pxLink->xBlockSize - heapSTRUCT_SIZE ); | |
| } | |
| #endif | |
| vTaskSuspendAll(); | |
| { | |
| /* Add this block to the list of free blocks. */ | |
| prvInsertBlockIntoFreeList( ( ( BlockLink_t * ) pxLink ) ); | |
| xFreeBytesRemaining += pxLink->xBlockSize; | |
| traceFREE( pv, pxLink->xBlockSize ); | |
| } | |
| ( void ) xTaskResumeAll(); | |
| } | |
| } | |
| } | |
| } | |
| /*-----------------------------------------------------------*/ | |
| size_t xPortGetFreeHeapSize( void ) | |
| { | |
| return xFreeBytesRemaining; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vPortInitialiseBlocks( void ) | |
| { | |
| /* This just exists to keep the linker quiet. */ | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void * pvPortCalloc( size_t xNum, | |
| size_t xSize ) | |
| { | |
| void * pv = NULL; | |
| if( heapMULTIPLY_WILL_OVERFLOW( xNum, xSize ) == 0 ) | |
| { | |
| pv = pvPortMalloc( xNum * xSize ); | |
| if( pv != NULL ) | |
| { | |
| ( void ) memset( pv, 0, xNum * xSize ); | |
| } | |
| } | |
| return pv; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| static void prvHeapInit( void ) /* PRIVILEGED_FUNCTION */ | |
| { | |
| BlockLink_t * pxFirstFreeBlock; | |
| uint8_t * pucAlignedHeap; | |
| /* Ensure the heap starts on a correctly aligned boundary. */ | |
| pucAlignedHeap = ( uint8_t * ) ( ( ( portPOINTER_SIZE_TYPE ) & ucHeap[ portBYTE_ALIGNMENT - 1 ] ) & ( ~( ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) ) ); | |
| /* xStart is used to hold a pointer to the first item in the list of free | |
| * blocks. The void cast is used to prevent compiler warnings. */ | |
| xStart.pxNextFreeBlock = ( void * ) pucAlignedHeap; | |
| xStart.xBlockSize = ( size_t ) 0; | |
| /* xEnd is used to mark the end of the list of free blocks. */ | |
| xEnd.xBlockSize = configADJUSTED_HEAP_SIZE; | |
| xEnd.pxNextFreeBlock = NULL; | |
| /* To start with there is a single free block that is sized to take up the | |
| * entire heap space. */ | |
| pxFirstFreeBlock = ( void * ) pucAlignedHeap; | |
| pxFirstFreeBlock->xBlockSize = configADJUSTED_HEAP_SIZE; | |
| pxFirstFreeBlock->pxNextFreeBlock = &xEnd; | |
| } | |
| /*-----------------------------------------------------------*/ |