| /* |
| * 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 size_t xHeapStructSize = ( ( sizeof( BlockLink_t ) + ( size_t ) ( portBYTE_ALIGNMENT - 1 ) ) & ~( ( size_t ) portBYTE_ALIGNMENT_MASK ) ); |
| #define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( xHeapStructSize * 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; |
| |
| /* Indicates whether the heap has been initialised or not. */ |
| PRIVILEGED_DATA static BaseType_t xHeapHasBeenInitialised = pdFALSE; |
| |
| /*-----------------------------------------------------------*/ |
| |
| /* |
| * 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; |
| BlockLink_t * pxPreviousBlock; |
| BlockLink_t * pxNewBlockLink; |
| void * pvReturn = NULL; |
| size_t xAdditionalRequiredSize; |
| |
| 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. */ |
| if( heapADD_WILL_OVERFLOW( xWantedSize, xHeapStructSize ) == 0 ) |
| { |
| xWantedSize += xHeapStructSize; |
| |
| /* Ensure that blocks are always aligned to the required number |
| * of bytes. */ |
| if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 ) |
| { |
| /* Byte alignment required. */ |
| xAdditionalRequiredSize = portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ); |
| |
| if( heapADD_WILL_OVERFLOW( xWantedSize, xAdditionalRequiredSize ) == 0 ) |
| { |
| xWantedSize += xAdditionalRequiredSize; |
| } |
| else |
| { |
| xWantedSize = 0; |
| } |
| } |
| else |
| { |
| mtCOVERAGE_TEST_MARKER(); |
| } |
| } |
| else |
| { |
| xWantedSize = 0; |
| } |
| } |
| else |
| { |
| mtCOVERAGE_TEST_MARKER(); |
| } |
| |
| 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; |
| } |
| |
| /* 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 ) + xHeapStructSize ); |
| |
| /* 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. |
| * The list of free blocks is sorted by their size, we have to |
| * iterate to find the right place to insert new block. */ |
| 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 -= xHeapStructSize; |
| |
| /* 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 + xHeapStructSize, 0, pxLink->xBlockSize - xHeapStructSize ); |
| } |
| #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 = ( BlockLink_t * ) pucAlignedHeap; |
| pxFirstFreeBlock->xBlockSize = configADJUSTED_HEAP_SIZE; |
| pxFirstFreeBlock->pxNextFreeBlock = &xEnd; |
| } |
| /*-----------------------------------------------------------*/ |
| |
| /* |
| * Reset the state in this file. This state is normally initialized at start up. |
| * This function must be called by the application before restarting the |
| * scheduler. |
| */ |
| void vPortHeapResetState( void ) |
| { |
| xFreeBytesRemaining = configADJUSTED_HEAP_SIZE; |
| |
| xHeapHasBeenInitialised = pdFALSE; |
| } |
| /*-----------------------------------------------------------*/ |
