Heap improvements (#462)
* Heap improvements This commit makes the following improvements: 1. Add a check to heap_2 to track if a memory block is allocated to the application or not. The MSB of the size field is used for this purpose. The same check already exists in heap_4 and heap_5. This check prevents against double free. 2. Add a new flag configHEAP_CLEAR_MEMORY_ON_FREE to heap_2, heap_4 and heap_5. The application writer can set it to 1 in their FreeRTOSConfig.h to ensure that a block of memory allocated using pvPortMalloc is cleared (i.e. set to zero) when it is freed using vPortFree. If left undefined, configHEAP_CLEAR_MEMORY_ON_FREE defaults to 0 for backward compatibility. We recommend setting configHEAP_CLEAR_MEMORY_ON_FREE to 1 for better security. 3. Add a new API pvPortCalloc to heap_2, heap_4 and heap_5. This API has the following signature: void * pvPortCalloc( size_t xNum, size_t xSize ); It allocates memory for an array of xNum objects each of which is of xSize and initializes all bytes in the allocated storage to zero. If allocation succeeds, it returns a pointer to the lowest byte in the allocated memory block. On failure, it returns a null pointer. Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com>
This commit is contained in:
Gaurav-Aggarwal-AWS
GitHub
parent
4539e1c574
commit
82be77995e
@ -173,6 +173,8 @@ void vPortGetHeapStats( HeapStats_t * pxHeapStats );
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* Map to the memory management routines required for the port.
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*/
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void * pvPortMalloc( size_t xSize ) PRIVILEGED_FUNCTION;
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void * pvPortCalloc( size_t xNum,
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size_t xSize ) PRIVILEGED_FUNCTION;
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void vPortFree( void * pv ) PRIVILEGED_FUNCTION;
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void vPortInitialiseBlocks( void ) PRIVILEGED_FUNCTION;
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size_t xPortGetFreeHeapSize( void ) PRIVILEGED_FUNCTION;
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@ -36,6 +36,7 @@
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* memory management pages of https://www.FreeRTOS.org for more information.
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*/
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#include <stdlib.h>
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#include <string.h>
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/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
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* all the API functions to use the MPU wrappers. That should only be done when
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@ -51,13 +52,30 @@
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#error This file must not be used if configSUPPORT_DYNAMIC_ALLOCATION is 0
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#endif
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#ifndef configHEAP_CLEAR_MEMORY_ON_FREE
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#define configHEAP_CLEAR_MEMORY_ON_FREE 0
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#endif
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/* A few bytes might be lost to byte aligning the heap start address. */
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#define configADJUSTED_HEAP_SIZE ( configTOTAL_HEAP_SIZE - portBYTE_ALIGNMENT )
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/*
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* Initialises the heap structures before their first use.
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*/
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static void prvHeapInit( void );
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/* Assumes 8bit bytes! */
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#define heapBITS_PER_BYTE ( ( size_t ) 8 )
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/* Check if multiplying a and b will result in overflow. */
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#define heapMULTIPLY_WILL_OVERFLOW( a, b, max ) ( ( ( a ) > 0 ) && ( ( b ) > ( ( max ) / ( a ) ) ) )
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/* MSB of the xBlockSize member of an BlockLink_t structure is used to track
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* the allocation status of a block. When MSB of the xBlockSize member of
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* an BlockLink_t structure is set then the block belongs to the application.
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* When the bit is free the block is still part of the free heap space. */
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#define heapBLOCK_ALLOCATED_BITMASK ( ( ( size_t ) 1 ) << ( ( sizeof( size_t ) * heapBITS_PER_BYTE ) - 1 ) )
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#define heapBLOCK_SIZE_IS_VALID( xBlockSize ) ( ( ( xBlockSize ) & heapBLOCK_ALLOCATED_BITMASK ) == 0 )
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#define heapBLOCK_IS_ALLOCATED( pxBlock ) ( ( ( pxBlock->xBlockSize ) & heapBLOCK_ALLOCATED_BITMASK ) != 0 )
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#define heapALLOCATE_BLOCK( pxBlock ) ( ( pxBlock->xBlockSize ) |= heapBLOCK_ALLOCATED_BITMASK )
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#define heapFREE_BLOCK( pxBlock ) ( ( pxBlock->xBlockSize ) &= ~heapBLOCK_ALLOCATED_BITMASK )
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/*-----------------------------------------------------------*/
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/* Allocate the memory for the heap. */
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#if ( configAPPLICATION_ALLOCATED_HEAP == 1 )
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@ -66,7 +84,7 @@ static void prvHeapInit( void );
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* heap - probably so it can be placed in a special segment or address. */
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extern uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
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#else
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static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
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PRIVILEGED_DATA static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
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#endif /* configAPPLICATION_ALLOCATED_HEAP */
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@ -83,11 +101,20 @@ static const uint16_t heapSTRUCT_SIZE = ( ( sizeof( BlockLink_t ) + ( portBYTE_A
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#define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( heapSTRUCT_SIZE * 2 ) )
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/* Create a couple of list links to mark the start and end of the list. */
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static BlockLink_t xStart, xEnd;
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PRIVILEGED_DATA static BlockLink_t xStart, xEnd;
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/* Keeps track of the number of free bytes remaining, but says nothing about
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* fragmentation. */
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static size_t xFreeBytesRemaining = configADJUSTED_HEAP_SIZE;
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PRIVILEGED_DATA static size_t xFreeBytesRemaining = configADJUSTED_HEAP_SIZE;
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/*-----------------------------------------------------------*/
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/*
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* Initialises the heap structures before their first use.
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*/
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static void prvHeapInit( void ) PRIVILEGED_FUNCTION;
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/*-----------------------------------------------------------*/
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/* STATIC FUNCTIONS ARE DEFINED AS MACROS TO MINIMIZE THE FUNCTION CALL DEPTH. */
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@ -120,7 +147,7 @@ static size_t xFreeBytesRemaining = configADJUSTED_HEAP_SIZE;
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void * pvPortMalloc( size_t xWantedSize )
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{
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BlockLink_t * pxBlock, * pxPreviousBlock, * pxNewBlockLink;
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static BaseType_t xHeapHasBeenInitialised = pdFALSE;
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PRIVILEGED_DATA static BaseType_t xHeapHasBeenInitialised = pdFALSE;
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void * pvReturn = NULL;
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vTaskSuspendAll();
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@ -133,72 +160,84 @@ void * pvPortMalloc( size_t xWantedSize )
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xHeapHasBeenInitialised = pdTRUE;
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}
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/* The wanted size must be increased so it can contain a BlockLink_t
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* structure in addition to the requested amount of bytes. */
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if( ( xWantedSize > 0 ) &&
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( ( xWantedSize + heapSTRUCT_SIZE ) > xWantedSize ) ) /* Overflow check */
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/* Check the requested block size is not so large that the top bit is
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* set. The top bit of the block size member of the BlockLink_t structure
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* is used to determine who owns the block - the application or the
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* kernel, so it must be free. */
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if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) )
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{
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xWantedSize += heapSTRUCT_SIZE;
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/* Byte alignment required. Check for overflow. */
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if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) )
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> xWantedSize )
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/* The wanted size must be increased so it can contain a BlockLink_t
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* structure in addition to the requested amount of bytes. */
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if( ( xWantedSize > 0 ) &&
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( ( xWantedSize + heapSTRUCT_SIZE ) > xWantedSize ) ) /* Overflow check */
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{
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xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
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configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
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xWantedSize += heapSTRUCT_SIZE;
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/* Byte alignment required. Check for overflow. */
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if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) )
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> xWantedSize )
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{
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xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
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configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
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}
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else
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{
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xWantedSize = 0;
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}
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}
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else
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{
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xWantedSize = 0;
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}
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}
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else
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{
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xWantedSize = 0;
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}
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if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) )
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{
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/* Blocks are stored in byte order - traverse the list from the start
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* (smallest) block until one of adequate size is found. */
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pxPreviousBlock = &xStart;
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pxBlock = xStart.pxNextFreeBlock;
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while( ( pxBlock->xBlockSize < xWantedSize ) && ( pxBlock->pxNextFreeBlock != NULL ) )
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if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) )
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{
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pxPreviousBlock = pxBlock;
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pxBlock = pxBlock->pxNextFreeBlock;
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}
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/* Blocks are stored in byte order - traverse the list from the start
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* (smallest) block until one of adequate size is found. */
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pxPreviousBlock = &xStart;
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pxBlock = xStart.pxNextFreeBlock;
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/* If we found the end marker then a block of adequate size was not found. */
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if( pxBlock != &xEnd )
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{
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/* Return the memory space - jumping over the BlockLink_t structure
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* at its start. */
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pvReturn = ( void * ) ( ( ( uint8_t * ) pxPreviousBlock->pxNextFreeBlock ) + heapSTRUCT_SIZE );
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/* This block is being returned for use so must be taken out of the
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* list of free blocks. */
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pxPreviousBlock->pxNextFreeBlock = pxBlock->pxNextFreeBlock;
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/* If the block is larger than required it can be split into two. */
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if( ( pxBlock->xBlockSize - xWantedSize ) > heapMINIMUM_BLOCK_SIZE )
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while( ( pxBlock->xBlockSize < xWantedSize ) && ( pxBlock->pxNextFreeBlock != NULL ) )
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{
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/* This block is to be split into two. Create a new block
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* following the number of bytes requested. The void cast is
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* used to prevent byte alignment warnings from the compiler. */
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pxNewBlockLink = ( void * ) ( ( ( uint8_t * ) pxBlock ) + xWantedSize );
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/* Calculate the sizes of two blocks split from the single
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* block. */
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pxNewBlockLink->xBlockSize = pxBlock->xBlockSize - xWantedSize;
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pxBlock->xBlockSize = xWantedSize;
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/* Insert the new block into the list of free blocks. */
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prvInsertBlockIntoFreeList( ( pxNewBlockLink ) );
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pxPreviousBlock = pxBlock;
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pxBlock = pxBlock->pxNextFreeBlock;
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}
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xFreeBytesRemaining -= pxBlock->xBlockSize;
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/* If we found the end marker then a block of adequate size was not found. */
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if( pxBlock != &xEnd )
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{
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/* Return the memory space - jumping over the BlockLink_t structure
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* at its start. */
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pvReturn = ( void * ) ( ( ( uint8_t * ) pxPreviousBlock->pxNextFreeBlock ) + heapSTRUCT_SIZE );
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/* This block is being returned for use so must be taken out of the
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* list of free blocks. */
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pxPreviousBlock->pxNextFreeBlock = pxBlock->pxNextFreeBlock;
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/* If the block is larger than required it can be split into two. */
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if( ( pxBlock->xBlockSize - xWantedSize ) > heapMINIMUM_BLOCK_SIZE )
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{
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/* This block is to be split into two. Create a new block
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* following the number of bytes requested. The void cast is
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* used to prevent byte alignment warnings from the compiler. */
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pxNewBlockLink = ( void * ) ( ( ( uint8_t * ) pxBlock ) + xWantedSize );
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/* Calculate the sizes of two blocks split from the single
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* block. */
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pxNewBlockLink->xBlockSize = pxBlock->xBlockSize - xWantedSize;
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pxBlock->xBlockSize = xWantedSize;
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/* Insert the new block into the list of free blocks. */
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prvInsertBlockIntoFreeList( ( pxNewBlockLink ) );
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}
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xFreeBytesRemaining -= pxBlock->xBlockSize;
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/* The block is being returned - it is allocated and owned
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* by the application and has no "next" block. */
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heapALLOCATE_BLOCK( pxBlock );
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pxBlock->pxNextFreeBlock = NULL;
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}
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}
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}
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@ -235,14 +274,32 @@ void vPortFree( void * pv )
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* byte alignment warnings. */
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pxLink = ( void * ) puc;
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vTaskSuspendAll();
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configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) );
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configASSERT( pxLink->pxNextFreeBlock == NULL );
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if( heapBLOCK_IS_ALLOCATED( pxLink ) )
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{
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/* Add this block to the list of free blocks. */
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prvInsertBlockIntoFreeList( ( ( BlockLink_t * ) pxLink ) );
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xFreeBytesRemaining += pxLink->xBlockSize;
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traceFREE( pv, pxLink->xBlockSize );
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if( pxLink->pxNextFreeBlock == NULL )
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{
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/* The block is being returned to the heap - it is no longer
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* allocated. */
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heapFREE_BLOCK( pxLink );
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#if ( configHEAP_CLEAR_MEMORY_ON_FREE == 1 )
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{
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( void ) memset( puc + heapSTRUCT_SIZE, 0, pxLink->xBlockSize - heapSTRUCT_SIZE );
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}
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#endif
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vTaskSuspendAll();
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{
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/* Add this block to the list of free blocks. */
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prvInsertBlockIntoFreeList( ( ( BlockLink_t * ) pxLink ) );
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xFreeBytesRemaining += pxLink->xBlockSize;
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traceFREE( pv, pxLink->xBlockSize );
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}
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( void ) xTaskResumeAll();
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}
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}
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( void ) xTaskResumeAll();
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}
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}
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/*-----------------------------------------------------------*/
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@ -259,7 +316,27 @@ void vPortInitialiseBlocks( void )
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}
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/*-----------------------------------------------------------*/
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static void prvHeapInit( void )
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void * pvPortCalloc( size_t xNum,
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size_t xSize )
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{
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void * pv = NULL;
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const size_t xSizeMaxValue = ~( ( size_t ) 0 );
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if( !heapMULTIPLY_WILL_OVERFLOW( xNum, xSize, xSizeMaxValue ) )
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{
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pv = pvPortMalloc( xNum * xSize );
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if( pv != NULL )
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{
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( void ) memset( pv, 0, xNum * xSize );
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}
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}
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return pv;
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}
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/*-----------------------------------------------------------*/
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static void prvHeapInit( void ) /* PRIVILEGED_FUNCTION */
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{
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BlockLink_t * pxFirstFreeBlock;
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uint8_t * pucAlignedHeap;
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@ -35,6 +35,7 @@
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* memory management pages of https://www.FreeRTOS.org for more information.
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*/
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#include <stdlib.h>
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#include <string.h>
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/* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
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* all the API functions to use the MPU wrappers. That should only be done when
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@ -50,12 +51,31 @@
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#error This file must not be used if configSUPPORT_DYNAMIC_ALLOCATION is 0
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#endif
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#ifndef configHEAP_CLEAR_MEMORY_ON_FREE
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#define configHEAP_CLEAR_MEMORY_ON_FREE 0
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#endif
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/* Block sizes must not get too small. */
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#define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( xHeapStructSize << 1 ) )
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/* Assumes 8bit bytes! */
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#define heapBITS_PER_BYTE ( ( size_t ) 8 )
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/* Check if multiplying a and b will result in overflow. */
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#define heapMULTIPLY_WILL_OVERFLOW( a, b, max ) ( ( ( a ) > 0 ) && ( ( b ) > ( ( max ) / ( a ) ) ) )
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/* MSB of the xBlockSize member of an BlockLink_t structure is used to track
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* the allocation status of a block. When MSB of the xBlockSize member of
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* an BlockLink_t structure is set then the block belongs to the application.
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* When the bit is free the block is still part of the free heap space. */
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#define heapBLOCK_ALLOCATED_BITMASK ( ( ( size_t ) 1 ) << ( ( sizeof( size_t ) * heapBITS_PER_BYTE ) - 1 ) )
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#define heapBLOCK_SIZE_IS_VALID( xBlockSize ) ( ( ( xBlockSize ) & heapBLOCK_ALLOCATED_BITMASK ) == 0 )
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#define heapBLOCK_IS_ALLOCATED( pxBlock ) ( ( ( pxBlock->xBlockSize ) & heapBLOCK_ALLOCATED_BITMASK ) != 0 )
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#define heapALLOCATE_BLOCK( pxBlock ) ( ( pxBlock->xBlockSize ) |= heapBLOCK_ALLOCATED_BITMASK )
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#define heapFREE_BLOCK( pxBlock ) ( ( pxBlock->xBlockSize ) &= ~heapBLOCK_ALLOCATED_BITMASK )
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/*-----------------------------------------------------------*/
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/* Allocate the memory for the heap. */
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#if ( configAPPLICATION_ALLOCATED_HEAP == 1 )
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@ -106,12 +126,6 @@ PRIVILEGED_DATA static size_t xMinimumEverFreeBytesRemaining = 0U;
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PRIVILEGED_DATA static size_t xNumberOfSuccessfulAllocations = 0;
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PRIVILEGED_DATA static size_t xNumberOfSuccessfulFrees = 0;
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/* Gets set to the top bit of an size_t type. When this bit in the xBlockSize
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* member of an BlockLink_t structure is set then the block belongs to the
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* application. When the bit is free the block is still part of the free heap
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* space. */
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PRIVILEGED_DATA static size_t xBlockAllocatedBit = 0;
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/*-----------------------------------------------------------*/
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void * pvPortMalloc( size_t xWantedSize )
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@ -136,7 +150,7 @@ void * pvPortMalloc( size_t xWantedSize )
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* set. The top bit of the block size member of the BlockLink_t structure
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* is used to determine who owns the block - the application or the
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* kernel, so it must be free. */
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if( ( xWantedSize & xBlockAllocatedBit ) == 0 )
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if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) )
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{
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/* The wanted size must be increased so it can contain a BlockLink_t
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* structure in addition to the requested amount of bytes. */
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@ -232,7 +246,7 @@ void * pvPortMalloc( size_t xWantedSize )
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/* The block is being returned - it is allocated and owned
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* by the application and has no "next" block. */
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pxBlock->xBlockSize |= xBlockAllocatedBit;
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heapALLOCATE_BLOCK( pxBlock );
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pxBlock->pxNextFreeBlock = NULL;
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xNumberOfSuccessfulAllocations++;
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}
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@ -288,17 +302,21 @@ void vPortFree( void * pv )
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/* This casting is to keep the compiler from issuing warnings. */
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pxLink = ( void * ) puc;
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/* Check the block is actually allocated. */
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configASSERT( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 );
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configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) );
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configASSERT( pxLink->pxNextFreeBlock == NULL );
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if( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 )
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if( heapBLOCK_IS_ALLOCATED( pxLink ) )
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{
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if( pxLink->pxNextFreeBlock == NULL )
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{
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/* The block is being returned to the heap - it is no longer
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* allocated. */
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pxLink->xBlockSize &= ~xBlockAllocatedBit;
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heapFREE_BLOCK( pxLink );
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#if ( configHEAP_CLEAR_MEMORY_ON_FREE == 1 )
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{
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( void ) memset( puc + xHeapStructSize, 0, pxLink->xBlockSize - xHeapStructSize );
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}
|
||||
#endif
|
||||
|
||||
vTaskSuspendAll();
|
||||
{
|
||||
@ -341,6 +359,26 @@ void vPortInitialiseBlocks( void )
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
void * pvPortCalloc( size_t xNum,
|
||||
size_t xSize )
|
||||
{
|
||||
void * pv = NULL;
|
||||
const size_t xSizeMaxValue = ~( ( size_t ) 0 );
|
||||
|
||||
if( !heapMULTIPLY_WILL_OVERFLOW( xNum, xSize, xSizeMaxValue ) )
|
||||
{
|
||||
pv = pvPortMalloc( xNum * xSize );
|
||||
|
||||
if( pv != NULL )
|
||||
{
|
||||
( void ) memset( pv, 0, xNum * xSize );
|
||||
}
|
||||
}
|
||||
|
||||
return pv;
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
static void prvHeapInit( void ) /* PRIVILEGED_FUNCTION */
|
||||
{
|
||||
BlockLink_t * pxFirstFreeBlock;
|
||||
@ -383,9 +421,6 @@ static void prvHeapInit( void ) /* PRIVILEGED_FUNCTION */
|
||||
/* Only one block exists - and it covers the entire usable heap space. */
|
||||
xMinimumEverFreeBytesRemaining = pxFirstFreeBlock->xBlockSize;
|
||||
xFreeBytesRemaining = pxFirstFreeBlock->xBlockSize;
|
||||
|
||||
/* Work out the position of the top bit in a size_t variable. */
|
||||
xBlockAllocatedBit = ( ( size_t ) 1 ) << ( ( sizeof( size_t ) * heapBITS_PER_BYTE ) - 1 );
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
@ -502,3 +537,4 @@ void vPortGetHeapStats( HeapStats_t * pxHeapStats )
|
||||
}
|
||||
taskEXIT_CRITICAL();
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
@ -69,6 +69,7 @@
|
||||
*
|
||||
*/
|
||||
#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
|
||||
@ -84,12 +85,31 @@
|
||||
#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
|
||||
|
||||
/* Block sizes must not get too small. */
|
||||
#define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( xHeapStructSize << 1 ) )
|
||||
|
||||
/* Assumes 8bit bytes! */
|
||||
#define heapBITS_PER_BYTE ( ( size_t ) 8 )
|
||||
|
||||
/* Check if multiplying a and b will result in overflow. */
|
||||
#define heapMULTIPLY_WILL_OVERFLOW( a, b, max ) ( ( ( a ) > 0 ) && ( ( b ) > ( ( max ) / ( a ) ) ) )
|
||||
|
||||
/* 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 )
|
||||
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
/* Define the linked list structure. This is used to link free blocks in order
|
||||
* of their memory address. */
|
||||
typedef struct A_BLOCK_LINK
|
||||
@ -124,12 +144,6 @@ static size_t xMinimumEverFreeBytesRemaining = 0U;
|
||||
static size_t xNumberOfSuccessfulAllocations = 0;
|
||||
static size_t xNumberOfSuccessfulFrees = 0;
|
||||
|
||||
/* Gets set to the top bit of an size_t type. When this bit in 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. */
|
||||
static size_t xBlockAllocatedBit = 0;
|
||||
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
void * pvPortMalloc( size_t xWantedSize )
|
||||
@ -147,7 +161,7 @@ void * pvPortMalloc( size_t xWantedSize )
|
||||
* 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( ( xWantedSize & xBlockAllocatedBit ) == 0 )
|
||||
if( heapBLOCK_SIZE_IS_VALID( xWantedSize ) )
|
||||
{
|
||||
/* The wanted size is increased so it can contain a BlockLink_t
|
||||
* structure in addition to the requested amount of bytes. */
|
||||
@ -241,7 +255,7 @@ void * pvPortMalloc( size_t xWantedSize )
|
||||
|
||||
/* The block is being returned - it is allocated and owned
|
||||
* by the application and has no "next" block. */
|
||||
pxBlock->xBlockSize |= xBlockAllocatedBit;
|
||||
heapALLOCATE_BLOCK( pxBlock );
|
||||
pxBlock->pxNextFreeBlock = NULL;
|
||||
xNumberOfSuccessfulAllocations++;
|
||||
}
|
||||
@ -296,17 +310,21 @@ void vPortFree( void * pv )
|
||||
/* This casting is to keep the compiler from issuing warnings. */
|
||||
pxLink = ( void * ) puc;
|
||||
|
||||
/* Check the block is actually allocated. */
|
||||
configASSERT( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 );
|
||||
configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) );
|
||||
configASSERT( pxLink->pxNextFreeBlock == NULL );
|
||||
|
||||
if( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 )
|
||||
if( heapBLOCK_IS_ALLOCATED( pxLink ) )
|
||||
{
|
||||
if( pxLink->pxNextFreeBlock == NULL )
|
||||
{
|
||||
/* The block is being returned to the heap - it is no longer
|
||||
* allocated. */
|
||||
pxLink->xBlockSize &= ~xBlockAllocatedBit;
|
||||
heapFREE_BLOCK( pxLink );
|
||||
#if ( configHEAP_CLEAR_MEMORY_ON_FREE == 1 )
|
||||
{
|
||||
( void ) memset( puc + xHeapStructSize, 0, pxLink->xBlockSize - xHeapStructSize );
|
||||
}
|
||||
#endif
|
||||
|
||||
vTaskSuspendAll();
|
||||
{
|
||||
@ -343,6 +361,26 @@ size_t xPortGetMinimumEverFreeHeapSize( void )
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
void * pvPortCalloc( size_t xNum,
|
||||
size_t xSize )
|
||||
{
|
||||
void * pv = NULL;
|
||||
const size_t xSizeMaxValue = ~( ( size_t ) 0 );
|
||||
|
||||
if( !heapMULTIPLY_WILL_OVERFLOW( xNum, xSize, xSizeMaxValue ) )
|
||||
{
|
||||
pv = pvPortMalloc( xNum * xSize );
|
||||
|
||||
if( pv != NULL )
|
||||
{
|
||||
( void ) memset( pv, 0, xNum * xSize );
|
||||
}
|
||||
}
|
||||
|
||||
return pv;
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
static void prvInsertBlockIntoFreeList( BlockLink_t * pxBlockToInsert )
|
||||
{
|
||||
BlockLink_t * pxIterator;
|
||||
@ -495,9 +533,6 @@ void vPortDefineHeapRegions( const HeapRegion_t * const pxHeapRegions )
|
||||
|
||||
/* Check something was actually defined before it is accessed. */
|
||||
configASSERT( xTotalHeapSize );
|
||||
|
||||
/* Work out the position of the top bit in a size_t variable. */
|
||||
xBlockAllocatedBit = ( ( size_t ) 1 ) << ( ( sizeof( size_t ) * heapBITS_PER_BYTE ) - 1 );
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
@ -557,3 +592,4 @@ void vPortGetHeapStats( HeapStats_t * pxHeapStats )
|
||||
}
|
||||
taskEXIT_CRITICAL();
|
||||
}
|
||||
/*-----------------------------------------------------------*/
|
||||
|
||||
Reference in New Issue
Block a user