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>
diff --git a/include/portable.h b/include/portable.h
index 22bb9b0..0feedad 100644
--- a/include/portable.h
+++ b/include/portable.h
@@ -173,6 +173,8 @@
* Map to the memory management routines required for the port.
*/
void * pvPortMalloc( size_t xSize ) PRIVILEGED_FUNCTION;
+void * pvPortCalloc( size_t xNum,
+ size_t xSize ) PRIVILEGED_FUNCTION;
void vPortFree( void * pv ) PRIVILEGED_FUNCTION;
void vPortInitialiseBlocks( void ) PRIVILEGED_FUNCTION;
size_t xPortGetFreeHeapSize( void ) PRIVILEGED_FUNCTION;
diff --git a/portable/MemMang/heap_2.c b/portable/MemMang/heap_2.c
index 4974f14..85ebdf2 100644
--- a/portable/MemMang/heap_2.c
+++ b/portable/MemMang/heap_2.c
@@ -36,6 +36,7 @@
* 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
@@ -51,13 +52,30 @@
#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 )
-/*
- * Initialises the heap structures before their first use.
- */
-static void prvHeapInit( void );
+/* 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 )
+
+/*-----------------------------------------------------------*/
/* Allocate the memory for the heap. */
#if ( configAPPLICATION_ALLOCATED_HEAP == 1 )
@@ -66,7 +84,7 @@
* heap - probably so it can be placed in a special segment or address. */
extern uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
#else
- static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
+ PRIVILEGED_DATA static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
#endif /* configAPPLICATION_ALLOCATED_HEAP */
@@ -83,11 +101,20 @@
#define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( heapSTRUCT_SIZE * 2 ) )
/* Create a couple of list links to mark the start and end of the list. */
-static BlockLink_t xStart, xEnd;
+PRIVILEGED_DATA static BlockLink_t xStart, xEnd;
/* Keeps track of the number of free bytes remaining, but says nothing about
* fragmentation. */
-static size_t xFreeBytesRemaining = configADJUSTED_HEAP_SIZE;
+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. */
@@ -120,7 +147,7 @@
void * pvPortMalloc( size_t xWantedSize )
{
BlockLink_t * pxBlock, * pxPreviousBlock, * pxNewBlockLink;
- static BaseType_t xHeapHasBeenInitialised = pdFALSE;
+ PRIVILEGED_DATA static BaseType_t xHeapHasBeenInitialised = pdFALSE;
void * pvReturn = NULL;
vTaskSuspendAll();
@@ -133,72 +160,84 @@
xHeapHasBeenInitialised = pdTRUE;
}
- /* The wanted size must be increased so it can contain a BlockLink_t
- * structure in addition to the requested amount of bytes. */
- if( ( xWantedSize > 0 ) &&
- ( ( xWantedSize + heapSTRUCT_SIZE ) > xWantedSize ) ) /* Overflow check */
+ /* Check the requested block size 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 ) )
{
- xWantedSize += heapSTRUCT_SIZE;
-
- /* Byte alignment required. Check for overflow. */
- if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) )
- > xWantedSize )
+ /* The wanted size must be increased so it can contain a BlockLink_t
+ * structure in addition to the requested amount of bytes. */
+ if( ( xWantedSize > 0 ) &&
+ ( ( xWantedSize + heapSTRUCT_SIZE ) > xWantedSize ) ) /* Overflow check */
{
- xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
- configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
+ xWantedSize += heapSTRUCT_SIZE;
+
+ /* Byte alignment required. Check for overflow. */
+ if( ( xWantedSize + ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ) )
+ > xWantedSize )
+ {
+ xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
+ configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
+ }
+ else
+ {
+ xWantedSize = 0;
+ }
}
else
{
xWantedSize = 0;
}
- }
- else
- {
- 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 ) )
+ if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) )
{
- pxPreviousBlock = pxBlock;
- pxBlock = pxBlock->pxNextFreeBlock;
- }
+ /* 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;
- /* 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 )
+ while( ( pxBlock->xBlockSize < xWantedSize ) && ( pxBlock->pxNextFreeBlock != NULL ) )
{
- /* 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 ) );
+ pxPreviousBlock = pxBlock;
+ pxBlock = pxBlock->pxNextFreeBlock;
}
- xFreeBytesRemaining -= pxBlock->xBlockSize;
+ /* 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;
+ }
}
}
@@ -235,14 +274,32 @@
* byte alignment warnings. */
pxLink = ( void * ) puc;
- vTaskSuspendAll();
+ configASSERT( heapBLOCK_IS_ALLOCATED( pxLink ) );
+ configASSERT( pxLink->pxNextFreeBlock == NULL );
+
+ if( heapBLOCK_IS_ALLOCATED( pxLink ) )
{
- /* Add this block to the list of free blocks. */
- prvInsertBlockIntoFreeList( ( ( BlockLink_t * ) pxLink ) );
- xFreeBytesRemaining += pxLink->xBlockSize;
- traceFREE( pv, pxLink->xBlockSize );
+ 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();
+ }
}
- ( void ) xTaskResumeAll();
}
}
/*-----------------------------------------------------------*/
@@ -259,7 +316,27 @@
}
/*-----------------------------------------------------------*/
-static void prvHeapInit( 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;
uint8_t * pucAlignedHeap;
diff --git a/portable/MemMang/heap_4.c b/portable/MemMang/heap_4.c
index 79f6666..2ef5381 100644
--- a/portable/MemMang/heap_4.c
+++ b/portable/MemMang/heap_4.c
@@ -35,6 +35,7 @@
* 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
@@ -50,12 +51,31 @@
#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 )
+
+/*-----------------------------------------------------------*/
+
/* Allocate the memory for the heap. */
#if ( configAPPLICATION_ALLOCATED_HEAP == 1 )
@@ -106,12 +126,6 @@
PRIVILEGED_DATA static size_t xNumberOfSuccessfulAllocations = 0;
PRIVILEGED_DATA 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. */
-PRIVILEGED_DATA static size_t xBlockAllocatedBit = 0;
-
/*-----------------------------------------------------------*/
void * pvPortMalloc( size_t xWantedSize )
@@ -136,7 +150,7 @@
* 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 must be increased so it can contain a BlockLink_t
* structure in addition to the requested amount of bytes. */
@@ -232,7 +246,7 @@
/* 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++;
}
@@ -288,17 +302,21 @@
/* 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();
{
@@ -341,6 +359,26 @@
}
/*-----------------------------------------------------------*/
+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 @@
/* 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 @@
}
taskEXIT_CRITICAL();
}
+/*-----------------------------------------------------------*/
diff --git a/portable/MemMang/heap_5.c b/portable/MemMang/heap_5.c
index c0d92ed..c12c956 100644
--- a/portable/MemMang/heap_5.c
+++ b/portable/MemMang/heap_5.c
@@ -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 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 @@
* 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 @@
/* 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 @@
/* 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 @@
}
/*-----------------------------------------------------------*/
+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 @@
/* 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 @@
}
taskEXIT_CRITICAL();
}
+/*-----------------------------------------------------------*/
