/* | |
FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd. | |
*************************************************************************** | |
* * | |
* FreeRTOS tutorial books are available in pdf and paperback. * | |
* Complete, revised, and edited pdf reference manuals are also * | |
* available. * | |
* * | |
* Purchasing FreeRTOS documentation will not only help you, by * | |
* ensuring you get running as quickly as possible and with an * | |
* in-depth knowledge of how to use FreeRTOS, it will also help * | |
* the FreeRTOS project to continue with its mission of providing * | |
* professional grade, cross platform, de facto standard solutions * | |
* for microcontrollers - completely free of charge! * | |
* * | |
* >>> See http://www.FreeRTOS.org/Documentation for details. <<< * | |
* * | |
* Thank you for using FreeRTOS, and thank you for your support! * | |
* * | |
*************************************************************************** | |
This file is part of the FreeRTOS distribution. | |
FreeRTOS is free software; you can redistribute it and/or modify it under | |
the terms of the GNU General Public License (version 2) as published by the | |
Free Software Foundation AND MODIFIED BY the FreeRTOS exception. | |
>>>NOTE<<< The modification to the GPL is included to allow you to | |
distribute a combined work that includes FreeRTOS without being obliged to | |
provide the source code for proprietary components outside of the FreeRTOS | |
kernel. FreeRTOS is distributed in the hope that it will be useful, but | |
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
more details. You should have received a copy of the GNU General Public | |
License and the FreeRTOS license exception along with FreeRTOS; if not it | |
can be viewed here: http://www.freertos.org/a00114.html and also obtained | |
by writing to Richard Barry, contact details for whom are available on the | |
FreeRTOS WEB site. | |
1 tab == 4 spaces! | |
*************************************************************************** | |
* * | |
* Having a problem? Start by reading the FAQ "My application does * | |
* not run, what could be wrong? * | |
* * | |
* http://www.FreeRTOS.org/FAQHelp.html * | |
* * | |
*************************************************************************** | |
http://www.FreeRTOS.org - Documentation, training, latest information, | |
license and contact details. | |
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, | |
including FreeRTOS+Trace - an indispensable productivity tool. | |
Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell | |
the code with commercial support, indemnification, and middleware, under | |
the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also | |
provide a safety engineered and independently SIL3 certified version under | |
the SafeRTOS brand: http://www.SafeRTOS.com. | |
*/ | |
/* | |
* A sample implementation of pvPortMalloc() and vPortFree() that combines | |
* (coalescences) adjacent memory blocks as they are freed, and in so doing | |
* limits memory fragmentation. | |
* | |
* See heap_1.c, heap_2.c and heap_3.c for alternative implementations, and the | |
* memory management pages of http://www.FreeRTOS.org for more information. | |
*/ | |
#include <stdlib.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 | |
/* Block sizes must not get too small. */ | |
#define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( heapSTRUCT_SIZE * 2 ) ) | |
/* Allocate the memory for the heap. The struct is used to force byte | |
alignment without using any non-portable code. */ | |
static union xRTOS_HEAP | |
{ | |
#if portBYTE_ALIGNMENT == 8 | |
volatile portDOUBLE dDummy; | |
#else | |
volatile unsigned long ulDummy; | |
#endif | |
unsigned char ucHeap[ configTOTAL_HEAP_SIZE ]; | |
} xHeap; | |
/* Define the linked list structure. This is used to link free blocks in order | |
of their memory address. */ | |
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. */ | |
} xBlockLink; | |
/*-----------------------------------------------------------*/ | |
/* | |
* Inserts a block of memory that is being freed into the correct position in | |
* the list of free memory blocks. The block being freed will be merged with | |
* the block in front it and/or the block behind it if the memory blocks are | |
* adjacent to each other. | |
*/ | |
static void prvInsertBlockIntoFreeList( xBlockLink *pxBlockToInsert ); | |
/* | |
* Called automatically to setup the required heap structures the first time | |
* pvPortMalloc() is called. | |
*/ | |
static void prvHeapInit( void ); | |
/*-----------------------------------------------------------*/ | |
/* The size of the structure placed at the beginning of each allocated memory | |
block must by correctly byte aligned. */ | |
static const unsigned short heapSTRUCT_SIZE = ( sizeof( xBlockLink ) + portBYTE_ALIGNMENT - ( sizeof( xBlockLink ) % portBYTE_ALIGNMENT ) ); | |
/* Ensure the pxEnd pointer will end up on the correct byte alignment. */ | |
static const size_t xTotalHeapSize = ( ( size_t ) configTOTAL_HEAP_SIZE ) & ( ( size_t ) ~portBYTE_ALIGNMENT_MASK ); | |
/* Create a couple of list links to mark the start and end of the list. */ | |
static xBlockLink xStart, *pxEnd = NULL; | |
/* Keeps track of the number of free bytes remaining, but says nothing about | |
fragmentation. */ | |
static size_t xFreeBytesRemaining = ( ( size_t ) configTOTAL_HEAP_SIZE ) & ( ( size_t ) ~portBYTE_ALIGNMENT_MASK ); | |
/* STATIC FUNCTIONS ARE DEFINED AS MACROS TO MINIMIZE THE FUNCTION CALL DEPTH. */ | |
/*-----------------------------------------------------------*/ | |
void *pvPortMalloc( size_t xWantedSize ) | |
{ | |
xBlockLink *pxBlock, *pxPreviousBlock, *pxNewBlockLink; | |
void *pvReturn = NULL; | |
vTaskSuspendAll(); | |
{ | |
/* If this is the first call to malloc then the heap will require | |
initialisation to setup the list of free blocks. */ | |
if( pxEnd == NULL ) | |
{ | |
prvHeapInit(); | |
} | |
/* The wanted size is increased so it can contain a xBlockLink | |
structure in addition to the requested amount of bytes. */ | |
if( xWantedSize > 0 ) | |
{ | |
xWantedSize += heapSTRUCT_SIZE; | |
/* Ensure that blocks are always aligned to the required number of | |
bytes. */ | |
if( xWantedSize & portBYTE_ALIGNMENT_MASK ) | |
{ | |
/* Byte alignment required. */ | |
xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ); | |
} | |
} | |
if( ( xWantedSize > 0 ) && ( xWantedSize < xTotalHeapSize ) ) | |
{ | |
/* Traverse the list from the start (lowest address) 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 the end marker was reached then a block of adequate size was | |
not found. */ | |
if( pxBlock != pxEnd ) | |
{ | |
/* Return the memory space - jumping over the xBlockLink structure | |
at its start. */ | |
pvReturn = ( void * ) ( ( ( unsigned char * ) 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 * ) ( ( ( unsigned char * ) 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; | |
} | |
} | |
} | |
xTaskResumeAll(); | |
#if( configUSE_MALLOC_FAILED_HOOK == 1 ) | |
{ | |
if( pvReturn == NULL ) | |
{ | |
extern void vApplicationMallocFailedHook( void ); | |
vApplicationMallocFailedHook(); | |
} | |
} | |
#endif | |
return pvReturn; | |
} | |
/*-----------------------------------------------------------*/ | |
void vPortFree( void *pv ) | |
{ | |
unsigned char *puc = ( unsigned char * ) pv; | |
xBlockLink *pxLink; | |
if( pv != NULL ) | |
{ | |
/* The memory being freed will have an xBlockLink structure immediately | |
before it. */ | |
puc -= heapSTRUCT_SIZE; | |
/* This casting is to keep the compiler from issuing warnings. */ | |
pxLink = ( void * ) puc; | |
vTaskSuspendAll(); | |
{ | |
/* Add this block to the list of free blocks. */ | |
xFreeBytesRemaining += pxLink->xBlockSize; | |
prvInsertBlockIntoFreeList( ( ( xBlockLink * ) pxLink ) ); | |
} | |
xTaskResumeAll(); | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
size_t xPortGetFreeHeapSize( void ) | |
{ | |
return xFreeBytesRemaining; | |
} | |
/*-----------------------------------------------------------*/ | |
void vPortInitialiseBlocks( void ) | |
{ | |
/* This just exists to keep the linker quiet. */ | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvHeapInit( void ) | |
{ | |
xBlockLink *pxFirstFreeBlock; | |
unsigned char *pucHeapEnd; | |
/* Ensure the start of the heap is aligned. */ | |
configASSERT( ( ( ( unsigned long ) xHeap.ucHeap ) & ( ( unsigned long ) portBYTE_ALIGNMENT_MASK ) ) == 0UL ); | |
/* 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 * ) xHeap.ucHeap; | |
xStart.xBlockSize = ( size_t ) 0; | |
/* pxEnd is used to mark the end of the list of free blocks and is inserted | |
at the end of the heap space. */ | |
pucHeapEnd = xHeap.ucHeap + xTotalHeapSize; | |
pucHeapEnd -= heapSTRUCT_SIZE; | |
pxEnd = ( void * ) pucHeapEnd; | |
configASSERT( ( ( ( unsigned long ) pxEnd ) & ( ( unsigned long ) portBYTE_ALIGNMENT_MASK ) ) == 0UL ); | |
pxEnd->xBlockSize = 0; | |
pxEnd->pxNextFreeBlock = NULL; | |
/* To start with there is a single free block that is sized to take up the | |
entire heap space, minus the space taken by pxEnd. */ | |
pxFirstFreeBlock = ( void * ) xHeap.ucHeap; | |
pxFirstFreeBlock->xBlockSize = xTotalHeapSize - heapSTRUCT_SIZE; | |
pxFirstFreeBlock->pxNextFreeBlock = pxEnd; | |
/* The heap now contains pxEnd. */ | |
xFreeBytesRemaining -= heapSTRUCT_SIZE; | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvInsertBlockIntoFreeList( xBlockLink *pxBlockToInsert ) | |
{ | |
xBlockLink *pxIterator; | |
unsigned char *puc; | |
/* Iterate through the list until a block is found that has a higher address | |
than the block being inserted. */ | |
for( pxIterator = &xStart; pxIterator->pxNextFreeBlock < pxBlockToInsert; pxIterator = pxIterator->pxNextFreeBlock ) | |
{ | |
/* Nothing to do here, just iterate to the right position. */ | |
} | |
/* Do the block being inserted, and the block it is being inserted after | |
make a contiguous block of memory? */ | |
puc = ( unsigned char * ) pxIterator; | |
if( ( puc + pxIterator->xBlockSize ) == ( unsigned char * ) pxBlockToInsert ) | |
{ | |
pxIterator->xBlockSize += pxBlockToInsert->xBlockSize; | |
pxBlockToInsert = pxIterator; | |
} | |
/* Do the block being inserted, and the block it is being inserted before | |
make a contiguous block of memory? */ | |
puc = ( unsigned char * ) pxBlockToInsert; | |
if( ( puc + pxBlockToInsert->xBlockSize ) == ( unsigned char * ) pxIterator->pxNextFreeBlock ) | |
{ | |
if( pxIterator->pxNextFreeBlock != pxEnd ) | |
{ | |
/* Form one big block from the two blocks. */ | |
pxBlockToInsert->xBlockSize += pxIterator->pxNextFreeBlock->xBlockSize; | |
pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock->pxNextFreeBlock; | |
} | |
else | |
{ | |
pxBlockToInsert->pxNextFreeBlock = pxEnd; | |
} | |
} | |
else | |
{ | |
pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock; | |
} | |
/* If the block being inserted plugged a gab, so was merged with the block | |
before and the block after, then it's pxNextFreeBlock pointer will have | |
already been set, and should not be set here as that would make it point | |
to itself. */ | |
if( pxIterator != pxBlockToInsert ) | |
{ | |
pxIterator->pxNextFreeBlock = pxBlockToInsert; | |
} | |
} | |