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Diffstat (limited to 'rtos/FreeRTOS/Source/portable/MemMang/heap_4.c')
-rw-r--r-- | rtos/FreeRTOS/Source/portable/MemMang/heap_4.c | 455 |
1 files changed, 455 insertions, 0 deletions
diff --git a/rtos/FreeRTOS/Source/portable/MemMang/heap_4.c b/rtos/FreeRTOS/Source/portable/MemMang/heap_4.c new file mode 100644 index 0000000..64d9622 --- /dev/null +++ b/rtos/FreeRTOS/Source/portable/MemMang/heap_4.c @@ -0,0 +1,455 @@ +/* + FreeRTOS V8.0.0 - Copyright (C) 2014 Real Time Engineers Ltd. + All rights reserved + + VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. + + *************************************************************************** + * * + * FreeRTOS provides completely free yet professionally developed, * + * robust, strictly quality controlled, supported, and cross * + * platform software that has become a de facto standard. * + * * + * Help yourself get started quickly and support the FreeRTOS * + * project by purchasing a FreeRTOS tutorial book, reference * + * manual, or both from: http://www.FreeRTOS.org/Documentation * + * * + * Thank you! * + * * + *************************************************************************** + + 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. Full license text is available from the following + link: http://www.freertos.org/a00114.html + + 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, books, training, latest versions, + license and Real Time Engineers Ltd. contact details. + + http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, + including FreeRTOS+Trace - an indispensable productivity tool, a DOS + compatible FAT file system, and our tiny thread aware UDP/IP stack. + + http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High + Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS + licenses offer ticketed support, indemnification and middleware. + + http://www.SafeRTOS.com - High Integrity Systems also provide a safety + engineered and independently SIL3 certified version for use in safety and + mission critical applications that require provable dependability. + + 1 tab == 4 spaces! +*/ + +/* + * 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 ) ) + +/* Assumes 8bit bytes! */ +#define heapBITS_PER_BYTE ( ( size_t ) 8 ) + +/* A few bytes might be lost to byte aligning the heap start address. */ +#define heapADJUSTED_HEAP_SIZE ( configTOTAL_HEAP_SIZE - portBYTE_ALIGNMENT ) + +/* Allocate the memory for the heap. */ +static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ]; + +/* 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. */ +} BlockLink_t; + +/*-----------------------------------------------------------*/ + +/* + * 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( BlockLink_t *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 uint16_t heapSTRUCT_SIZE = ( ( sizeof ( BlockLink_t ) + ( portBYTE_ALIGNMENT - 1 ) ) & ~portBYTE_ALIGNMENT_MASK ); + +/* Ensure the pxEnd pointer will end up on the correct byte alignment. */ +static const size_t xTotalHeapSize = ( ( size_t ) heapADJUSTED_HEAP_SIZE ) & ( ( size_t ) ~portBYTE_ALIGNMENT_MASK ); + +/* Create a couple of list links to mark the start and end of the list. */ +static BlockLink_t xStart, *pxEnd = NULL; + +/* Keeps track of the number of free bytes remaining, but says nothing about +fragmentation. */ +static size_t xFreeBytesRemaining = ( ( size_t ) heapADJUSTED_HEAP_SIZE ) & ( ( size_t ) ~portBYTE_ALIGNMENT_MASK ); +static size_t xMinimumEverFreeBytesRemaining = ( ( size_t ) heapADJUSTED_HEAP_SIZE ) & ( ( size_t ) ~portBYTE_ALIGNMENT_MASK ); + +/* 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 ) +{ +BlockLink_t *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(); + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + + /* 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( ( xWantedSize & xBlockAllocatedBit ) == 0 ) + { + /* The wanted size is increased so it can contain a BlockLink_t + 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 ) != 0x00 ) + { + /* Byte alignment required. */ + xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) ); + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + + if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) ) + { + /* 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 pointed to - 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 ) ); + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + + xFreeBytesRemaining -= pxBlock->xBlockSize; + + if( xFreeBytesRemaining < xMinimumEverFreeBytesRemaining ) + { + xMinimumEverFreeBytesRemaining = xFreeBytesRemaining; + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + + /* The block is being returned - it is allocated and owned + by the application and has no "next" block. */ + pxBlock->xBlockSize |= xBlockAllocatedBit; + pxBlock->pxNextFreeBlock = NULL; + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + + traceMALLOC( pvReturn, xWantedSize ); + } + xTaskResumeAll(); + + #if( configUSE_MALLOC_FAILED_HOOK == 1 ) + { + if( pvReturn == NULL ) + { + extern void vApplicationMallocFailedHook( void ); + vApplicationMallocFailedHook(); + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + } + #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 casting is to keep the compiler from issuing warnings. */ + pxLink = ( void * ) puc; + + /* Check the block is actually allocated. */ + configASSERT( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 ); + configASSERT( pxLink->pxNextFreeBlock == NULL ); + + if( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 ) + { + if( pxLink->pxNextFreeBlock == NULL ) + { + /* The block is being returned to the heap - it is no longer + allocated. */ + pxLink->xBlockSize &= ~xBlockAllocatedBit; + + vTaskSuspendAll(); + { + /* Add this block to the list of free blocks. */ + xFreeBytesRemaining += pxLink->xBlockSize; + traceFREE( pv, pxLink->xBlockSize ); + prvInsertBlockIntoFreeList( ( ( BlockLink_t * ) pxLink ) ); + } + xTaskResumeAll(); + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + } +} +/*-----------------------------------------------------------*/ + +size_t xPortGetFreeHeapSize( void ) +{ + return xFreeBytesRemaining; +} +/*-----------------------------------------------------------*/ + +size_t xPortGetMinimumEverFreeHeapSize( void ) +{ + return xMinimumEverFreeBytesRemaining; +} +/*-----------------------------------------------------------*/ + +void vPortInitialiseBlocks( void ) +{ + /* This just exists to keep the linker quiet. */ +} +/*-----------------------------------------------------------*/ + +static void prvHeapInit( void ) +{ +BlockLink_t *pxFirstFreeBlock; +uint8_t *pucHeapEnd, *pucAlignedHeap; + + /* Ensure the heap starts on a correctly aligned boundary. */ + pucAlignedHeap = ( uint8_t * ) ( ( ( portPOINTER_SIZE_TYPE ) &ucHeap[ portBYTE_ALIGNMENT ] ) & ( ( 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; + + /* pxEnd is used to mark the end of the list of free blocks and is inserted + at the end of the heap space. */ + pucHeapEnd = pucAlignedHeap + xTotalHeapSize; + pucHeapEnd -= heapSTRUCT_SIZE; + pxEnd = ( void * ) pucHeapEnd; + configASSERT( ( ( ( uint32_t ) pxEnd ) & ( ( uint32_t ) 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 * ) pucAlignedHeap; + pxFirstFreeBlock->xBlockSize = xTotalHeapSize - heapSTRUCT_SIZE; + pxFirstFreeBlock->pxNextFreeBlock = pxEnd; + + /* The heap now contains pxEnd. */ + xFreeBytesRemaining -= heapSTRUCT_SIZE; + + /* Work out the position of the top bit in a size_t variable. */ + xBlockAllocatedBit = ( ( size_t ) 1 ) << ( ( sizeof( size_t ) * heapBITS_PER_BYTE ) - 1 ); +} +/*-----------------------------------------------------------*/ + +static void prvInsertBlockIntoFreeList( BlockLink_t *pxBlockToInsert ) +{ +BlockLink_t *pxIterator; +uint8_t *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 = ( uint8_t * ) pxIterator; + if( ( puc + pxIterator->xBlockSize ) == ( uint8_t * ) pxBlockToInsert ) + { + pxIterator->xBlockSize += pxBlockToInsert->xBlockSize; + pxBlockToInsert = pxIterator; + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + + /* Do the block being inserted, and the block it is being inserted before + make a contiguous block of memory? */ + puc = ( uint8_t * ) pxBlockToInsert; + if( ( puc + pxBlockToInsert->xBlockSize ) == ( uint8_t * ) 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; + } + else + { + mtCOVERAGE_TEST_MARKER(); + } +} + |