diff options
Diffstat (limited to 'freertos/src/portable/MemMang/heap_4.c')
| -rw-r--r-- | freertos/src/portable/MemMang/heap_4.c | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/freertos/src/portable/MemMang/heap_4.c b/freertos/src/portable/MemMang/heap_4.c new file mode 100644 index 0000000..e7c7ade --- /dev/null +++ b/freertos/src/portable/MemMang/heap_4.c @@ -0,0 +1,478 @@ +/* + FreeRTOS V9.0.0 - Copyright (C) 2016 Real Time Engineers Ltd. + All rights reserved + + VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. + + 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 on the following + link: http://www.freertos.org/a00114.html + + *************************************************************************** + * * + * FreeRTOS provides completely free yet professionally developed, * + * robust, strictly quality controlled, supported, and cross * + * platform software that is more than just the market leader, it * + * is the industry's de facto standard. * + * * + * Help yourself get started quickly while simultaneously helping * + * to support the FreeRTOS project by purchasing a FreeRTOS * + * tutorial book, reference manual, or both: * + * http://www.FreeRTOS.org/Documentation * + * * + *************************************************************************** + + http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading + the FAQ page "My application does not run, what could be wrong?". Have you + defined configASSERT()? + + http://www.FreeRTOS.org/support - In return for receiving this top quality + embedded software for free we request you assist our global community by + participating in the support forum. + + http://www.FreeRTOS.org/training - Investing in training allows your team to + be as productive as possible as early as possible. Now you can receive + FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers + Ltd, and the world's leading authority on the world's leading RTOS. + + 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.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate. + Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS. + + http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High + Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS + licenses offer ticketed support, indemnification and commercial 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 + +#if( configSUPPORT_DYNAMIC_ALLOCATION == 0 ) + #error This file must not be used if configSUPPORT_DYNAMIC_ALLOCATION is 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 ) + +/* 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 + 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 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 size_t xHeapStructSize = ( sizeof( BlockLink_t ) + ( ( size_t ) ( portBYTE_ALIGNMENT - 1 ) ) ) & ~( ( 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 = 0U; +static size_t xMinimumEverFreeBytesRemaining = 0U; + +/* 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 += xHeapStructSize; + + /* 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 ) ); + configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 ); + } + 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 ) + 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 ); + configASSERT( ( ( ( size_t ) pxNewBlockLink ) & portBYTE_ALIGNMENT_MASK ) == 0 ); + + /* 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 ); + } + ( void ) xTaskResumeAll(); + + #if( configUSE_MALLOC_FAILED_HOOK == 1 ) + { + if( pvReturn == NULL ) + { + extern void vApplicationMallocFailedHook( void ); + vApplicationMallocFailedHook(); + } + else + { + mtCOVERAGE_TEST_MARKER(); + } + } + #endif + + configASSERT( ( ( ( size_t ) pvReturn ) & ( size_t ) portBYTE_ALIGNMENT_MASK ) == 0 ); + 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 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 ) ); + } + ( void ) 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 *pucAlignedHeap; +size_t uxAddress; +size_t xTotalHeapSize = configTOTAL_HEAP_SIZE; + + /* Ensure the heap starts on a correctly aligned boundary. */ + uxAddress = ( size_t ) ucHeap; + + if( ( uxAddress & portBYTE_ALIGNMENT_MASK ) != 0 ) + { + uxAddress += ( portBYTE_ALIGNMENT - 1 ); + uxAddress &= ~( ( size_t ) portBYTE_ALIGNMENT_MASK ); + xTotalHeapSize -= uxAddress - ( size_t ) ucHeap; + } + + pucAlignedHeap = ( uint8_t * ) uxAddress; + + /* 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. */ + uxAddress = ( ( size_t ) pucAlignedHeap ) + xTotalHeapSize; + uxAddress -= xHeapStructSize; + uxAddress &= ~( ( size_t ) portBYTE_ALIGNMENT_MASK ); + pxEnd = ( void * ) uxAddress; + 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 = uxAddress - ( size_t ) pxFirstFreeBlock; + pxFirstFreeBlock->pxNextFreeBlock = pxEnd; + + /* 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 ); +} +/*-----------------------------------------------------------*/ + +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(); + } +} + |