2 FreeRTOS V8.1.2 - Copyright (C) 2014 Real Time Engineers Ltd.
\r
5 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
\r
7 ***************************************************************************
\r
9 * FreeRTOS provides completely free yet professionally developed, *
\r
10 * robust, strictly quality controlled, supported, and cross *
\r
11 * platform software that has become a de facto standard. *
\r
13 * Help yourself get started quickly and support the FreeRTOS *
\r
14 * project by purchasing a FreeRTOS tutorial book, reference *
\r
15 * manual, or both from: http://www.FreeRTOS.org/Documentation *
\r
19 ***************************************************************************
\r
21 This file is part of the FreeRTOS distribution.
\r
23 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
24 the terms of the GNU General Public License (version 2) as published by the
\r
25 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
\r
27 >>! NOTE: The modification to the GPL is included to allow you to !<<
\r
28 >>! distribute a combined work that includes FreeRTOS without being !<<
\r
29 >>! obliged to provide the source code for proprietary components !<<
\r
30 >>! outside of the FreeRTOS kernel. !<<
\r
32 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
\r
33 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
\r
34 FOR A PARTICULAR PURPOSE. Full license text is available from the following
\r
35 link: http://www.freertos.org/a00114.html
\r
39 ***************************************************************************
\r
41 * Having a problem? Start by reading the FAQ "My application does *
\r
42 * not run, what could be wrong?" *
\r
44 * http://www.FreeRTOS.org/FAQHelp.html *
\r
46 ***************************************************************************
\r
48 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
\r
49 license and Real Time Engineers Ltd. contact details.
\r
51 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
52 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
\r
53 compatible FAT file system, and our tiny thread aware UDP/IP stack.
\r
55 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
\r
56 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
\r
57 licenses offer ticketed support, indemnification and middleware.
\r
59 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
\r
60 engineered and independently SIL3 certified version for use in safety and
\r
61 mission critical applications that require provable dependability.
\r
67 * A sample implementation of pvPortMalloc() and vPortFree() that combines
\r
68 * (coalescences) adjacent memory blocks as they are freed, and in so doing
\r
69 * limits memory fragmentation.
\r
71 * See heap_1.c, heap_2.c and heap_3.c for alternative implementations, and the
\r
72 * memory management pages of http://www.FreeRTOS.org for more information.
\r
76 /* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
\r
77 all the API functions to use the MPU wrappers. That should only be done when
\r
78 task.h is included from an application file. */
\r
79 #define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
\r
81 #include "FreeRTOS.h"
\r
84 #undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
\r
86 /* Block sizes must not get too small. */
\r
87 #define heapMINIMUM_BLOCK_SIZE ( ( size_t ) ( xHeapStructSize * 2 ) )
\r
89 /* Assumes 8bit bytes! */
\r
90 #define heapBITS_PER_BYTE ( ( size_t ) 8 )
\r
92 /* Allocate the memory for the heap. */
\r
93 static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
\r
95 /* Define the linked list structure. This is used to link free blocks in order
\r
96 of their memory address. */
\r
97 typedef struct A_BLOCK_LINK
\r
99 struct A_BLOCK_LINK *pxNextFreeBlock; /*<< The next free block in the list. */
\r
100 size_t xBlockSize; /*<< The size of the free block. */
\r
103 /*-----------------------------------------------------------*/
\r
106 * Inserts a block of memory that is being freed into the correct position in
\r
107 * the list of free memory blocks. The block being freed will be merged with
\r
108 * the block in front it and/or the block behind it if the memory blocks are
\r
109 * adjacent to each other.
\r
111 static void prvInsertBlockIntoFreeList( BlockLink_t *pxBlockToInsert );
\r
114 * Called automatically to setup the required heap structures the first time
\r
115 * pvPortMalloc() is called.
\r
117 static void prvHeapInit( void );
\r
119 /*-----------------------------------------------------------*/
\r
121 /* The size of the structure placed at the beginning of each allocated memory
\r
122 block must by correctly byte aligned. */
\r
123 static const size_t xHeapStructSize = ( ( sizeof( BlockLink_t ) + ( portBYTE_ALIGNMENT - 1 ) ) & ~portBYTE_ALIGNMENT_MASK );
\r
125 /* Create a couple of list links to mark the start and end of the list. */
\r
126 static BlockLink_t xStart, *pxEnd = NULL;
\r
128 /* Keeps track of the number of free bytes remaining, but says nothing about
\r
130 static size_t xFreeBytesRemaining = 0U;
\r
131 static size_t xMinimumEverFreeBytesRemaining = 0U;
\r
133 /* Gets set to the top bit of an size_t type. When this bit in the xBlockSize
\r
134 member of an BlockLink_t structure is set then the block belongs to the
\r
135 application. When the bit is free the block is still part of the free heap
\r
137 static size_t xBlockAllocatedBit = 0;
\r
139 /*-----------------------------------------------------------*/
\r
141 void *pvPortMalloc( size_t xWantedSize )
\r
143 BlockLink_t *pxBlock, *pxPreviousBlock, *pxNewBlockLink;
\r
144 void *pvReturn = NULL;
\r
148 /* If this is the first call to malloc then the heap will require
\r
149 initialisation to setup the list of free blocks. */
\r
150 if( pxEnd == NULL )
\r
156 mtCOVERAGE_TEST_MARKER();
\r
159 /* Check the requested block size is not so large that the top bit is
\r
160 set. The top bit of the block size member of the BlockLink_t structure
\r
161 is used to determine who owns the block - the application or the
\r
162 kernel, so it must be free. */
\r
163 if( ( xWantedSize & xBlockAllocatedBit ) == 0 )
\r
165 /* The wanted size is increased so it can contain a BlockLink_t
\r
166 structure in addition to the requested amount of bytes. */
\r
167 if( xWantedSize > 0 )
\r
169 xWantedSize += xHeapStructSize;
\r
171 /* Ensure that blocks are always aligned to the required number
\r
173 if( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) != 0x00 )
\r
175 /* Byte alignment required. */
\r
176 xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
\r
177 configASSERT( ( xWantedSize & portBYTE_ALIGNMENT_MASK ) == 0 );
\r
181 mtCOVERAGE_TEST_MARKER();
\r
186 mtCOVERAGE_TEST_MARKER();
\r
189 if( ( xWantedSize > 0 ) && ( xWantedSize <= xFreeBytesRemaining ) )
\r
191 /* Traverse the list from the start (lowest address) block until
\r
192 one of adequate size is found. */
\r
193 pxPreviousBlock = &xStart;
\r
194 pxBlock = xStart.pxNextFreeBlock;
\r
195 while( ( pxBlock->xBlockSize < xWantedSize ) && ( pxBlock->pxNextFreeBlock != NULL ) )
\r
197 pxPreviousBlock = pxBlock;
\r
198 pxBlock = pxBlock->pxNextFreeBlock;
\r
201 /* If the end marker was reached then a block of adequate size
\r
203 if( pxBlock != pxEnd )
\r
205 /* Return the memory space pointed to - jumping over the
\r
206 BlockLink_t structure at its start. */
\r
207 pvReturn = ( void * ) ( ( ( uint8_t * ) pxPreviousBlock->pxNextFreeBlock ) + xHeapStructSize );
\r
209 /* This block is being returned for use so must be taken out
\r
210 of the list of free blocks. */
\r
211 pxPreviousBlock->pxNextFreeBlock = pxBlock->pxNextFreeBlock;
\r
213 /* If the block is larger than required it can be split into
\r
215 if( ( pxBlock->xBlockSize - xWantedSize ) > heapMINIMUM_BLOCK_SIZE )
\r
217 /* This block is to be split into two. Create a new
\r
218 block following the number of bytes requested. The void
\r
219 cast is used to prevent byte alignment warnings from the
\r
221 pxNewBlockLink = ( void * ) ( ( ( uint8_t * ) pxBlock ) + xWantedSize );
\r
222 configASSERT( ( ( ( uint32_t ) pxNewBlockLink ) & portBYTE_ALIGNMENT_MASK ) == 0 );
\r
224 /* Calculate the sizes of two blocks split from the
\r
226 pxNewBlockLink->xBlockSize = pxBlock->xBlockSize - xWantedSize;
\r
227 pxBlock->xBlockSize = xWantedSize;
\r
229 /* Insert the new block into the list of free blocks. */
\r
230 prvInsertBlockIntoFreeList( ( pxNewBlockLink ) );
\r
234 mtCOVERAGE_TEST_MARKER();
\r
237 xFreeBytesRemaining -= pxBlock->xBlockSize;
\r
239 if( xFreeBytesRemaining < xMinimumEverFreeBytesRemaining )
\r
241 xMinimumEverFreeBytesRemaining = xFreeBytesRemaining;
\r
245 mtCOVERAGE_TEST_MARKER();
\r
248 /* The block is being returned - it is allocated and owned
\r
249 by the application and has no "next" block. */
\r
250 pxBlock->xBlockSize |= xBlockAllocatedBit;
\r
251 pxBlock->pxNextFreeBlock = NULL;
\r
255 mtCOVERAGE_TEST_MARKER();
\r
260 mtCOVERAGE_TEST_MARKER();
\r
265 mtCOVERAGE_TEST_MARKER();
\r
268 traceMALLOC( pvReturn, xWantedSize );
\r
270 ( void ) xTaskResumeAll();
\r
272 #if( configUSE_MALLOC_FAILED_HOOK == 1 )
\r
274 if( pvReturn == NULL )
\r
276 extern void vApplicationMallocFailedHook( void );
\r
277 vApplicationMallocFailedHook();
\r
281 mtCOVERAGE_TEST_MARKER();
\r
286 configASSERT( ( ( ( uint32_t ) pvReturn ) & portBYTE_ALIGNMENT_MASK ) == 0 );
\r
289 /*-----------------------------------------------------------*/
\r
291 void vPortFree( void *pv )
\r
293 uint8_t *puc = ( uint8_t * ) pv;
\r
294 BlockLink_t *pxLink;
\r
298 /* The memory being freed will have an BlockLink_t structure immediately
\r
300 puc -= xHeapStructSize;
\r
302 /* This casting is to keep the compiler from issuing warnings. */
\r
303 pxLink = ( void * ) puc;
\r
305 /* Check the block is actually allocated. */
\r
306 configASSERT( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 );
\r
307 configASSERT( pxLink->pxNextFreeBlock == NULL );
\r
309 if( ( pxLink->xBlockSize & xBlockAllocatedBit ) != 0 )
\r
311 if( pxLink->pxNextFreeBlock == NULL )
\r
313 /* The block is being returned to the heap - it is no longer
\r
315 pxLink->xBlockSize &= ~xBlockAllocatedBit;
\r
319 /* Add this block to the list of free blocks. */
\r
320 xFreeBytesRemaining += pxLink->xBlockSize;
\r
321 traceFREE( pv, pxLink->xBlockSize );
\r
322 prvInsertBlockIntoFreeList( ( ( BlockLink_t * ) pxLink ) );
\r
324 ( void ) xTaskResumeAll();
\r
328 mtCOVERAGE_TEST_MARKER();
\r
333 mtCOVERAGE_TEST_MARKER();
\r
337 /*-----------------------------------------------------------*/
\r
339 size_t xPortGetFreeHeapSize( void )
\r
341 return xFreeBytesRemaining;
\r
343 /*-----------------------------------------------------------*/
\r
345 size_t xPortGetMinimumEverFreeHeapSize( void )
\r
347 return xMinimumEverFreeBytesRemaining;
\r
349 /*-----------------------------------------------------------*/
\r
351 void vPortInitialiseBlocks( void )
\r
353 /* This just exists to keep the linker quiet. */
\r
355 /*-----------------------------------------------------------*/
\r
357 static void prvHeapInit( void )
\r
359 BlockLink_t *pxFirstFreeBlock;
\r
360 uint8_t *pucAlignedHeap;
\r
361 uint32_t ulAddress;
\r
362 size_t xTotalHeapSize = configTOTAL_HEAP_SIZE;
\r
364 /* Ensure the heap starts on a correctly aligned boundary. */
\r
365 ulAddress = ( uint32_t ) ucHeap;
\r
367 if( ( ulAddress & portBYTE_ALIGNMENT_MASK ) != 0 )
\r
369 ulAddress += ( portBYTE_ALIGNMENT - 1 );
\r
370 ulAddress &= ~portBYTE_ALIGNMENT_MASK;
\r
371 xTotalHeapSize -= ulAddress - ( uint32_t ) ucHeap;
\r
374 pucAlignedHeap = ( uint8_t * ) ulAddress;
\r
376 /* xStart is used to hold a pointer to the first item in the list of free
\r
377 blocks. The void cast is used to prevent compiler warnings. */
\r
378 xStart.pxNextFreeBlock = ( void * ) pucAlignedHeap;
\r
379 xStart.xBlockSize = ( size_t ) 0;
\r
381 /* pxEnd is used to mark the end of the list of free blocks and is inserted
\r
382 at the end of the heap space. */
\r
383 ulAddress = ( ( uint32_t ) pucAlignedHeap ) + xTotalHeapSize;
\r
384 ulAddress -= xHeapStructSize;
\r
385 ulAddress &= ~portBYTE_ALIGNMENT_MASK;
\r
386 pxEnd = ( void * ) ulAddress;
\r
387 pxEnd->xBlockSize = 0;
\r
388 pxEnd->pxNextFreeBlock = NULL;
\r
390 /* To start with there is a single free block that is sized to take up the
\r
391 entire heap space, minus the space taken by pxEnd. */
\r
392 pxFirstFreeBlock = ( void * ) pucAlignedHeap;
\r
393 pxFirstFreeBlock->xBlockSize = ulAddress - ( uint32_t ) pxFirstFreeBlock;
\r
394 pxFirstFreeBlock->pxNextFreeBlock = pxEnd;
\r
396 /* Only one block exists - and it covers the entire usable heap space. */
\r
397 xMinimumEverFreeBytesRemaining = pxFirstFreeBlock->xBlockSize;
\r
398 xFreeBytesRemaining = pxFirstFreeBlock->xBlockSize;
\r
400 /* Work out the position of the top bit in a size_t variable. */
\r
401 xBlockAllocatedBit = ( ( size_t ) 1 ) << ( ( sizeof( size_t ) * heapBITS_PER_BYTE ) - 1 );
\r
403 /*-----------------------------------------------------------*/
\r
405 static void prvInsertBlockIntoFreeList( BlockLink_t *pxBlockToInsert )
\r
407 BlockLink_t *pxIterator;
\r
410 /* Iterate through the list until a block is found that has a higher address
\r
411 than the block being inserted. */
\r
412 for( pxIterator = &xStart; pxIterator->pxNextFreeBlock < pxBlockToInsert; pxIterator = pxIterator->pxNextFreeBlock )
\r
414 /* Nothing to do here, just iterate to the right position. */
\r
417 /* Do the block being inserted, and the block it is being inserted after
\r
418 make a contiguous block of memory? */
\r
419 puc = ( uint8_t * ) pxIterator;
\r
420 if( ( puc + pxIterator->xBlockSize ) == ( uint8_t * ) pxBlockToInsert )
\r
422 pxIterator->xBlockSize += pxBlockToInsert->xBlockSize;
\r
423 pxBlockToInsert = pxIterator;
\r
427 mtCOVERAGE_TEST_MARKER();
\r
430 /* Do the block being inserted, and the block it is being inserted before
\r
431 make a contiguous block of memory? */
\r
432 puc = ( uint8_t * ) pxBlockToInsert;
\r
433 if( ( puc + pxBlockToInsert->xBlockSize ) == ( uint8_t * ) pxIterator->pxNextFreeBlock )
\r
435 if( pxIterator->pxNextFreeBlock != pxEnd )
\r
437 /* Form one big block from the two blocks. */
\r
438 pxBlockToInsert->xBlockSize += pxIterator->pxNextFreeBlock->xBlockSize;
\r
439 pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock->pxNextFreeBlock;
\r
443 pxBlockToInsert->pxNextFreeBlock = pxEnd;
\r
448 pxBlockToInsert->pxNextFreeBlock = pxIterator->pxNextFreeBlock;
\r
451 /* If the block being inserted plugged a gab, so was merged with the block
\r
452 before and the block after, then it's pxNextFreeBlock pointer will have
\r
453 already been set, and should not be set here as that would make it point
\r
455 if( pxIterator != pxBlockToInsert )
\r
457 pxIterator->pxNextFreeBlock = pxBlockToInsert;
\r
461 mtCOVERAGE_TEST_MARKER();
\r