heap_1.c

00001 /*
00002     FreeRTOS V8.2.1 - Copyright (C) 2015 Real Time Engineers Ltd.
00003     All rights reserved
00004 
00005     VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
00006 
00007     This file is part of the FreeRTOS distribution.
00008 
00009     FreeRTOS is free software; you can redistribute it and/or modify it under
00010     the terms of the GNU General Public License (version 2) as published by the
00011     Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
00012 
00013     ***************************************************************************
00014     >>!   NOTE: The modification to the GPL is included to allow you to     !<<
00015     >>!   distribute a combined work that includes FreeRTOS without being   !<<
00016     >>!   obliged to provide the source code for proprietary components     !<<
00017     >>!   outside of the FreeRTOS kernel.                                   !<<
00018     ***************************************************************************
00019 
00020     FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
00021     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
00022     FOR A PARTICULAR PURPOSE.  Full license text is available on the following
00023     link: http://www.freertos.org/a00114.html
00024 
00025     ***************************************************************************
00026      *                                                                       *
00027      *    FreeRTOS provides completely free yet professionally developed,    *
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00030      *    is the industry's de facto standard.                               *
00031      *                                                                       *
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00038 
00039     http://www.FreeRTOS.org/FAQHelp.html - Having a problem?  Start by reading
00040     the FAQ page "My application does not run, what could be wrong?".  Have you
00041     defined configASSERT()?
00042 
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00055 
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00058 
00059     http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
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00064     engineered and independently SIL3 certified version for use in safety and
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00066 
00067     1 tab == 4 spaces!
00068 */
00069 
00070 
00071 /*
00072  * The simplest possible implementation of pvPortMalloc().  Note that this
00073  * implementation does NOT allow allocated memory to be freed again.
00074  *
00075  * See heap_2.c, heap_3.c and heap_4.c for alternative implementations, and the
00076  * memory management pages of http://www.FreeRTOS.org for more information.
00077  */
00078 #include <stdlib.h>
00079 
00080 /* Defining MPU_WRAPPERS_INCLUDED_FROM_API_FILE prevents task.h from redefining
00081 all the API functions to use the MPU wrappers.  That should only be done when
00082 task.h is included from an application file. */
00083 #define MPU_WRAPPERS_INCLUDED_FROM_API_FILE
00084 
00085 #include "FreeRTOS.h"
00086 #include "task.h"
00087 
00088 #undef MPU_WRAPPERS_INCLUDED_FROM_API_FILE
00089 
00090 /* A few bytes might be lost to byte aligning the heap start address. */
00091 #define configADJUSTED_HEAP_SIZE    ( configTOTAL_HEAP_SIZE - portBYTE_ALIGNMENT )
00092 
00093 /* Allocate the memory for the heap. */
00094 static uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];
00095 static size_t xNextFreeByte = ( size_t ) 0;
00096 
00097 /*-----------------------------------------------------------*/
00098 
00099 void *pvPortMalloc( size_t xWantedSize )
00100 {
00101 void *pvReturn = NULL;
00102 static uint8_t *pucAlignedHeap = NULL;
00103 
00104     /* Ensure that blocks are always aligned to the required number of bytes. */
00105     #if portBYTE_ALIGNMENT != 1
00106         if( xWantedSize & portBYTE_ALIGNMENT_MASK )
00107         {
00108             /* Byte alignment required. */
00109             xWantedSize += ( portBYTE_ALIGNMENT - ( xWantedSize & portBYTE_ALIGNMENT_MASK ) );
00110         }
00111     #endif
00112 
00113     vTaskSuspendAll();
00114     {
00115         if( pucAlignedHeap == NULL )
00116         {
00117             /* Ensure the heap starts on a correctly aligned boundary. */
00118             pucAlignedHeap = ( uint8_t * ) ( ( ( portPOINTER_SIZE_TYPE ) &ucHeap[ portBYTE_ALIGNMENT ] ) & ( ~( ( portPOINTER_SIZE_TYPE ) portBYTE_ALIGNMENT_MASK ) ) );
00119         }
00120 
00121         /* Check there is enough room left for the allocation. */
00122         if( ( ( xNextFreeByte + xWantedSize ) < configADJUSTED_HEAP_SIZE ) &&
00123             ( ( xNextFreeByte + xWantedSize ) > xNextFreeByte ) )/* Check for overflow. */
00124         {
00125             /* Return the next free byte then increment the index past this
00126             block. */
00127             pvReturn = pucAlignedHeap + xNextFreeByte;
00128             xNextFreeByte += xWantedSize;
00129         }
00130 
00131         traceMALLOC( pvReturn, xWantedSize );
00132     }
00133     ( void ) xTaskResumeAll();
00134 
00135     #if( configUSE_MALLOC_FAILED_HOOK == 1 )
00136     {
00137         if( pvReturn == NULL )
00138         {
00139             extern void vApplicationMallocFailedHook( void );
00140             vApplicationMallocFailedHook();
00141         }
00142     }
00143     #endif
00144 
00145     return pvReturn;
00146 }
00147 /*-----------------------------------------------------------*/
00148 
00149 void vPortFree( void *pv )
00150 {
00151     /* Memory cannot be freed using this scheme.  See heap_2.c, heap_3.c and
00152     heap_4.c for alternative implementations, and the memory management pages of
00153     http://www.FreeRTOS.org for more information. */
00154     ( void ) pv;
00155 
00156     /* Force an assert as it is invalid to call this function. */
00157     configASSERT( pv == NULL );
00158 }
00159 /*-----------------------------------------------------------*/
00160 
00161 void vPortInitialiseBlocks( void )
00162 {
00163     /* Only required when static memory is not cleared. */
00164     xNextFreeByte = ( size_t ) 0;
00165 }
00166 /*-----------------------------------------------------------*/
00167 
00168 size_t xPortGetFreeHeapSize( void )
00169 {
00170     return ( configADJUSTED_HEAP_SIZE - xNextFreeByte );
00171 }
00172 
00173 
00174 
00175