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Add thread-safe memory manager using C runtime (Newlib)
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‎portable/MemMang/heap_newlib.c

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/**
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* \file heap_useNewlib.c
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* \brief Wrappers required to use newlib malloc-family within FreeRTOS.
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*
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* \par Overview
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* Route FreeRTOS memory management functions to newlib's malloc family.
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* Thus newlib and FreeRTOS share memory-management routines and memory pool,
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* and all newlib's internal memory-management requirements are supported.
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*
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* \author Dave Nadler
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* \date 2-July-2017
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*
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* \see http://www.nadler.com/embedded/newlibAndFreeRTOS.html
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* \see https://sourceware.org/newlib/libc.html#Reentrancy
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* \see https://sourceware.org/newlib/libc.html#malloc
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* \see https://sourceware.org/newlib/libc.html#index-_005f_005fenv_005flock
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* \see https://sourceware.org/newlib/libc.html#index-_005f_005fmalloc_005flock
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* \see https://sourceforge.net/p/freertos/feature-requests/72/
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* \see http://www.billgatliff.com/newlib.html
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* \see http://wiki.osdev.org/Porting_Newlib
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* \see http://www.embecosm.com/appnotes/ean9/ean9-howto-newlib-1.0.html
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*
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*
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* \copyright
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* (c) Dave Nadler 2017, All Rights Reserved.
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* Web: http://www.nadler.com
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* email: [email protected]
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* - Use or redistributions of source code must retain the above copyright notice,
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* this list of conditions, ALL ORIGINAL COMMENTS, and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright notice, this
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* list of conditions and the following disclaimer in the documentation and/or
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* other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
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* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <stdlib.h> // maps to newlib...
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#include <malloc.h> // mallinfo...
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#include <errno.h> // ENOMEM
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#include "newlib.h"
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#if (__NEWLIB__ != 2) || (__NEWLIB_MINOR__ != 5)
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#warning "This wrapper was verified for newlib version 2.5.0; please ensure newlib's external requirements for malloc-family are unchanged!"
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#endif
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#include "freeRTOS.h" // defines public interface we're implementing here
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#if !defined(configUSE_NEWLIB_REENTRANT) || (configUSE_NEWLIB_REENTRANT!=1)
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#warning "#define configUSE_NEWLIB_REENTRANT 1 // Required for thread-safety of newlib sprintf, strtok, etc..."
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// If you're *really* sure you don't need FreeRTOS's newlib reentrancy support, remove this warning...
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#endif
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#include "task.h"
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// ================================================================================================
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// External routines required by newlib's malloc (sbrk/_sbrk, __malloc_lock/unlock)
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// ================================================================================================
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#ifndef NDEBUG
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static int totalBytesProvidedBySBRK = 0;
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#endif
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extern char _end; // make sure to define these symbols in linker command file
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static int heapBytesRemaining = configTOTAL_HEAP_SIZE; // that's (&__HeapLimit)-(&__HeapBase)
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//! sbrk/_sbrk version supporting reentrant newlib (depends upon above symbols defined by linker control file).
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char * sbrk(int incr) {
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static char *currentHeapEnd = &_end;
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vTaskSuspendAll(); // Note: safe to use before FreeRTOS scheduler started
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char *previousHeapEnd = currentHeapEnd;
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if (currentHeapEnd + incr > &_end + configTOTAL_HEAP_SIZE) {
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#if( configUSE_MALLOC_FAILED_HOOK == 1 )
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{
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extern void vApplicationMallocFailedHook( void );
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vApplicationMallocFailedHook();
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}
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#elif 0
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// If you want to alert debugger or halt...
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while(1) { __asm("bkpt #0"); }; // Stop in GUI as if at a breakpoint (if debugging, otherwise loop forever)
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#else
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// If you prefer to believe your application will gracefully trap out-of-memory...
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_impure_ptr->_errno = ENOMEM; // newlib's thread-specific errno
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xTaskResumeAll();
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#endif
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return (char *)-1; // the malloc-family routine that called sbrk will return 0
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}
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currentHeapEnd += incr;
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heapBytesRemaining -= incr;
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#ifndef NDEBUG
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totalBytesProvidedBySBRK += incr;
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#endif
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xTaskResumeAll();
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return (char *) previousHeapEnd;
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}
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//! Synonym for sbrk.
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char * _sbrk(int incr) { return sbrk(incr); };
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void __malloc_lock() { vTaskSuspendAll(); };
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void __malloc_unlock() { (void)xTaskResumeAll(); };
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// newlib also requires implementing locks for the application's environment memory space,
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// accessed by newlib's setenv() and getenv() functions.
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// As these are trivial functions, momentarily suspend task switching (rather than semaphore).
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// ToDo: Move __env_lock/unlock to a separate newlib helper file.
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void __env_lock() { vTaskSuspendAll(); };
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void __env_unlock() { (void)xTaskResumeAll(); };
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/// /brief Wrap malloc/malloc_r to help debug who requests memory and why.
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/// Add to the linker command line: -Xlinker --wrap=malloc -Xlinker --wrap=_malloc_r
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// Note: These functions are normally unused and stripped by linker.
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void *__wrap_malloc(size_t nbytes) {
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extern void * __real_malloc(size_t nbytes);
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void *p = __real_malloc(nbytes); // Solely for debug breakpoint...
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return p;
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};
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void *__wrap__malloc_r(void *reent, size_t nbytes) {
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extern void * __real__malloc_r(size_t nbytes);
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void *p = __real__malloc_r(nbytes); // Solely for debug breakpoint...
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return p;
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};
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// ================================================================================================
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// Implement FreeRTOS's memory API using newlib-provided malloc family.
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// ================================================================================================
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void *pvPortMalloc( size_t xSize ) PRIVILEGED_FUNCTION {
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void *p = malloc(xSize);
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return p;
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}
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void vPortFree( void *pv ) PRIVILEGED_FUNCTION {
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free(pv);
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};
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size_t xPortGetFreeHeapSize( void ) PRIVILEGED_FUNCTION {
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struct mallinfo mi = mallinfo();
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return mi.fordblks + heapBytesRemaining;
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}
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// GetMinimumEverFree is not available in newlib's malloc implementation.
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// So, no implementation provided: size_t xPortGetMinimumEverFreeHeapSize( void ) PRIVILEGED_FUNCTION;
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//! No implementation needed, but stub provided in case application already calls vPortInitialiseBlocks
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void vPortInitialiseBlocks( void ) PRIVILEGED_FUNCTION {};

‎src/heap.c

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#include "../portable/MemMang/heap_4.c"
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#elif (configMEMMANG_HEAP_NB == 5)
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#include "../portable/MemMang/heap_5.c"
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#elif (configMEMMANG_HEAP_NB == -1)
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#include "../portable/MemMang/heap_newlib.c"
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#else
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#error "Wrong Memory allocation implementations defined"
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#endif

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