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Heap allocate size ...

Posted by debugasm on March 29, 2016

Hi,

in my application I use a heap memory with code of "heap4". I have the need to use the "realloc" function to provide a already allocated memory area. I have write a wrapper to this function on "heap4" but I realized now that I do not know the size of the old allocation to copy the old content to the new memory area.

There is a function "mallocusablesize" that returns this value but how implement this routine in "heap_4" ?

You can know the size of a memory block allocated by vPortMalloc ?

Thanks very much.

debugasm


Heap allocate size ...

Posted by rtel on March 29, 2016

The size of every block is stored in a BlockLink_t structure, in the allocated block itself. See the implementation of vPortFree() for an example of how it is accessed.


Heap allocate size ...

Posted by debugasm on March 29, 2016

I understand, thank you so much.

debugasm


Heap allocate size ...

Posted by debugasm on March 30, 2016

To be precise:

~~~~ // The block is being returned to the heap - it is no longer allocated. block_size = (pxLink->xBlockSize & ~xBlockAllocatedBit) - xHeapStructSize; ~~~~

Obtain block size allocate by "pvPortMalloc" rounded to "BYTE_ALIGNMENT"

debugasm


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