heap_4 - infinite loop in prvInsertBlockIntoFreeList() from vPortFree() or pvPortMalloc()

Kernel
1

gabor90 wrote on Wednesday, July 08, 2015:

Hi!

I have some problems using this code:
In the prvInsertBlockIntoFreeList() 's

for( pxIterator = &xStart; pxIterator->pxNextFreeBlock < pxBlockToInsert; pxIterator = pxIterator->pxNextFreeBlock )
{
/* Nothing to do here, just iterate to the right position. */
}

this turn into infinite loop,

and

pvPortMalloc() 's
while( ( pxBlock->xBlockSize < xWantedSize ) && ( pxBlock->pxNextFreeBlock != NULL ) )
{
pxPreviousBlock = pxBlock;
pxBlock = pxBlock->pxNextFreeBlock;
}

It has the same issue.

For example, in prvInsertBlockIntoFreeList():
pxIterator 's value ==> 0x200157d8 <xHeap+84464> xBlockLink *
pxIterator->pxNextFreeBlock ==> 0x200157d8 <xHeap+84464> struct A_BLOCK_LINK *

I found some similar topic in this forum, but they cannot help me:

  • is declaration corrupt? Why and what data could be corrupt?
  • overwrited data? how can i find that?

The classes, which i use, call pvPortMalloc() and vPortFree() functions are working fine.

I tried to increase the totalHeap, but it didn’t help me.

I use FreeRTOS V7.3.0
and heap_4.c.

Thank you for all help,
Best regards
Gábor

2

rtel wrote on Wednesday, July 08, 2015:

Things to check include:

  1. That the same block is not being freed twice. Recent versions of FreeRTOS will trigger a configASSERT() if the same block is freed twice, but I’m not sure if V7.30 (which is a bit old now) has this assert check or not. Do you have configASSERT() defined?

  2. Nothing is corrupting the memory immediately in front block being freed, which contains some meta data.

Regards.