[Rd] calloc() vs. R_Calloc()

[Simon Urbanek]

Adrian,

there are many more allocations in your code - for example, you're using resize() from utils.c which uses malloc/free so it will break since it's using the wrong allocator. You may need to replace *all* allocations in your project, not just some.

Cheers,
Simon


> On 8/04/2022, at 6:45 AM, Adrian Dușa <dusa.adrian using gmail.com> wrote:
> 
> Dear Rui,
> 
> Thank you so much for the response, that's a very good observation but I've
> just tested and results in the same errors, unfortunately.
> 
> I have now changed all malloc()s to R_Calloc(), in the latest commit:
> https://github.com/dusadrian/QCAtest/blob/main/src/CCubes.c
> 
> And yet:
> https://builder.r-hub.io/status/QCA_3.16.tar.gz-e652c850de7e51c4cc1311fafe44f986
> 
> There must be something obvious I am missing, but my C knowledge is limited
> and already stretched out...
> 
> Best wishes,
> Adrian
> 
> On Thu, 7 Apr 2022 at 18:49, Rui Barradas <ruipbarradas using sapo.pt> wrote:
> 
>> Hello,
>> 
>> Tomas is right, there are many memory operations allocating with malloc
>> and freeing with R_Free:
>> 
>> line: variables - operation
>> 
>>  55: p_pichart - malloc
>> 336: p_pichart - R_Free
>> 
>> 236: copy_implicants - malloc
>> 260: copy_implicants - R_Free
>> 
>> 240: p_tempic - malloc
>> 262: p_tempic - R_Free
>> 
>> 
>> And there are more cases like these. For what I've seen, the frequent
>> (unique?) case is malloc/R_Free.
>> 
>> Hope this helps,
>> 
>> Rui Barradas
>> 
>> Às 09:59 de 07/04/2022, Tomas Kalibera escreveu:
>>> 
>>> On 4/7/22 10:32, Adrian Dușa wrote:
>>>> On Thu, 7 Apr 2022 at 10:32, Tomas Kalibera <tomas.kalibera using gmail.com>
>>>> wrote:
>>>> 
>>>> 
>>>>     [...]
>>>> 
>>>>     And what are the errors you run into? On which platforms, under
>> what
>>>>     circumstances, etc? It would be much easier to give advice knowing
>>>>     that.
>>>> 
>>>>     In principle, one issue you may run into when switching allocators
>> is
>>>>     that you accidentally end up freeing by a different allocator from
>>>>     the
>>>>     one used to allocate it. It is common on Windows but can in
>> principle
>>>>     happen elsewhere as well.
>>>> 
>>>>     Also by a slightly different heap layout or different allocator
>>>>     implementation you may wake up bugs in the program not seen
>>>>     previously
>>>>     (use after free, invalid memory accesses, etc)
>>>> 
>>>> 
>>>> That is something I do not know yet, since the only information the
>>>> server gives is this:
>>>> 
>> https://builder.r-hub.io/status/original/QCA_3.16.tar.gz-a03b4462b41df37c6284be1d5519e8b3
>>>> 
>>>> I'll probably end up debugging the C code, but since the only
>>>> difference is using Free() vs free() on exactly the same objects, I
>>>> suspected a mis-usage of the R commands.
>>>> 
>>>> The same setup passes with no problems on my local MacOS, but the
>>>> errors still seem to occur on the Windows setup from r-hub.
>>> 
>>> This is very likely because you are freeing memory allocated by calloc()
>>> (or something else but not R_Calloc() in your program) using R_Free() or
>>> memory allocated using R_Calloc() by using free() in your program.
>>> I would recommend checking the source code manually for that.
>>> 
>>> It is not surprising that the problem doesn't appear on other platforms
>>> where the allocators happen to be the same.
>>> 
>>> Best
>>> Tomas
>>> 
>>> 
>>>> 
>>>> Best wishes,
>>>> Adrian
>>>      [[alternative HTML version deleted]]
>>> 
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