[Qt-interest] Static destructors errors

[marc at mferland.net]

Quoting "Colin S. Miller" <no-spam-thank-you at csmiller.demon.co.uk>:

> marc at mferland.net wrote:
>
>> Hi all,
>>
>> I've posted about this problem a while ago but didn't have the time to
>> correctly answer the questions/requests that was asked to me (sorry
>> about that!). So here I go again.
>>
>> I'm currently working on a large project involving Qt 4.5.2 and we have
>> a really strange problem when closing the application. More precisely,
>> the application crashes 50% of the time in different static destructors.
>> See the following stack traces for more information:
>>
> <snip!>
>
> Marc,
> Do either of the destructors use data in the other class?
>
> Colin S. Miller

Hi Colin,

I don't think so... These are internally (private) used containers so  
I don't really how they are used. Your thinking that maybe one is  
destroyed before the other?

On my side, I've checked if our problematic static containers where  
indeed empty _before_ closing the application and it doesn't really  
change anything whether they are empty or not.

One detail I forgot to mention in my last post is that in the  
timerDestructor case, the problem is caused by a corrupted iterator  
inside a for-loop. I've traced the loop in a debugger and for some  
reason, calling a delete changes the value of the iterator... malloc  
bug? (would be really surprising IMHO).

The for loop looks like this (from qabstracteventdispatcher.cpp:70):
static void timerIdsDestructorFunction()
{
     // start at one, the first bucket is pre-allocated
     for (int i = 1; i < NumberOfBuckets; ++i)
         delete [] static_cast<int *>(timerIds[i]);
}

Regards,

Marc