[fpc-devel]Improvements for heaptrc.pp

Mattias Gaertner nc-gaertnma at netcologne.de
Fri Oct 11 12:41:10 CEST 2002

On Wed, 4 Sep 2002 14:46:37 GMT
Peter Vreman <peter at freepascal.org> wrote:

> > > What can be a speed improvement is to have a value that determines how > > heap is
> checked. So you can do it only once for each 10 allocations.
> > 
> > Good idea.
> > This Frequency should be a public variable, so it can be changed at any time.
> > I use the CheckHeap procedure to binary search heap destructions in programs with
> millions
> of allocations. You can imagine, that each heap check costs a lot of time. But with
> CheckHeap, binary search and of course the speedy fpc, you can track down bugs in minutes,
> that would cost in other languages days to find.
> > 
> > 
> > > Also checkpointer can shall be extended with a possibility to check if the pointer is
> not
> > > in one of the freed memory blocks. Together with the keep_released flag it can then be
> > > used to find dangling pointers.
> > 
> > :)
> > 
> > Who will do it?
> I'll do it, so you can continue your good work on Lazarus :)

heaptrc must be improved.

I have a problem with Lazarus. 
I tried lazarus with cmem and it crashed. heaptrc did not found the error, nor my memcheck, an slightly improved heaptrc, which already contains the changes I suggested. Using heaptrc with keep_released needs several minutes and then thousands of linked list error appeared, so it was useless.
The reason was an object, that was freed twice. I fixed that, so Lazarus now runs with cmem. But I'm sure there is another mem corruption. 
I tried memprof, but it simply crashed.

So, what I need is a mem checker, that can detect double freed blocks AND that does not need keep_released, because I dont have the time and mem to run AND that reacts with a useable output.

Does someone know a solution? 


More information about the fpc-devel mailing list