memory leak detection patch

[Mike McCormack]

Hi,

This patch is written for MSI, but could be adapted to other code.  It 
keeps a linked list of allocated memory and removes free'd memory from 
the list.

It requires that you change all the HeapAlloc's or mallocs in a dll to 
msi_alloc (for example), but can detect unfree'd memory and invalid free's.

I have discovered quite a few problems in my own code with this patch, 
so hopefully somebody else will find it useful too.

Mike

[Andreas Mohr]

Hi,

On Thu, Sep 22, 2005 at 12:08:20AM +0900, Mike McCormack wrote:
> Hi,
>
> This patch is written for MSI, but could be adapted to other code.  It 
> keeps a linked list of allocated memory and removes free'd memory from 
> the list.
>
> It requires that you change all the HeapAlloc's or mallocs in a dll to 
> msi_alloc (for example), but can detect unfree'd memory and invalid free's.
>
> I have discovered quite a few problems in my own code with this patch, 
> so hopefully somebody else will find it useful too.

First, thanks for fixing so many leaks!

I think that we should concentrate on making valgrind the default leak
detection method in Wine, however.

Reasons:
- it catches many, many leaks *without any reprogramming effort*
- it catches many, many other problems
- it has other tools which are very useful, too (cache profiling, ...)
- it's so much better than any other "clever hack" that people come up with
  in 2 hours

Thus IMHO valgrind should work perfectly with Wine, and it should be the
first thing that pops up when people want to do things like this: IOW
it should be documented rather prominently which are some useful ways of
using it in combination with Wine.

OTOH we might want to put a safety net in place in case valgrind somehow
becomes impossible to use in combination with Wine, so maybe we should
investigate a second leak tracer, too.

Or am I completely mistaken here?

Andreas

[Mike McCormack]

Andreas Mohr wrote:
> I think that we should concentrate on making valgrind the default leak
> detection method in Wine, however.
>
> Reasons:
> - it catches many, many leaks *without any reprogramming effort*
> - it catches many, many other problems
> - it has other tools which are very useful, too (cache profiling, ...)
> - it's so much better than any other "clever hack" that people come up with
>   in 2 hours

Valgrind is great, and I've used it before, but it's a little heavy duty 
for what I want at the moment.

The main disadvantages are:

- it slows down Wine and programs running Wine. (Office 2003 install 
already takes a minute or so)
- it doesn't differenciate between Wine leaking memory and a program 
running in Wine leaking memory
- it requires a patched version of Wine to run
- it isn't built into Wine (ie. I could ship this patch with minimal 
overhead, and have my users point out memory leaks)
- it has issues following forks, and being run from scripts

The patch is not meant to replace valgrind, just to provide another way 
of finding problems in Wine code.

Mike

memory leak detection patch (usable for

[Detlef Riekenberg]

Hi Mike
> This patch is written for MSI, but could be adapted to other code.  It 
> keeps a linked list of allocated memory and removes free'd memory from 
> the list.

Nice Hint.
I will reuse that, while working on the Printing subsystem.
> so hopefully somebody else will find it useful too.

should we implement this for all with something like:

WINEHEAP_DEFINES(prefix)
wineheap_alloc
wineheap_realloc
.
.
.
wineheap_dump_allocated_memory




-- 
By By ...
      ... Detlef

memory leak detection patch (usable for

[Oliver Stieber]

--- Detlef Riekenberg <wine.dev(a)web.de> wrote:
> Hi Mike
> > This patch is written for MSI, but could be adapted to other code.  It 
> > keeps a linked list of allocated memory and removes free'd memory from 
> > the list.
>
> Nice Hint.
> I will reuse that, while working on the Printing subsystem.
> > so hopefully somebody else will find it useful too.
>
> should we implement this for all with something like:
>
> WINEHEAP_DEFINES(prefix)
> wineheap_alloc
> wineheap_realloc
> .
> .
> .
> wineheap_dump_allocated_memory

There's a possibility that WINEs heap management is going to be improved at some point by keeping
all small allocations together and caching them to improve performance and reduce fragmentation.
I'm not sure how much this is vaporware but it could be fairy well intergrated with some kind of
memory tracking system.

Oliver
> -- 
> By By ...
>       ... Detlef

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