[Devel] Re: Cache manager FREE problem [was: Anyone there?]

[Tom Kacvinsky]

I am using the current cvs code (post 2.0.2) .  I was wondering what the 
differences
were. :)

Tom

On Fri, 6 Apr 2001, Mike Owens wrote:

> Your code is not the same as mine in either module. I have freetype 2.0.1. Is 
> this the latest version?
>
> >>> Tom Kacvinsky <address@hidden> 04/06 4:23 PM >>>
> Hi!
>
> I am confused here...
>
> In ftlru.c, we have this:
>
>   FT_EXPORT_DEF( void )  FT_Lru_Done( FT_Lru  lru )
>   {
>     FT_Memory  memory;
>
>
>     if ( !lru )
>       return;
>
>     memory = lru->memory;
>
>     FT_Lru_Reset( lru );
>
>     FREE( lru->nodes );
>     FREE( lru );
>   }
>
> So the lru->nodes are freed before lru is freed.
>
> In ftcmanag.c, we have this:
>
>   FT_EXPORT_DEF( void )  FTC_Manager_Done( FTC_Manager  manager )
>   {
>     FT_Memory  memory;
>     FT_UInt    index;
>
>
>     if ( !manager || !manager->library )
>       return;
>
>     memory = manager->library->memory;
>
>     /* now discard all caches */
>     for (index = 0; index < FTC_MAX_CACHES; index++ )
>     {
>       FTC_Cache  cache = manager->caches[index];
>
>
>       if ( cache )
>       {
>         cache->clazz->done_cache( cache );
>         FREE( cache );
>         manager->caches[index] = 0;
>       }
>     }
>
>     /* discard faces and sizes */
>     FT_Lru_Done( manager->faces_lru );
>     manager->faces_lru = 0;
>
>     FT_Lru_Done( manager->sizes_lru );
>     manager->sizes_lru = 0;
>
>     FREE( manager );
>   }
>
> So I don't see how lru->nodes is freed twice, or how lru->nodes is not freed
> before lru is freed.  So I would need to know which FREE is causing the memory
> access violation.
>
> I am CC'ing my response to the list, where this discussion is best kept.  I
> mean, the more eyes on this, the better. :)
>
> Tom
>
> On Fri, 6 Apr 2001, Mike Owens wrote:
>
> > Thanks for your response. I just wasn't sure if my message was getting out
> > there.
> >
> > If this helps, I've traced into ftlru.c where FT_Lru_Done() gets called from
> > FTC_Manager_Done() (ftcmanage.c). FT_Lru_Done calls FT_Lru_Reset which seems
> > to be rearranging the nodes. However immediately following FT_Lru_Done is
> > FREE(lru) which frees the lru memory but not the lru->nodes.
> >
> > Thanks again for your response.
> >
> > > We are getting the messages.  As I have said in the past, David Turner 
> > > (the
> > > coder responsible for the cache manager) is a busy man, but he will 
> > > eventually
> > > will get around to answering your email. :)
> > >
> > > But in meantime, it sounds like you have stumbled across a dangling 
> > > pointer
> > > problem.  The structure is getting freed before all of its consituent 
> > > members
> > > are freed.
> > >
> > > I will try to cook up a patch, but it will most likely take me some time
> > > because I am not familiar with the cache manage code.  I spend most of my 
> > > time
> > > in the CFF, CID and Type 1 drivers.
> >
>
>