Re: Wx::Perl seems to be leaking memory

Hi Mark,

Thanks for this.  So the short answer was that I had indeed made a 
fundamental error.  I should update PM.

Maybe I knew all this once upon a time, but I had definitely forgotten 
it long since!!  It explains why I had leaks all over the place.  Some 
of which must have been quite big because of embedded scrolling photos 
and other stuff.

Can I just clarify what is meant by "toplevel".  I guess it means 
anything that groups controls that you would normally expect to disapear 
because of going out of scope: any Dialog, Panel or Frame with children 
or indeed a tree of descendants.  Or does it just mean the application 
main frame?

And if a whole tree goes out of scope simultaneously, eg controls in 
sizers on panels within panels in a dialog, is it enough to Destroy the 
dialog?

Thanks again,

Regards,

Steve.

On 11/05/15 11:52, Mark Dootson wrote:
> Hi,
>
> See 
> http://docs.wxwidgets.org/3.0/classwx_window.html#a6bf0c5be864544d9ce0560087667b7fc
>
> details for wxWindow::Destroy.
>
> As you have determined, top level windows you create need to be 
> destroyed with $win->Destroy;
>
> The C++ structure for a Wx::Frame contains a reference to the 
> associated Perl SV. So that SV won't go away until the C++ structure 
> is deleted - which will never happen until your event loop is running.
>
> Hope this helps.
>
> Mark
>
>
> On 11/05/2015 14:32, Steve Cookson wrote:
>> Hi Guys,
>>
>> I started to talk about this on Perl Monks, you may have seen it here:
>>
>> http://www.perlmonks.org/?node_id=1125580
>>
>> An anonymous monk posted some code that showed just about every call 
>> to Wx leaking a scalar or two.  I've played about with the posted 
>> code and there is a copy attached to this email.
>>
>> The main part of the code, here:
>>
>>         $count1 =  Devel::Leak::NoteSV($handle);
>>         for(1..100){
>>             my $f=Wx::Frame->new( undef ,-1,"goner" );
>>             my $p=Wx::Panel->new (undef ,-1 );
>>             #my $b=Wx::Button->new ( $f ,-1 );
>>             #my $t=Wx::TextCtrl->new($f, -1, "");
>>             #$t->Destroy;
>>             #$b->Destroy;
>>             #$i->Destroy;
>>             $p->Destroy;
>>             $f->Destroy;
>>         }
>>
>>         $count2 =  Devel::Leak::CheckSV($handle);
>>
>> seems to show that if you do not ->Destroy a Wx object, it will not 
>> go out of scope naturally and even if you do destroy a Wx::Frame 
>> object, it will not go out of scope.  The monk also tried Weaken and 
>> undef, with the same results.
>>
>> Please have a look at this and make sure that I have not (or the 
>> Anonymous Monk has not), made some fundamental error.
>>
>> I have checked it both in 2.8.11 and 3.0.2 with the same results.
>>
>> I look forward to hearing your feedback,
>>
>> Regards
>>
>> Steve.
>
>