Re: [luabind] Destructors

[Tom S. <to...@si...>]

> I suppose we could nil all the members of the table
> to ensure that the objects can be collected on the first cycle.
>
> This seems like it would add unnecessary overhead though, it seems more
like
> an issue with lua's GC than luabind.

    I agree...  i'll bring this up on the lua list, but use the double gc()
call in the meantime.

> This is a good idea, a __destroy or __finalize function should probably be
> added.

    __finalize sounds better to me.

    Tom


----- Original Message ----- 
From: "Daniel Wallin" <dal...@st...>
To: <lua...@li...>
Sent: Friday, April 25, 2003 5:16 AM
Subject: Re: [luabind] Destructors


> At 21:15 2003-04-23, you wrote:
>
> >     I'm running into an issue with destruction of luabind classes.  If i
> >have the code...
> >
> >         class 'my_class1'
> >
> >         function my_class1:__init()
> >             self.cpp_object = create_cpp_object()
> >         end
> >
> >         class 'my_class2'
> >
> >         function my_class2:__init()
> >             self.my_class1 = my_class1()
> >         end
> >
> >         function my_class2:clean()
> >             self.my_class1 = nil
> >             collectgarbage()
> >         end
> >
> >         _the_class2 = my_class2()
> >         _the_class2:clean()
> >
> >
> >     What happens is that "my_class1:cpp_object" which was created by a
> >luabind is not destroyed via it's destructor within the
"my_class2:clean()"
> >call.  I assumed that nil'ing the parent class would automatically nil
all
> >members of the class since there is no way to define a destructor for a
> >luabind class.  Is this a bug in the class system or do i need to create
my
> >own destruction call like...
>
> When the my_class2 instance is collected, it releases the references to
> it's table. However, lua's GC might not collect the objects that are
referenced
> in the table in the first cycle. You might need to call collectgarbage()
> more than
> one time to collect all objects. I suppose we could nil all the members of
> the table
> to ensure that the objects can be collected on the first cycle.
>
> This seems like it would add unnecessary overhead though, it seems more
like
> an issue with lua's GC than luabind.
>
> >         self.my_class1.destroy()
> >         self.my_class1 = nil
> >
> >     ... which in my opinion is nasty.  Ideally for me i'd like to see
both
> >an optional destructor member like "__destroy" called on destruction and
> >forced automatic nil'ing of all members after the "__destroy".
>
> This is a good idea, a __destroy or __finalize function should probably be
> added.
>
>
> Daniel Wallin, dal...@st...
>
>
>
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