Re: GC

[Asko Kauppi <askok@...>]

I've recently done a C++/Lua binding, which is really simple,  
efficient and I would say elegant.

It is based on a customized C++ 'new' operator, so pushing an object  
is done as:

	myobj *m= new(L) myobj();

	or if the C side does not need that object, just:

	new(L) myobj();

Of course any constructor will be valid (here without parameters).

The object's memory is allocated from Lua stack, and __gc is bound so  
that the C++ delete operator gets called automatically.

I've enjoyed using this mechanism for the customer project, and I can  
ask them to release it (with MIT license) if there is interest on the  
list.

-asko


Javier Guerra kirjoitti 5.5.2009 kello 18:38:

> On Tue, May 5, 2009 at 10:27 AM, Gergely BOROMISSZA
> <Gergely.BOROMISSZA@navngo.com> wrote:
> > I've already read the manual but my __gc function was only called  
> > when I quit the program or when I call collectgarbage manually. So  
> > there was a plenty waste of memory which was not freed.
>
> what happened was probably that the GC didn't see any need to collect.
>
> Lua only keeps track of the memory used inside Lua.  if your userdata
> holds only a pointer, or a small structure with references to bigger
> objects, that would be the only size that Lua knows about.
>
> to get better results either put most of your object's data inside the
> userdata, or add some close() method that releases any resource
> external to Lua.
>
> --
> Javier