Re: Userdata and GC

[Ty Matthews <tmatthews3@...>]

Thanks for the help.  I think I was going along those lines, but I just wasn't sure.  I'm planning on using Userdata to tuck away a pointer for some memory that I need to control, but pass it back and forth between C and Lua.  The script is the "owner" of the pointer, since it is the only piece that needs/uses it and can tell me when it is no longer necessary.  

With that type of mechanism, how do I find out when the object is really no longer used by Lua?  I assume I need to define my own GC function and tell Lua about it.  The docs say you can define a GC metamethod for your Userdata, but I don't see any info on how to go about actually setting one up.  Are there any C API sample programs or code snippets out there that demonstrate a Userdata GC function?

Thanks again-
   
    Ty


>You should never free memory which Lua has allocated. You should always 
>free memory which you have allocated. (Lua never "takes" or "gives" 
>ownership of memory. If you have a call to malloc() or free, you need a 
>matching call to free() or delete. Or whatever you use to allocate 
>resources.) It is really that simple.

>If you want to handle your own memory, use the userdata only to hold a 
>pointer to an object you have allocated.

>Hope this helps.

>R.