Re: Stack overflow

[Sean Middleditch <elanthis@...>]

On Thu, 2002-05-02 at 16:27, Jens Hassler wrote:
> Hi there,
> 
> I think this is a typical beginner problem, so I hope someone can give me  
> an answer :)
> 
> In my C(++) code of my game project I call a hook function defined in the  
> Lua code with a handle to a game object (passed via a "tolua" function)  
> each time when it is updated:
> 
> ------------------------------------------------------------------------
> int do_hook_object_update(Object *o)
> {
>   char func[50];
>   int retcode = 0;
> 
>   sprintf(func, "hook_object_update", n);

What is with this line?  What is the variable n there? Also, if you're
calling 60 times a second, you'd be a lot better off not bothering with
the buffer/sprintf at all, and instead just doing

lua.getglobal ("hook_object_update");

That'll save on the data shuffling, which on modern processes, tends to
be what bites you in the arse the most, speed wise.

>   lua.getglobal(func);
>   tolua_pushusertype(lua.get_state(),(void*)o,tolua_tag(lua.get_state(),"Object"));
>   lua.call(1, 1);
>   if (lua.isnumber(1)) ret = (int)lua.tonumber(1);
> 
>   return ret;
> }
> ------------------------------------------------------------------------
> 
> 
> I do this with other events, too (when object is dead, when it is hit, and  
> so on), but the code above is called 60 times a second - and this is  
> causing a stack overflow after a few seconds.
> 
> The lua functions are encapsulated inside a little C++ class I found  
> somewhere, so don't mind :)
> 
> Am I doing something really nasty wrong?
> 
> 
> Thx a lot,
> Jens