Re: How far should one go preventing potential memory leaks?

[Thomas Jericke <tjericke@...>]

On 05/10/2016 08:41 AM, Marc Balmer wrote:
> This prevents a memory leak if lua_pushstring() raises an error, but I 
> will end
> up with a number of rather small allocations that are only used for a 
> short
> period of time.
If they buffers are really that small, I would just use the stack.

char s[32];
snprintf(s, sizeof(s), "bumblebee");
lua_pushstring(L, s);

After all, this doesn't use more stack space then having 4 local doubles 
in your C function.

> Wouldn't it be nice to have a explicit call in the Lua API to
> free a userdata value immediately, e.g.
>
> char *s = lua_newuserdata(L, 32);
> snprintf(s, 32, "bumblebee");
> lua_pushstring(L, s);
>
> lua_freeuserdata(s)
>
> Or do you think the garbage colletor overhead can be neglected?

I think such a function would only reduce memory overhead and not CPU 
overhead.
lua_freeuserdata(s) would have to check whether there is still a valid 
reverence to that userdata.
--
Thomas