Authors CurseForge

I have noticed while developing on my addon that sometimes, when messing with functions which are continuously called from "OnUpdate" frame scripts, the memory usage for my addon start to rise aggressively (like +2kb per sec). I am quiet sure that local variables in the called functions are the guilty ones for this rise in memory usage.

--this stuff is continuously updated
someFrame:SetScript("OnUpdate", 
	function()
		someFunction()
	end)
	
function someFunction()
	local var1
	local var2
	local var3
	...
end

I guess new memory for those local variables are allocated all the time, and then the garbage collector kicks in once in a while to clean up and then the rise of memory usage starts over again.

If my assumption is correct, is it then better to refrain from using local variables in such functions and use global ones instead? OR is it best to use local variables because they use less CPU to access compared to global variables?
Access to global variables in for example C programming is CPU expensive, but then again C is stack-based and Lua is register-based-VM...

ok thank you didn't think about that as I just tend to put all my functions and stuff into tables and use local variables inside my functions all the time.
Guess I have some optimization to be gained then :)

Thank you again for your answers, just thought I would add a bit more to help anyone else who might read this thread (and maybe to get someone to clarify it a bit).

This is more 'World of Warcraft Lua' specific though.
I have experienced huge memory leaks because of code like this:

Frame:Hide()

which I was repeatedly calling even when the Frame was already hidden.

My solution to this is to instead write:

if Frame:IsVisible() then
Frame:Hide()
end

sorry for the necro, but it does pertain to the topic

would a string be considered a table?

function someFunction( str )
	local var1 = str:sub(1,5) ;
	local var2 = str:sub(6,9) ;
	...
end

would i be leaking memory via var1 and var2? am i supposed to clean that up before leaving scope??

function someFunction( str )
	local var1 = str:sub(1,5) ;
	local var2 = str:sub(6,9) ;
	...
        -- cleanup
        var1 = nil ;
        var2 = nil ;
end

??