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Getting memory usage of a single widget
Posted: 23 Sep 2021, 17:00
by Beherith
While the profiler is nice to get the ram usage delta, I have found no way of accessing what local variables a widget has inside its own 'scope', to calculate how much ram its using in mostly table data.
Example widget:
Code: Select all
function widget:GetInfo()
return {
name = "*GETMEMORYUSAGE",
desc = "Tries to print ram usage",
author = "Beherith",
date = "2021 Sept",
license = "GNU GPL, v2 or later",
layer = 0,
enabled = true -- loaded by default?
}
end
local BigTable = {1,2,3,4}
local IWantThisOne = true
function widget:Initialize()
local IDontWantThisOne = true
end
function widget:GameFrame()
BigTable[ #BigTable + 1 ] = #BigTable
local ThisVariableActualllyGetsFoundByGetLocal = true
while true do
local i = 1
local n, v = debug.getlocal(1, i)
if not n then break end
Spring.Echo(n)
i = i+1
end
end
In this case, I dont know how to get the variable BigTable, as it does not appear in the getlocal list. How should I iterate through all the variables that have been declared in the widget's scope?
EDIT: I have tried sifting recursively through all the variables returned by debug.getlocal at both stack levels 1 and 2, but BigTable is never in it
Re: Getting memory usage of a single widget
Posted: 23 Sep 2021, 18:52
by Silentwings
Can't remember exactly how the lua allocation (esp strings) / localization / garbage collection works, but my fast decaying memory from (re)writing the profilers is that this is impossible and not even well defined - even if it were a widget that avoided allocating memory outside of its "own" pointer tree stemming from its location in the handlers WG table (that's where the locals will be found fwiw).
Re: Getting memory usage of a single widget
Posted: 24 Sep 2021, 09:07
by Beherith
Ok, for the record, i did not find any locals in the wg table, only the ones explicitly exported to it.
Re: Getting memory usage of a single widget
Posted: 24 Sep 2021, 10:04
by Silentwings
You'll need to look in the handlers tables (which iirc live inside the "real" WG - you don't want the wrapped stuff the handler exposes to non-handler widgets). The widget file is pcalled by the handler
https://github.com/beyond-all-reason/Be ... s.lua#L435 as part of the widget loading, with setfenv as a table that in the eyes of the handler eventually becomes "the" widget, along with lots of other stuff (callins, etc) that is added later. The eventual insertion seems to be here
https://github.com/beyond-all-reason/Be ... s.lua#L775 so probably you need to look in widgetHandler.widgets and then the array index of the widget in question (which iirc is its precedence in reverse callin execution order, coming from the "layer" parameter - probably have to search the array to find it because only the handler knows this and it can change dynamically). But my memory is pretty old, 20% chance I've just written nonsense...
Also someone added a variable that isn't in camelCase
https://github.com/beyond-all-reason/Be ... ts.lua#L58 and as punishment they should be made to commit a loop that prints 100 lines of "I must remember to use camelCase".
Re: Getting memory usage of a single widget
Posted: 24 Sep 2021, 13:32
by Beherith
Ok, ill keep trying to dig deeper, as trying to recursively traverse all tables at a depth of 4 becomes already too large :)
Also, dont blame camelcase, blame it on someone who thought turning all map/modoptions table keys to lowercase!
