Is there an alternative to debug.sethook()?
I'm trying to add a little extra safety to a sandbox I've created. On top of doing all the ENV changes, I want to limit CPU and memory usage.
This is some quick and simple Lua code that (mostly) accomplishes that:
01 | local stepLimit = 50 --Maximum instructions |
02 | local memLimit = 1000 --Max memory in KB |
03 | local count = 0 --Counter for the steps |
04 |
05 |
06 | local function checkMem() |
07 | if collectgarbage("count")>memLimit then --If too much mem usage |
08 | error("uses too much memory") |
09 | end |
10 | end |
11 |
12 | local function step() |
13 | checkMem() --check mem usage |
14 | count = count+1 |
15 | if count>stepLimit then -- if too much CPU usage |
However, Roblox uses a modified version of Lua 5.1.4, which lacks debug.sethook() as a function.
Running this code simply gives:
attempt to call field 'sethook' (a nil value)
(Commenting out the debug.sethook() line makes the code run, everything else is fine)
So if I cannot use this, how else can I manage memory and CPU?
1 answer
Thank you to "howmanysmall" on the Lua Learning Discord
Well, rather than be able to set a hook, I can create a thread alongside it.
1 | spawn(function() |
2 | while wait() do |
3 | local MemUsage = collectgarbage("count")/1000 --(/1000 makes it MB which I prefer) |
4 | --print("memUsage:", MemUsage, "(in MB)") |
5 | if (MemUsage) > MemLimit then |
6 | error('{Code abortion}-"Using too much memory"') |
7 | end |
8 | end |
9 | end) |
Not the best (or even close to it), but it does help.
Still no clue how to handle overusing CPU!