Lag spikes with Internal ScriptContext

[limber finch]

In my developer console whilst playing, the Internal ScriptContext starts at 140, then progressively builds to 5000, then it causes a huge lag spike and resets to 140. Any reason for this, or any fix??

[south marsh]

theres a script that probably causes that

[limber finch]

inside of a script, what can cause that number to go up?

I dont understand what internal script context even is

[cloud estuary]

screenshot where

[split sparrow]

i agree with ve

[limber finch]

what am i screenshotting????

Theres no error code, and i dont know where in the code this is being caused

I dont know what internal scriptcontext is

and its spiking in the dev console

[cloud estuary]

screenshot that

[limber finch]

okay 1 sec

lemme play so i can get it to spike

rn its kind of normal ish

its only doing 1000 spikes

but when i play the game through roblox and get past wave 10 it starts to do 5000 spikes, lag and reset

[cloud estuary]

memory usage?

[limber finch]

i lost so it reset, im moving into the game through roblox

i think memory was above 2500

let me get to wave 10 when it starts spiking, then ill send across all info thats spiking

[cloud estuary]

i meant is this your memory usage, looks like it

[limber finch]

yes

its under the first tab

which is the memory tab

this section

[cloud estuary]

i take it the 1500 is this internal scriptcontext?

[limber finch]

i think so yes

rn on wave 5

1800 spike

goes back down to 80

back up to 2000

[cloud estuary]

it looks like garbage collection cycles, you have a memory leak until roblox streams out some things

due to low memory situation

[limber finch]

this is the highest ones onthe list

[limber finch]

how does this fix??

it was happening to my playtesters too

rn its peaking at 4000

[cloud estuary]

ya thats what memory leak looks like

[limber finch]

its hella laggy

[cloud estuary]

you probably don't dispose of some instances until low memory situation causes roblox to clear them out

[limber finch]

what instances is that, i have projectiles, but i destroy them after they are used

is there a way to test for things that arnt being disposed?

[cloud estuary]

could be anything

you'll have to search for it

[limber finch]

any pointers on things to look for?

[cloud estuary]

any strong reference to an instance will keep it in memory

[limber finch]

Is it just instances that dont get destroyed or what causes memory leaks?

[cloud estuary]

destroyed instances stay in memory if there is a strong reference to it

[limber finch]

what is a strong reference?

[cloud estuary]

any reference that is not a weak reference

[limber finch]

how do i know which is weak or strong, and what is the difference?

[cloud estuary]

a reference is strong when it isnt weak

[limber finch]

can i have an example of a strong reference compared to a weak reference

[cloud estuary]

local x; x=instance.new()

[limber finch]

is that a strong reference?

[cloud estuary]

references are strong by default

[limber finch]

how do you make a reference weak?

[cloud estuary]

metatable

[limber finch]

okay understanding

so lets say im storing something in memory, if i destroy it, its still in memory, so how do i remove it?

[cloud estuary]

x=nil

or let it go out of scope

[limber finch]

so even after destroying it i have to set it to nil?

[cloud estuary]

most of the time yes

[limber finch]

so hold on

other than towerSpawn, would i need to set the other to nil?

and or, is it good practice to always set it to nil anyway, even if its not needed

[cloud estuary]

depends what it is and where

[limber finch]

okay, so im not good at finding memory leaks as iv just been introduced to in roblox, BUT

[cloud estuary]

lots of different things can cause it

[limber finch]

i think iv found it

and i need some clarification from you if thats okay

[cloud estuary]

common one is not clearing tables of bad data

[limber finch]

nail on the head for what im about to send

local blacklist = {}

[cloud estuary]

idk what that is

[limber finch]

wait

would this be the issue

im adding to the list via renderstepped

[cloud estuary]

if you never remove things from the blacklist then yes this is a huge issue major memory leak

[limber finch]

okay, then that could be the issue

how do i remove things from the table?

[cloud estuary]

it's not even the parts are being destroyed, it's that you are inserting duplicates and repeated copies of everything, every frame

RenderStepped:Connect( table.move(blacklist,1,#blacklist,#blacklist,blacklist:clone()) )

[limber finch]

okay, so, for my game i need this to run everyframe and to add to it as when you are placing towers, it adds to blacklist based on what your hovering over when you are spawning a tower

[cloud estuary]

basically you're inserting a full copy of whatever is in the blacklist into the blacklist again every frame

meaning the size of that thing go crazy

and you never clear it

[limber finch]

thats probably why it scales more at later waves

[cloud estuary]

you probably dont need to run this every frame

[limber finch]

as there are more towers to add and not remove

is there a better way around it, the table.inser for towerSpawn blacklists the tower itself to prevent it from flying at the camera

[cloud estuary]

quickest fix i can see is just reset the table at the start of each frame to rebuild it, but tbh this pattern is pretty bad, but eh you're learning and this is how you learn; you try something, it fails, you learn why, and do better the next time.

[limber finch]

the selectedTower one removes anything that will interfere

[cloud estuary]

other options are something like checking if something is already in the table before adding it

[limber finch]

which is why i ask so many questions, sorry if its daunting

[cloud estuary]

listening for instance destroy to remove it from the table

etc

or use weaktable

etc etc

[cloud estuary]

the only daunting thing here is the time i would need to spend to tutor you and there's plenty of other people here who can do that for you 👍 imo you should be able to learn what you need by just searching weaktables at this point, but 🤷 you can do whatever you want

[limber finch]

i didnt even know that weaktables is a thing

[limber finch]

im probably not going to get tutoring, but just incase i do get to a point where i really cant do anything else, where would i find them?

[cloud estuary]

ya most people don't understand what they are until they need it

you don't need a weaktable here

because you're inserting duplicates. weaktables is for a different problem; if you had dead instances in a table but kept the reference alive

i.e, tbl[any] = instance and you just left it there without removing the entry

or tbl[instance] will keep it alive too.

but again... that's not the issue you're having

[limber finch]

im assuming this had something to do with a solution, are you able to explain this code

iv never used table.move before

nor used it on a connect

[cloud estuary]

for _,v in table.clone(blacklist) do table.insert(blacklist,v) end

[limber finch]

also, not to glaze, but you have been a massive help every time you have came into my threads, even if its annoying that sometimes you leave me at a point that forces me to resolve the situation myself without further help, i can tell it has benefitted me

[limber finch]

im guessing the point is to clone the table and then remove it after iv placed the tower?

[cloud estuary]

wat no i was just describing what your code is doing

you're adding a copy of the entire blacklist table onto the end of the blacklist table, so things like players are in there 1000 times for no reason

after enough time this will eat 100% of memory and if it weren't for failsafes, this would crash roblox and/or the user's device.

[limber finch]

this makes sense, im going to try and move these out of renderstepped

but if there are any i cant move out of renderstepped, how would i go around clearing the table

[cloud estuary]

like if all you did was add blacklist={} to the top of renderstepped before populating it again you wouldn't have a memory leak

because the contents of the table from the previous frame(s) get cleared

table.clear() is another function for this

same same

[limber finch]

i know that, but i removed from there yesterday so i can use the blacklist in other parts of the script

[cloud estuary]

well ya i can't do everything for you. and if i hold your hand the entire way, where are you going to have your own small victories? robbing you of that experience is the most unhelpful thing someone can do; at worst, outright giving you working code and you learn nothing, yet there are those who genuinely believe making you entirely dependent on them to complete scripting tasks is what 'help' is.

so i'm glad you have it in you to solve your own problems, that's scripting 👍

[limber finch]

thanks bro, but i do still want to ask questions as i solve this, because the main thing im struggling with now is that im trying to figure out how to make the blacklist work with your idea

if i move the blacklist creation back into the renderstepped, then how would i use it across the rest of my script

[cloud estuary]

hahahaha yeah now you learn why the pattern you were using never worked in the first place it do be like that

and because you relied on this pattern everywhere, now you have to refactor or do some cheap trick just to make it work

[limber finch]

realistically, does the table.insert for blacklist NEED to be in renderstepped, surely theres a way to do it once, or just do 2 seperate blacklists

[cloud estuary]

this is known as technical debt

[limber finch]

but how do you join tables to make 2 seperate ones

[cloud estuary]

where you need to go back and fix bad decisions you made much earlier in development

[limber finch]

[cloud estuary]

the longer your code gets, the more debt you have, and it is a skill to deal with it well. the only way to do that is by making exactly these mistakes, over and over again.

sometimes you can get a hint

[limber finch]

gotta push through

[cloud estuary]

sometimes someone might be like "oh do it like this, it's better this way, trust me bro" and you either go along with it and it just works out and you never learn why, or you do your own thing, and then you become the person telling other what specific way to do it, because you know why it should be done one way and not the other.

it's a, you actually understand why, instead of 'some guy told me to do it this way so i just kept doing it and it kept working idk why it works'

im sure you've seen a lot of those

[limber finch]

this is the reason i avoid youtube at all costs, and also the reason i originally gave up on coding a year ago

originally i was streaming my coding, and it was fun, i reached a new peak viewers of 30 and was getting a consistent 20

but the problem was, EVERYONE was always "This isnt the most optimal way"

and the chat was always arguing about the ACTUAL way

and it was so so so overstimulating to deal with

i much prefer learning my own way

create my own method

my own optimum method

collaboration has less synergy then indie development

[cloud estuary]

ya this is premature optimization

it's easier to argue microoptimizations than actually build anything

[limber finch]

i can tell lmao

[cloud estuary]

or just to shut your brain off and simply be told how to do everything

there's a lot of those people around

[limber finch]

holy they are annoying, i used to have a friend that was like that

literally wouldnt do anything until they were TOLD to

like a dog

[cloud estuary]

yes, that

'you could do x or you could do y'

'yeah but which one is better and which one should I do?'

😮‍💨

[limber finch]

i think asking which one is better is sometimes okay, but asking which one to do is choice

[cloud estuary]

and half the time, the best decision often changes as needs change, or you end up needing a part mix of both, different situations call for different decisions

or on occasion there's no difference other than preference in how you work with it in other places later down the line... but those people usually don't get that far down the line for it to ever make a difference, so they wouldn't know

anyway, memory leaks like this aren't too common, normally it's keeping dead instances in a table like a table of players and you don't remove the player who left

but now you know to keep an eye out for both, and to not infinitely fill a table without some limits on it

[limber finch]

you require to make your own decisions to progress in scripting

[limber finch]

yes, i know this now 😭

im gonna keep this thread open incase i rerun into another issue whilst fixing this.

But thanks for all the help and the chat too, was refreshing