AI Lag Bandaid

[ondrej008]

About the PR

Sort of resolves #3783

Why / Balance

So the client & server lag less

Media

Requirements

• I have read relevant guidelines/documentation to this PR found on our devwiki.
• I have added media to this PR or it does not require an ingame showcase.
• I can confirm this PR contains either no AI-generated content, or AI-generated content that meets our guidelines.

How to test

test on live

Breaking changes

Changelog

🆑

• fix: A relic from NanoTrasen has uncovered a way to make AI cores less compute intensive.

[ondrej008]

also I do want to claim this for the bug bounty thing that nigel announced, though idc about in-game rewards

[EckoAurum]

I can understand where you're coming from, as you might see a performance increases in testing as you make it's vision single-threaded. But this will cause significantly more lag whenever there's more than single AI doing vision checks.

[ondrej008]

I can understand where you're coming from, as you might see a performance increases in testing as you make it's vision single-threaded. But this will cause significantly more lag whenever there's more than single AI doing vision checks.

it is rare for there to be more than one AI in a single round, you can tell because whenever an AI is in the round lock contentions go up to 100 c/s (check with grafana) currently on live, so any round with lock contentions below 100 c/s has no AIs in it at all
also this should be tested on live before you make a statement like this
the code is not written to take account of multithreading as it spams lock contentions out the ass so much that the performance is worse than it being singlethreaded by 3x, this means that 3 AIs on singlethreaded should be the same as 1 AI on multithreaded mode

[ondrej008]

ideally someone would rewrite the entire AI vision system to actually be multithreaded well but that would be a lot of work and needs a lot of C# multithreading and SS14 multithreading experience

[ondrej008]

oh my god I just read the AI code someone go tell metalgearsloth to never touch multithreading again
a lock inside a for loop... I'll see if I can fix it without making it singlethreaded

[Redrover1760]

Making it singlethreaded is not a fix, its a surrender of our multithreaded rights to the evils of the lag demons.

On that note good luck

[ondrej008]

test on release multithreaded:
Zenith ADM client fps ~400, server fps 410-440
Zenith ADC client fps ~300, server fps 400-415

test on release singlethreaded:
Zenith ADM client fps ~400, server fps 410-440
Zenith ADC client fps ~350, server fps 400-420

so on my localhost I can't see much of a difference server-side, but it does improve client fps, idk

test on release multithreaded with changes:
Zenith ADM client fps ~400, server fps 410-440
Zenith ADC client fps ~240, server fps 360-410

apparently Microsoft's ConcurrentDictionary which is supposedly magically lock-free is not lock-free after all, had about 50% or 100% more lock contentions
will continue the search for a better datastructure or maybe just give up

[ondrej008]

nvm I found something good, 400-420 server fps and 350 client fps w/ multihreading