[1.21.1] F3+2 always increases ServerPlayer count

[JLUsr]

In a 1.21.1 server environment, running only NeoForge 21.1.217 and AllTheLeaks 1.1.6, if an OP-ed player presses F3+2, and thus enables the TPS graph, and then disconnects or dies the server side will always see ServerPlayer (minecraft) increase by one (unless the player dies too quickly after spawning). This happens both in LAN instances and Dedicated servers.

To be honest, I don't really know if this issue is something I am supposed to be putting here, or if it is even actually an issue.

logInterval (set to 1 since atl force_refresh doesn't show the Diff)

[12:39:41] [Server thread/INFO] [AllTheLeaks/]: Listing events...
[12:39:41] [Server thread/INFO] [AllTheLeaks/]: Server Player Clone: 4
[12:39:41] [Server thread/INFO] [AllTheLeaks/]: Server Player Logout: 4
[12:39:41] [Server thread/INFO] [AllTheLeaks/]: Listing memory leaks so far...
[12:39:41] [Server thread/INFO] [AllTheLeaks/]: B: 272MB / C: 272MB / Diff: +0MB
[12:39:41] [Server thread/INFO] [AllTheLeaks/]: Memory Leaks detected: (/atl force_refresh to update)
[12:39:41] [Server thread/INFO] [AllTheLeaks/]: | Player:
[12:39:41] [Server thread/INFO] [AllTheLeaks/]: |- ServerPlayer (minecraft): 8

This does over time see the Diff increase (at an incredibly slow rate)

[12:41:41] [Server thread/INFO] [AllTheLeaks/]: B: 272MB / C: 273MB / Diff: +1MB
...
[12:48:42] [Server thread/INFO] [AllTheLeaks/]: B: 270MB / C: 275MB / Diff: +5MB

Manual atl force_refresh just to be comprehensive

[12:46:59] [Server thread/INFO] [AllTheLeaks/]: Logging events from checking leak
[12:46:59] [Server thread/INFO] [AllTheLeaks/]: Server Player Clone: 4
[12:46:59] [Server thread/INFO] [AllTheLeaks/]: Server Player Logout: 4
[12:46:59] [Server thread/INFO] [minecraft/MinecraftServer]: Listing leaks...
[12:46:59] [Server thread/INFO] [minecraft/MinecraftServer]: Player:
[12:46:59] [Server thread/INFO] [minecraft/MinecraftServer]: - ServerPlayer (minecraft): 8

[pietro-lopes]

Which pack is this?
or if it is a custom pack you can join discord and DM me a export link so I can check which mod is causing that

[JLUsr]

It isn't a pack. Just NeoForge and AllTheLeaks

[pietro-lopes]

that is concerning
will investigate

so i just run a server neoforge, connect to it, die and I will see it increase?

[JLUsr]

Run a server
Connect to it
Op the Player
Hit F3+2 and make sure the TPS graph in the lower right is rendering
Die OR Leave the server
In the server run atl force_refresh OR wait for the logInterval to automatically print the information

[JLUsr]

Spun up a quick test instance in Prism and test server with MCSS and recorded a short clip. I originally discovered this issue using an actual dedicated server and my own MC account but recorded this clip using an offline account (as well as putting the server in offline mode) for privacy. Did this for clarity, I hope it is of some use. This example doesn't show the growing Diff as that would require a fairly lengthy clip whilst waiting for it.

AllTheLeaks.F3+2.mp4

[pietro-lopes]

I tried to reproduce and got nothing :/

[19:08:19] [Server thread/INFO] [AllTheLeaks/]: Logging events from checking leak
[19:08:19] [Server thread/INFO] [AllTheLeaks/]: Server Player Clone: 2
[19:08:19] [Server thread/INFO] [AllTheLeaks/]: Server Player Logout: 4
[19:08:19] [Server thread/INFO] [minecraft/MinecraftServer]: No leak was found so far...

died 2 times for a bear/skeleton
logged in/out 4 times

will try exploding myself like the video

[pietro-lopes]

What is your JVM args?
Are you using ZGC by any chance?

[JLUsr]

What is your JVM args? Are you using ZGC by any chance?

On the client. Yes; though, I can confirm it happens without it.
-XX:+UseZGC -XX:-ZUncommit -XX:+AlwaysPreTouch -XX:+DisableExplicitGC -XX:+ParallelRefProcEnabled -XX:+PerfDisableSharedMem

On the server. No
-Xms256M -Xmx8192M

I should also state the server is using jdk-24.0.2, I also tried Adoptium 25.0.1+8

[pietro-lopes]

Since I can't reproduce I think the best way is for you to detect it yourself.
Hop into AllTheMods discord and DM me @Uncandango so I can show you how to