Server Implementation

Paper

Server Version

1.19.3

Describe the bug

Creating and deleting worlds seem to have memory leak, while using FAWE.
Also, for some strange reason adapter is created for two different versions.

I'm creating plugin that creates world, pastes schematic and after some time it deletes that world.

I've found this thread on PaperMC github, its similar issue redirected to FAWE, but I havent found any follow up here. PaperMC/Paper#9199

Two heapdumps with this issue are here: https://skyup.pl/public/heapdumps/
One of them is smaller, but still show many worlds.

To Reproduce

The only API I'm using from FAWE is this:

// Create session with world adapting
EditSession editSession = WorldEdit.getInstance().newEditSession(BukkitAdapter.adapt(world)); 

// Loading schematic
String schematicName = "..." // some schematic name
File file = new File(Main.getInstance().getDataFolder(), "/schematics/"+schematicName);
ClipboardFormat format = ClipboardFormats.findByFile(file);
ClipboardReader reader = format.getReader(new FileInputStream(file));
Clipboard clipboard = reader.read();
ClipboardHolder clipboard =  new ClipboardHolder(clipboard);

// Transforming schematic
double dt = //some transformation
clipboard.setTransform(new AffineTransform().rotateY(dt));

//Pasting schematic
Operations.complete(clipboard.createPaste(editSession)
        .to(BlockVector3.at(x, Main.getSettings().getDungeonY(), z))
        .ignoreAirBlocks(true)
        .build());

//Closing session
editSession.close();

Expected behaviour

To not have memory leak

Screenshots / Videos

MAT schows 17 WorldServer objects loaded, but most of them are already deleted worlds.
I'm not using any regeneration.

Error log (if applicable)

No response

Fawe Debugpaste

https://athion.net/ISPaster/paste/view/73d68e815ca944d39e098438a0e1185b

Fawe Version

FastAsyncWorldEdit version 2.6.3-SNAPSHOT-468;152d870

Checklist

• I have included a Fawe debugpaste.
• I am using the newest build from https://ci.athion.net/job/FastAsyncWorldEdit/ and the issue still persists.

Anything else?

No response

That is hard to reproduce with 73 other plugins, purpur instead of paper in 1.19.3 (newest is 1.19.4) and this kind of issue with your plugin:

[21:07:06] [Server thread/INFO]: Could not set generator for world 'dungeon_325_egzekucja_': Plugin '2;0;1;' does not exist

Can you test only with FAWE and redo it with your plugin with the mentioned api?

I've found the issue. It was not FAWE, but MythicMobs. More specifically its RandomSpawningManager generatedSpawnPoints HashMap not removing world on unload.