Chunks get loaded while chunks are unloading leading to potential crashes
mjwells2002 opened this issue ยท 2 comments
Version Information
lithium-fabric-mc1.21-0.12.7
Expected Behavior
unloaded chunks should stay unloaded, not trigger game events that could potentially load them again
Actual Behavior
the chunks unload, and then enter a potentially endless loop of loading and unloading which could lead to a server crash
Reproduction Steps
build the shown setup with multiple mobs in a boat on a chunk boundry across to a chunk border with a sculk sensor next to it, flying away from this or otherwise unloading it will cause the chunks the setup occupied to then be loaded and unloaded every game tick
image from MCRcortex
Other Information
issue was orignally reported in the caffinemc discord in dev-lithium channel, following stack trace from our debug mod (yarn mappings) shows a case where this issue could potentially crash the server CheckingLongOpenHashSet replaces the normal LongOpenHashSet in ServerEntityManager, and you can see that remove was called while in the removeIf function
[13:09:22] [Server thread/ERROR]: IN PREDICATE REMOVAL
java.lang.Throwable: null
at me.cortex.hc_debug.Hc_debug.ERR(Hc_debug.java:15) ~[hc_debug-1.0-SNAPSHOT(1).jar:?]
at me.cortex.hc_debug.CheckingLongOpenHashSet.remove(CheckingLongOpenHashSet.java:47) ~[hc_debug-1.0-SNAPSHOT(1).jar:?]
at net.minecraft.server.world.ServerEntityManager.updateTrackingStatus(ServerEntityManager.java:236) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerEntityManager.updateTrackingStatus(ServerEntityManager.java:226) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerWorld.md6c3bd0$lithium$lambda$combineWithLithiumChunkStatusTracker$0$8(ServerWorld.java:5265) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerChunkLoadingManager.onChunkStatusChange(ServerChunkLoadingManager.java:1209) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ChunkHolder.method_31412(ChunkHolder.java:274) ~[server-intermediary.jar:?]
at java.base/java.util.concurrent.CompletableFuture$UniRun.tryFire(CompletableFuture.java:787) ~[?:?]
at java.base/java.util.concurrent.CompletableFuture$Completion.run(CompletableFuture.java:482) ~[?:?]
at net.minecraft.util.thread.ThreadExecutor.executeTask(ThreadExecutor.java:162) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerChunkManager$class_4212.executeTask(ServerChunkManager.java:552) ~[server-intermediary.jar:?]
at net.minecraft.util.thread.ThreadExecutor.runTask(ThreadExecutor.java:136) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerChunkManager$class_4212.runTask(ServerChunkManager.java:561) ~[server-intermediary.jar:?]
at net.minecraft.util.thread.ThreadExecutor.runTasks(ThreadExecutor.java:145) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerChunkManager$class_4212.runTasks(ServerChunkManager.java:525) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerChunkManager.getChunkBlocking(ServerChunkManager.java:1245) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerChunkManager.getChunk(ServerChunkManager.java:1166) ~[server-intermediary.jar:?]
at net.minecraft.world.World.getChunk(World.java:208) ~[server-intermediary.jar:?]
at net.minecraft.world.World.getChunk(World.java:5594) ~[server-intermediary.jar:?]
at net.minecraft.world.World.getBlockState(World.java:6086) ~[server-intermediary.jar:?]
at net.minecraft.world.BlockView.method_32881(BlockView.java:62) ~[server-intermediary.jar:?]
at net.minecraft.world.BlockView.raycast(BlockView.java:153) ~[server-intermediary.jar:?]
at net.minecraft.world.BlockView.raycast(BlockView.java:61) ~[server-intermediary.jar:?]
at net.minecraft.Vibrations$ListenerDataclass_8516.isOccluded(Vibrations.java:318) ~[server-intermediary.jar:?]
at net.minecraft.Vibrations$ListenerDataclass_8516.listen(Vibrations.java:269) ~[server-intermediary.jar:?]
at net.minecraft.world.event.listener.GameEventDispatchManager.method_45492(GameEventDispatchManager.java:37) ~[server-intermediary.jar:?]
at net.minecraft.world.event.listener.SimpleGameEventDispatcher.dispatch(SimpleGameEventDispatcher.java:79) ~[server-intermediary.jar:?]
at net.minecraft.world.event.listener.GameEventDispatchManager.redirect$bbn000$lithium$handleNullDispatcher(GameEventDispatchManager.java:565) ~[server-intermediary.jar:?]
at net.minecraft.world.event.listener.GameEventDispatchManager.redirect$bbn000$lithium$handleNullDispatcher$mixinextras$bridge$7(GameEventDispatchManager.java) ~[server-intermediary.jar:?]
at net.minecraft.world.event.listener.GameEventDispatchManager.dispatch(GameEventDispatchManager.java:48) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerWorld.emitGameEvent(ServerWorld.java:1002) ~[server-intermediary.jar:?]
at net.minecraft.world.WorldAccess.emitGameEvent(WorldAccess.java:111) ~[server-intermediary.jar:?]
at net.minecraft.entity.Entity.emitGameEvent(Entity.java:1218) ~[server-intermediary.jar:?]
at net.minecraft.entity.Entity.removePassenger(Entity.java:2292) ~[server-intermediary.jar:?]
at net.minecraft.entity.Entity.dismountVehicle(Entity.java:2254) ~[server-intermediary.jar:?]
at net.minecraft.entity.Entity.stopRiding(Entity.java:2259) ~[server-intermediary.jar:?]
at net.minecraft.entity.LivingEntity.stopRiding(LivingEntity.java:2963) ~[server-intermediary.jar:?]
at net.minecraft.entity.mob.MobEntity.stopRiding(MobEntity.java:2678) ~[server-intermediary.jar:?]
at com.google.common.collect.ImmutableList.forEach(ImmutableList.java:422) ~[guava-32.1.2-jre.jar:?]
at net.minecraft.entity.Entity.setRemoved(Entity.java:3708) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerEntityManager.unload(ServerEntityManager.java:333) ~[server-intermediary.jar:?]
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1709) ~[?:?]
at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:782) ~[?:?]
at net.minecraft.server.world.ServerEntityManager.method_31858(ServerEntityManager.java:319) ~[server-intermediary.jar:?]
at java.base/java.util.ArrayList.forEach(ArrayList.java:1597) ~[?:?]
at net.minecraft.server.world.ServerEntityManager.trySave(ServerEntityManager.java:300) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerEntityManager.unload(ServerEntityManager.java:316) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerEntityManager.method_31849(ServerEntityManager.java:343) ~[server-intermediary.jar:?]
at me.cortex.hc_debug.CheckingLongOpenHashSet.lambda$removeIf$0(CheckingLongOpenHashSet.java:35) ~[hc_debug-1.0-SNAPSHOT(1).jar:?]
at it.unimi.dsi.fastutil.longs.LongCollection.removeIf(LongCollection.java:274) ~[fastutil-8.5.12.jar:?]
at me.cortex.hc_debug.CheckingLongOpenHashSet.removeIf(CheckingLongOpenHashSet.java:30) ~[hc_debug-1.0-SNAPSHOT(1).jar:?]
at net.minecraft.server.world.ServerEntityManager.unloadChunks(ServerEntityManager.java:338) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerEntityManager.tick(ServerEntityManager.java:358) ~[server-intermediary.jar:?]
at net.minecraft.server.world.ServerWorld.tick(ServerWorld.java:417) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.tickWorlds(MinecraftServer.java:1021) ~[server-intermediary.jar:?]
at net.minecraft.server.dedicated.MinecraftDedicatedServer.tickWorlds(MinecraftDedicatedServer.java:299) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.tick(MinecraftServer.java:912) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.runServer(MinecraftServer.java:697) ~[server-intermediary.jar:?]
at net.minecraft.server.MinecraftServer.method_29739(MinecraftServer.java:281) ~[server-intermediary.jar:?]
at java.base/java.lang.Thread.run(Thread.java:1570) [?:?]
if the call to remove shown above happens to cause the LongOpenHashSet to resize, the server will crash with a stack trace that looks like this
---- Minecraft Crash Report ----
// On the bright side, I bought you a teddy bear!
Time: 2024-08-21 22:06:02
Description: Exception ticking world
java.lang.ArrayIndexOutOfBoundsException: Index 1709 out of bounds for length 513
at it.unimi.dsi.fastutil.longs.LongOpenHashSet$SetIterator.shiftKeys(LongOpenHashSet.java:572)
at it.unimi.dsi.fastutil.longs.LongOpenHashSet$SetIterator.remove(LongOpenHashSet.java:593)
at it.unimi.dsi.fastutil.longs.LongCollection.removeIf(LongCollection.java:275)
at net.minecraft.class_5579. (class_5579.java:338)
at net.minecraft.class_5579.method_31809(class_5579.java:358)
at net.minecraft.class_3218.method_18765(class_3218.java:417)
at net.minecraft.server.MinecraftServer.method_3813(MinecraftServer.java:1021)
at net.minecraft.class_3176.method_3813(class_3176.java:299)
at net.minecraft.server.MinecraftServer.method_3748(MinecraftServer.java:912)
at net.minecraft.server.MinecraftServer.method_29741(MinecraftServer.java:697)
at net.minecraft.server.MinecraftServer.method_29739(MinecraftServer.java:281)
at java.base/java.lang.Thread.run(Thread.java:1583)
Workaround (disabling the broken lithium optimization) is in the current releases