From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Spottedleaf <Spottedleaf@users.noreply.github.com> Date: Sat, 12 Mar 2022 06:31:13 -0800 Subject: [PATCH] Fix swamp hut cat generation deadlock The worldgen thread will attempt to get structure references via the world's getChunkAt method, which is fine if the gen is not cancelled - but if the chunk was unloaded, the call will block indefinitely. Instead of using the world state, we use the already supplied ServerLevelAccessor which will always have the chunk available. diff --git a/src/main/java/net/minecraft/world/entity/animal/Cat.java b/src/main/java/net/minecraft/world/entity/animal/Cat.java index f3a991aa878f3b29fdc525ecdde6766efb5e129c..5a86530c65d7d83e4608600a04ffd931bf59dc4a 100644 --- a/src/main/java/net/minecraft/world/entity/animal/Cat.java +++ b/src/main/java/net/minecraft/world/entity/animal/Cat.java @@ -366,7 +366,7 @@ public class Cat extends TamableAnimal implements VariantHolder<Holder<CatVarian BuiltInRegistries.CAT_VARIANT.getRandomElementOf(tagkey, world.getRandom()).ifPresent(this::setVariant); ServerLevel worldserver = world.getLevel(); - if (worldserver.structureManager().getStructureWithPieceAt(this.blockPosition(), StructureTags.CATS_SPAWN_AS_BLACK).isValid()) { + if (worldserver.structureManager().getStructureWithPieceAt(this.blockPosition(), StructureTags.CATS_SPAWN_AS_BLACK, world).isValid()) { // Paper - Fix swamp hut cat generation deadlock this.setVariant((Holder) BuiltInRegistries.CAT_VARIANT.getOrThrow(CatVariant.ALL_BLACK)); this.setPersistenceRequired(); } diff --git a/src/main/java/net/minecraft/world/level/StructureManager.java b/src/main/java/net/minecraft/world/level/StructureManager.java index 3d607ac74de4bc051ab68269dbab0bbd3a52dc54..03adb02297911e5a5051edac14453d7e3eeac29c 100644 --- a/src/main/java/net/minecraft/world/level/StructureManager.java +++ b/src/main/java/net/minecraft/world/level/StructureManager.java @@ -48,7 +48,12 @@ public class StructureManager { } public List<StructureStart> startsForStructure(ChunkPos pos, Predicate<Structure> predicate) { - Map<Structure, LongSet> map = this.level.getChunk(pos.x, pos.z, ChunkStatus.STRUCTURE_REFERENCES).getAllReferences(); + // Paper start - Fix swamp hut cat generation deadlock + return this.startsForStructure(pos, predicate, null); + } + public List<StructureStart> startsForStructure(ChunkPos pos, Predicate<Structure> predicate, @Nullable ServerLevelAccessor levelAccessor) { + Map<Structure, LongSet> map = (levelAccessor == null ? this.level : levelAccessor).getChunk(pos.x, pos.z, ChunkStatus.STRUCTURE_REFERENCES).getAllReferences(); + // Paper end - Fix swamp hut cat generation deadlock Builder<StructureStart> builder = ImmutableList.builder(); for (Entry<Structure, LongSet> entry : map.entrySet()) { @@ -116,10 +121,20 @@ public class StructureManager { } public StructureStart getStructureWithPieceAt(BlockPos pos, Predicate<Holder<Structure>> predicate) { + // Paper start - Fix swamp hut cat generation deadlock + return this.getStructureWithPieceAt(pos, predicate, null); + } + + public StructureStart getStructureWithPieceAt(BlockPos pos, TagKey<Structure> tag, @Nullable ServerLevelAccessor levelAccessor) { + return this.getStructureWithPieceAt(pos, structure -> structure.is(tag), levelAccessor); + } + + public StructureStart getStructureWithPieceAt(BlockPos pos, Predicate<Holder<Structure>> predicate, @Nullable ServerLevelAccessor levelAccessor) { + // Paper end - Fix swamp hut cat generation deadlock Registry<Structure> registry = this.registryAccess().lookupOrThrow(Registries.STRUCTURE); for (StructureStart structureStart : this.startsForStructure( - new ChunkPos(pos), structure -> registry.get(registry.getId(structure)).map(predicate::test).orElse(false) + new ChunkPos(pos), structure -> registry.get(registry.getId(structure)).map(predicate::test).orElse(false), levelAccessor // Paper - Fix swamp hut cat generation deadlock )) { if (this.structureHasPieceAt(pos, structureStart)) { return structureStart;