From 74cc5505b021aab0e0b8f1552200d146a13656ad Mon Sep 17 00:00:00 2001
From: Xiao-no-love <140927721+Xiao-no-love@users.noreply.github.com>
Date: Tue, 13 Oct 2026 18:28:28 +0800
Subject: [PATCH] =?UTF-8?q?fix(mixin):=20=E5=AD=90=E4=BB=BB=E5=8A=A1?=
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根因：Level.updateNeighbourForOutputSignal 遍历6方向，第一格邻居有 hasChunkAt 守卫，
但若第一格是红石导体，会再往外取第二格(blockpos.relative(direction))并直接 getBlockState
——没有 hasChunkAt 守卫。原版主线程会按需同步生成区块；DR 细粒度子任务线程上则触发
ServerChunkCacheMixin.modzuozhi_subtaskSafeGetChunk 的 required=true 未命中分支，
抛 IllegalStateException + FaultGuard 降级。异常被 LevelChunk$BoundTickingBlockEntity.tick
崩溃保护包成 CrashReport("Ticking block entity")，同时细粒度被关 → 跑图卡顿。

实测：18:10:03 trial_spawner(-6765,-15,1376) tick 时 setChanged → updateNeighbourForOutputSignal
→ 第二格 getBlockState(chunk=-423,85 未加载) → 崩。

修复：新增 LevelNeighbourSignalGuardMixin，@WrapOperation 拦第二格 getBlockState(ordinal=1)，
子任务线程 + !hasChunkAt 时返回 VOID_AIR（getWeakChanges=false，不传播红石信号），
与 getBlockState 越界分支语义一致。主线程/维度 worker 行为不变。

参考：Folia 对 updateNeighbourForOutputSignal 加加载守卫的同类修复思路。
---
 .../mixin/LevelNeighbourSignalGuardMixin.java | 45 +++++++++++++++++++
 .../resources/dimensionalripper.mixins.json   |  1 +
 2 files changed, 46 insertions(+)
 create mode 100644 src/main/java/dev/modzuozhi/mixin/LevelNeighbourSignalGuardMixin.java

diff --git a/src/main/java/dev/modzuozhi/mixin/LevelNeighbourSignalGuardMixin.java b/src/main/java/dev/modzuozhi/mixin/LevelNeighbourSignalGuardMixin.java
new file mode 100644
index 0000000..67ed3c0
--- /dev/null
+++ b/src/main/java/dev/modzuozhi/mixin/LevelNeighbourSignalGuardMixin.java
@@ -0,0 +1,45 @@
+package dev.modzuozhi.mixin;
+
+import com.llamalad7.mixinextras.injector.wrapoperation.Operation;
+import com.llamalad7.mixinextras.injector.wrapoperation.WrapOperation;
+import dev.modzuozhi.core.dimthread.FineGrainScheduler;
+import net.minecraft.core.BlockPos;
+import net.minecraft.world.level.BlockGetter;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.level.block.state.BlockState;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+
+/**
+ * 修复细粒度子任务线程上 {@code Level.updateNeighbourForOutputSignal} 触发未加载区块同步生成导致崩溃。
+ * <p>
+ * 原版该方法遍历 6 个方向：第一格邻居用 {@code hasChunkAt} 守卫，但<strong>若第一格是红石导体，
+ * 会再往外取第二格</strong>（{@code blockpos.relative(direction)}）并直接 {@code getBlockState}——<strong>没有 hasChunkAt 守卫</strong>。
+ * 原版主线程上这个 {@code getBlockState} 会按需同步生成/加载区块；但在 DR 细粒度子任务线程上，
+ * {@code ServerChunkCacheMixin.modzuozhi_subtaskSafeGetChunk} 检测到 required=true 未命中，
+ * 会抛 {@code IllegalStateException}（并触发 {@link dev.modzuozhi.core.dimthread.FaultGuard} 降级）。
+ * 该异常被 {@code LevelChunk$BoundTickingBlockEntity.tick} 的崩溃保护包成 CrashReport，
+ * 表现为"Ticking block entity"崩溃 + 细粒度被关 → 跑图卡顿。
+ * <p>
+ * 修复：拦第二格的 {@code getBlockState}（ordinal=1）。目标区块未加载时返回 {@code VOID_AIR}
+ * （与 {@code getBlockState} 越界分支语义一致：{@code VOID_AIR.getWeakChanges} 为 false，
+ * 不会触发 {@code neighborChanged}，等价"该方向无红石信号传播"），避免子任务线程请求同步生成。
+ * <p>
+ * 仅在子任务线程生效；主线程/维度 worker 行为完全不变。
+ */
+@Mixin(Level.class)
+public abstract class LevelNeighbourSignalGuardMixin {
+
+    @WrapOperation(method = "updateNeighbourForOutputSignal",
+            at = @At(value = "INVOKE",
+                    target = "Lnet/minecraft/world/level/Level;getBlockState(Lnet/minecraft/core/BlockPos;)Lnet/minecraft/world/level/block/state/BlockState;",
+                    ordinal = 1))
+    private BlockState modzuozhi_guardSecondNeighbour(Level level, BlockPos pos, Operation<BlockState> original) {
+        if (FineGrainScheduler.inSubTask() && !level.hasChunkAt(pos)) {
+            // 未加载的第二格邻居：不请求同步生成，返回 VOID_AIR（getWeakChanges=false，不传播信号）。
+            return Blocks.VOID_AIR.defaultBlockState();
+        }
+        return original.call(level, pos);
+    }
+}
\ No newline at end of file
diff --git a/src/main/resources/dimensionalripper.mixins.json b/src/main/resources/dimensionalripper.mixins.json
index 2bc3880..1b90662 100644
--- a/src/main/resources/dimensionalripper.mixins.json
+++ b/src/main/resources/dimensionalripper.mixins.json
@@ -38,6 +38,7 @@
         "LevelGetChunkMixin",
         "LevelMixin",
         "LevelRandomMixin",
+        "LevelNeighbourSignalGuardMixin",
         "LevelTicksMixin",
         "LivingEntityGetInBlockStateMixin",
         "MinecraftServerDimMixin",