fix: prevent async save and saveAll

c2me-fixes-general-threading-issues/src/main/java/com/ishland/c2me/fixes/general/threading_issues/mixin/asynccatchers/MixinMinecraftServer.java

@@ -0,0 +1,36 @@
+package com.ishland.c2me.fixes.general.threading_issues.mixin.asynccatchers;
+
+import net.minecraft.server.MinecraftServer;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import java.util.ConcurrentModificationException;
+
+@Mixin(MinecraftServer.class)
+public class MixinMinecraftServer {
+
+    @Shadow @Final private Thread serverThread;
+
+    @Inject(method = "save", at = @At("HEAD"))
+    private void preventAsyncSave(CallbackInfoReturnable<Boolean> cir) {
+        if (Thread.currentThread() != this.serverThread) {
+            final ConcurrentModificationException exception = new ConcurrentModificationException("Attempted to call MinecraftServer#save async");
+            exception.printStackTrace();
+            throw exception;
+        }
+    }
+
+    @Inject(method = "saveAll", at = @At("HEAD"))
+    private void preventAsyncSaveAll(CallbackInfoReturnable<Boolean> cir) {
+        if (Thread.currentThread() != this.serverThread) {
+            final ConcurrentModificationException exception = new ConcurrentModificationException("Attempted to call MinecraftServer#saveAll async");
+            exception.printStackTrace();
+            throw exception;
+        }
+    }
+
+}

c2me-fixes-general-threading-issues/src/main/resources/c2me-fixes-general-threading-issues.mixins.json

@@ -7,6 +7,7 @@
     "MixinChunkHolder",
     "MixinChunkTicketManager",
     "MixinThreadedAnvilChunkStorage",
+    "asynccatchers.MixinMinecraftServer",
     "asynccatchers.MixinServerChunkManager"
   ]
 }