Fix concurrency issues in vanilla RegistryOps.memoizeLookup

Author: embeddedt

common/src/main/java/org/embeddedt/modernfix/common/mixin/bugfix/registry_ops_cme/RegistryOpsMemoizedMixin.java

@@ -0,0 +1,27 @@
+package org.embeddedt.modernfix.common.mixin.bugfix.registry_ops_cme;
+
+import net.minecraft.core.Registry;
+import net.minecraft.resources.RegistryOps;
+import net.minecraft.resources.ResourceKey;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
+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.CallbackInfo;
+
+import java.util.Map;
+import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
+
+@Mixin(targets = {"net/minecraft/resources/RegistryOps$1"})
+public class RegistryOpsMemoizedMixin {
+    @Shadow @Final @Mutable
+    private Map<ResourceKey<? extends Registry<?>>, Optional<? extends RegistryOps.RegistryInfo<?>>> lookups;
+
+    @Inject(method = "<init>", at = @At("RETURN"))
+    private void useConcurrentMap(RegistryOps.RegistryInfoLookup registryInfoLookup, CallbackInfo ci) {
+        this.lookups = new ConcurrentHashMap<>(this.lookups);
+    }
+}