remove threaded chunkloading support

Can easily be re-added when needed. But at the moment there is no mod that introduces threaded chunkloading (from what I know).
Fixes #14, #15

Author: Pilzinsel64

src/main/java/de/pilz/alternativechunkloading/AlternativeChunkloading.java

@@ -1,7 +1,5 @@
 package de.pilz.alternativechunkloading;
 
-import java.util.ArrayList;
-
 import net.minecraftforge.common.MinecraftForge;
 
 import org.apache.logging.log4j.LogManager;
@@ -23,7 +21,7 @@ public class AlternativeChunkloading {
     public static final String MODID = "alternativechunkloading";
     public static final Logger LOG = LogManager.getLogger(MODID);
 
-    public static final ArrayList<Long> ignoreThreads = new ArrayList<>();
+    public static Internals internals = new Internals();
 
     EventHandler eventHandler;
 

src/main/java/de/pilz/alternativechunkloading/Internals.java

@@ -0,0 +1,6 @@
+package de.pilz.alternativechunkloading;
+
+public class Internals {
+
+    public boolean isPopulating;
+}

src/main/java/de/pilz/alternativechunkloading/mixins/early/minecraft/MixinChunk.java

@@ -16,10 +16,8 @@ public class MixinChunk {
     @WrapMethod(method = "populateChunk")
     private void populateChunk(IChunkProvider p_76624_1_, IChunkProvider p_76624_2_, int p_76624_3_, int p_76624_4_,
         Operation<Void> original) {
-        long thread = Thread.currentThread()
-            .getId();
-        AlternativeChunkloading.ignoreThreads.add(thread);
+        AlternativeChunkloading.internals.isPopulating = true;
         original.call(p_76624_1_, p_76624_2_, p_76624_3_, p_76624_4_);
-        AlternativeChunkloading.ignoreThreads.remove(thread);
+        AlternativeChunkloading.internals.isPopulating = false;
     }
 }

src/main/java/de/pilz/alternativechunkloading/mixins/early/minecraft/MixinChunkProviderServer.java

@@ -20,8 +20,6 @@ public abstract class MixinChunkProviderServer {
             target = "Lnet/minecraft/world/gen/ChunkProviderServer;loadChunkOnProvideRequest:Z",
             opcode = Opcodes.GETFIELD))
     private boolean alternativechunkloading$provideChunk$allowChunkload(boolean original) {
-        return original || AlternativeChunkloading.ignoreThreads.contains(
-            Thread.currentThread()
-                .getId());
+        return original || AlternativeChunkloading.internals.isPopulating;
     }
 }