Separate PerChunkThreadProvider from PerInstanceThreadProvider, support arbitrary ThreadProvider#findThread number

src/main/java/net/minestom/server/UpdateManager.java

@@ -39,8 +39,8 @@ public final class UpdateManager {
 
     {
         // DEFAULT THREAD PROVIDER
-        //threadProvider = new PerGroupChunkProvider();
         threadProvider = new PerInstanceThreadProvider(4);
+        //threadProvider = new PerChunkThreadProvider(4);
     }
 
     /**

src/main/java/net/minestom/server/entity/Player.java

@@ -327,6 +327,7 @@ public class Player extends LivingEntity implements CommandSender, Localizable,
             packet.process(this);
         }
 
+        //System.out.println(getAcquiredElement().getHandler().getBatchThread());
         Collection<Acquirable<Player>> players = new ArrayList<>();
         //if (username.equals("TheMode911"))
         for (Player p1 : MinecraftServer.getConnectionManager().getOnlinePlayers()) {

src/main/java/net/minestom/server/thread/PerChunkThreadProvider.java

@@ -0,0 +1,20 @@
+package net.minestom.server.thread;
+
+import net.minestom.server.instance.Chunk;
+import net.minestom.server.utils.chunk.ChunkUtils;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Each {@link Chunk} gets assigned to a random thread.
+ */
+public class PerChunkThreadProvider extends ThreadProvider {
+
+    public PerChunkThreadProvider(int threadCount) {
+        super(threadCount);
+    }
+
+    @Override
+    public long findThread(@NotNull Chunk chunk) {
+        return ChunkUtils.getChunkIndex(chunk.getChunkX(), chunk.getChunkZ());
+    }
+}

src/main/java/net/minestom/server/thread/PerInstanceThreadProvider.java

@@ -1,10 +1,12 @@
 package net.minestom.server.thread;
 
 import net.minestom.server.instance.Chunk;
+import net.minestom.server.instance.Instance;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.concurrent.ThreadLocalRandom;
-
+/**
+ * Each {@link Instance} gets assigned to a random thread.
+ */
 public class PerInstanceThreadProvider extends ThreadProvider {
 
     public PerInstanceThreadProvider(int threadCount) {
@@ -12,7 +14,7 @@ public class PerInstanceThreadProvider extends ThreadProvider {
     }
 
     @Override
-    public int findThread(@NotNull Chunk chunk) {
-        return ThreadLocalRandom.current().nextInt(getThreads().size());
+    public long findThread(@NotNull Chunk chunk) {
+        return System.identityHashCode(chunk.getInstance());
     }
-}
+}

src/main/java/net/minestom/server/thread/ThreadProvider.java

@@ -57,10 +57,10 @@ public abstract class ThreadProvider {
      *
      * @param chunk the chunk
      */
-    public abstract int findThread(@NotNull Chunk chunk);
+    public abstract long findThread(@NotNull Chunk chunk);
 
     protected void addChunk(Chunk chunk) {
-        int threadId = findThread(chunk);
+        final int threadId = (int) (Math.abs(findThread(chunk)) % threads.size());
         BatchThread thread = threads.get(threadId);
         var chunks = threadChunkMap.computeIfAbsent(thread, batchThread -> ConcurrentHashMap.newKeySet());