From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: nostalfinals <yuu8583@proton.me>
Date: Tue, 12 Mar 2024 00:36:29 +0800
Subject: [PATCH] Virtual Thread for async scheduler


diff --git a/src/main/java/org/bukkit/craftbukkit/Main.java b/src/main/java/org/bukkit/craftbukkit/Main.java
index fa843d5b5ac9e0fe8886a95246a999ac02aacd6f..b547c95d50ade495940c146ec5c39e4ef7d1d79e 100644
--- a/src/main/java/org/bukkit/craftbukkit/Main.java
+++ b/src/main/java/org/bukkit/craftbukkit/Main.java
@@ -387,7 +387,6 @@ public class Main {
             tryPreloadClass("org.bukkit.craftbukkit.scheduler.CraftScheduler$1");
             tryPreloadClass("org.bukkit.craftbukkit.scheduler.CraftScheduler$2");
             tryPreloadClass("org.bukkit.craftbukkit.scheduler.CraftScheduler$3");
-            tryPreloadClass("org.bukkit.craftbukkit.scheduler.CraftScheduler$4");
             tryPreloadClass("org.slf4j.helpers.MessageFormatter");
             tryPreloadClass("org.slf4j.helpers.FormattingTuple");
             tryPreloadClass("org.slf4j.helpers.BasicMarker");
diff --git a/src/main/java/org/bukkit/craftbukkit/scheduler/CraftAsyncScheduler.java b/src/main/java/org/bukkit/craftbukkit/scheduler/CraftAsyncScheduler.java
index 3c1992e212a6d6f1db4d5b807b38d71913619fc0..fe4f1868a5baebceb9ad0520f059ac8c4a68d397 100644
--- a/src/main/java/org/bukkit/craftbukkit/scheduler/CraftAsyncScheduler.java
+++ b/src/main/java/org/bukkit/craftbukkit/scheduler/CraftAsyncScheduler.java
@@ -38,17 +38,30 @@ import java.util.concurrent.TimeUnit;
 
 public class CraftAsyncScheduler extends CraftScheduler {
 
-    private final ThreadPoolExecutor executor = new ThreadPoolExecutor(
-            4, Integer.MAX_VALUE,30L, TimeUnit.SECONDS, new SynchronousQueue<>(),
-            new ThreadFactoryBuilder().setNameFormat("Craft Scheduler Thread - %1$d").build());
+    private final org.apache.logging.log4j.Logger LOGGER = org.apache.logging.log4j.LogManager.getLogger(getClass().getName()); // Leaf - Class logger
+    private final Executor executor; // Leaf - use super class
     private final Executor management = Executors.newSingleThreadExecutor(new ThreadFactoryBuilder()
             .setNameFormat("Craft Async Scheduler Management Thread").build());
     private final List<CraftTask> temp = new ArrayList<>();
 
     CraftAsyncScheduler() {
         super(true);
-        executor.allowCoreThreadTimeOut(true);
-        executor.prestartAllCoreThreads();
+
+        // Leaf start - Ability to use Virtual Thread for async scheduler
+        if (org.dreeam.leaf.config.modules.opt.VT4BukkitScheduler.enabled) {
+            executor = Executors.newThreadPerTaskExecutor(Thread.ofVirtual().name("Craft Scheduler Thread - ", 0).factory());
+            return;
+        }
+
+        executor = new ThreadPoolExecutor(
+                4, Integer.MAX_VALUE, 30L, TimeUnit.SECONDS, new SynchronousQueue<>(),
+                new ThreadFactoryBuilder().setNameFormat("Craft Scheduler Thread - %1$d").setUncaughtExceptionHandler(new net.minecraft.DefaultUncaughtExceptionHandlerWithName(net.minecraft.server.MinecraftServer.LOGGER)).build());
+
+        var threadPoolExecutor = (ThreadPoolExecutor) executor;
+
+        threadPoolExecutor.allowCoreThreadTimeOut(true);
+        threadPoolExecutor.prestartAllCoreThreads();
+        // Leaf end - Ability to use Virtual Thread for async scheduler
     }
 
     @Override
diff --git a/src/main/java/org/dreeam/leaf/config/modules/opt/VT4BukkitScheduler.java b/src/main/java/org/dreeam/leaf/config/modules/opt/VT4BukkitScheduler.java
new file mode 100644
index 0000000000000000000000000000000000000000..0c6b4555c615bd918fc8c0a597b31b7f9f05f629
--- /dev/null
+++ b/src/main/java/org/dreeam/leaf/config/modules/opt/VT4BukkitScheduler.java
@@ -0,0 +1,29 @@
+package org.dreeam.leaf.config.modules.opt;
+
+import com.electronwill.nightconfig.core.file.CommentedFileConfig;
+import org.dreeam.leaf.config.ConfigInfo;
+import org.dreeam.leaf.config.EnumConfigCategory;
+import org.dreeam.leaf.config.IConfigModule;
+
+public class VT4BukkitScheduler implements IConfigModule {
+
+    @Override
+    public EnumConfigCategory getCategory() {
+        return EnumConfigCategory.PERFORMANCE;
+    }
+
+    @Override
+    public String getBaseName() {
+        return "use_virtual_thread_for_async_scheduler";
+    }
+
+    @ConfigInfo(baseName = "enabled")
+    public static boolean enabled = true;
+
+    @Override
+    public void onLoaded(CommentedFileConfig config) {
+        config.setComment("performance.use_virtual_thread_for_async_scheduler", """
+                 Use the new Virtual Thread introduced in JDK 21 for CraftAsyncScheduler.
+                """);
+    }
+}