From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: wangxyper <wangxyper@163.com>
Date: Sat, 28 Jan 2023 13:05:13 +0800
Subject: [PATCH] MikuServer: Fix threading issue in event system

Original license: MIT
Original project: https://github.com/MikuMC/MikuServer

diff --git a/src/main/java/org/bukkit/Server.java b/src/main/java/org/bukkit/Server.java
index 236aa2c1841eef6ca723a809b1632894bebf0b67..3fa5b8740f6c5cbfd55dfc908225301d6d292c0b 100644
--- a/src/main/java/org/bukkit/Server.java
+++ b/src/main/java/org/bukkit/Server.java
@@ -113,6 +113,8 @@ public interface Server extends PluginMessageRecipient, net.kyori.adventure.audi
     @NotNull
     public String getBukkitVersion();
 
+    public boolean isCurrentThreadWorker();
+
     // Paper start - expose game version
     /**
      * Gets the version of game this server implements
diff --git a/src/main/java/org/bukkit/plugin/SimplePluginManager.java b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
index 730394fd53fdaa90133ee399f86e76da8ccc08e6..14d05c364fe11941045e1f24bcc00c0e78d34fe7 100644
--- a/src/main/java/org/bukkit/plugin/SimplePluginManager.java
+++ b/src/main/java/org/bukkit/plugin/SimplePluginManager.java
@@ -646,6 +646,8 @@ public final class SimplePluginManager implements PluginManager {
     }
     private void fireEvent(Event event) { callEvent(event); } // Paper - support old method incase plugin uses reflection
 
+    private final Object eventLock = new Object();
+
     /**
      * Calls an event with the given details.
      *
@@ -672,6 +674,19 @@ public final class SimplePluginManager implements PluginManager {
         }
         // KTP end - optimize spigot event bus
 
+        if (server.isCurrentThreadWorker()) {
+            synchronized (this.eventLock) {
+                this.callEventInternal(event);
+                return;
+            }
+        }
+
+        this.callEventInternal(event);
+    }
+
+    private void callEventInternal(Event event) {
+        HandlerList handlers = event.getHandlers();
+        RegisteredListener[] listeners = handlers.getRegisteredListeners();
         for (RegisteredListener registration : listeners) {
             if (!registration.getPlugin().isEnabled()) {
                 continue;
@@ -690,7 +705,7 @@ public final class SimplePluginManager implements PluginManager {
                             plugin.getDescription().getAuthors(),
                             plugin.getDescription().getFullName(),
                             ex.getMessage()
-                            ));
+                    ));
                 }
             } catch (Throwable ex) {
                 // Paper start - error reporting