From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: NONPLAYT <76615486+NONPLAYT@users.noreply.github.com>
Date: Sun, 25 Jun 2023 13:38:03 +0300
Subject: [PATCH] Optimize Paper Event Manager

Original project: lynxplay/ktp
Link: https://github.com/lynxplay/ktp
Modified by NONPLAYT

diff --git a/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java b/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
index 7ce9ebba8ce304d1f3f21d4f15ee5f3560d7700b..0e3bed7a75f8f4611f9f44a1f78fd70cc06eaa54 100644
--- a/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
+++ b/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
@@ -36,14 +36,21 @@ class PaperEventManager {
 
     // SimplePluginManager
     public void callEvent(@NotNull Event event) {
-        if (event.isAsynchronous() && this.server.isPrimaryThread()) {
-            throw new IllegalStateException(event.getEventName() + " may only be triggered asynchronously.");
-        } else if (!event.isAsynchronous() && !this.server.isPrimaryThread() && !this.server.isStopping()) {
-            throw new IllegalStateException(event.getEventName() + " may only be triggered synchronously.");
-        }
-
+        // DivineMC start - Optimize Paper Event Manager
         HandlerList handlers = event.getHandlers();
         RegisteredListener[] listeners = handlers.getRegisteredListeners();
+        if (listeners.length == 0) return;
+
+        if (event.asynchronous() != net.kyori.adventure.util.TriState.NOT_SET) {
+            final boolean onPrimaryThread = this.server.isPrimaryThread();
+            final boolean isAsync = event.isAsynchronous();
+            if (isAsync && onPrimaryThread) {
+                throw new IllegalStateException(event.getEventName() + " may only be triggered asynchronously.");
+            } else if (!isAsync && !onPrimaryThread && !this.server.isStopping()) {
+                throw new IllegalStateException(event.getEventName() + " may only be triggered synchronously.");
+            }
+        }
+        // DivineMC end
 
         for (RegisteredListener registration : listeners) {
             if (!registration.getPlugin().isEnabled()) {