From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Bjarne Koll <lynxplay101@gmail.com>
Date: Sun, 19 Feb 2023 16:14:28 +0100
Subject: [PATCH] Optimize spigot event bus

This patch contains a lot of small optimizations to the spigot event bus
to improve its speed as much as possible, allowing for a large amount of
events to be published by the server without impacting the overall
performance too much.

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..40226500e36b3b545003ed2c27bc6a096e7f4079 100644
--- a/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
+++ b/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
@@ -36,11 +36,17 @@ 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.");
+        // KTP start - Optimise spigot event bus
+        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.");
+            }
         }
+        // KTP stop - Optimise spigot event bus
 
         HandlerList handlers = event.getHandlers();
         RegisteredListener[] listeners = handlers.getRegisteredListeners();