From 5e1a37f1e3c7d96e222876e5f3d5d61200774b83 Mon Sep 17 00:00:00 2001
From: Arbousier1 <elderli@foxmail.com>
Date: Sat, 18 Jul 2026 11:27:16 +0800
Subject: [PATCH] perf(runtime): cache Folia global and region scheduler
 instances
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globalRegionScheduler() and regionScheduler() previously invoked a
reflective method lookup on plugin.getServer() on every call. On Folia,
these return stable singleton schedulers that do not change for the
lifetime of the server. Cache the resolved scheduler in a volatile field
on first successful lookup so subsequent calls skip the reflective
invokeNoArgs path entirely.

In the benchmark Folia burst (84 tasks), this eliminates 19 reflective
scheduler lookups per invocation (4 runGlobal + 16 runRegion, minus the
first call each that populates the cache). On Paper, where these methods
do not exist and invokeNoArgs returns null, the cache stays empty and
the behavior is unchanged — null is never cached so the lookup still
runs each time, preserving the existing fallback-to-BukkitScheduler
semantics.

entityScheduler(Entity) is not cached because the target entity varies
per call and there is no stable key to cache on.
---
 .../mahjong/runtime/ServerScheduler.java      | 22 +++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/main/java/top/ellan/mahjong/runtime/ServerScheduler.java b/src/main/java/top/ellan/mahjong/runtime/ServerScheduler.java
index 7a984b0..602917e 100644
--- a/src/main/java/top/ellan/mahjong/runtime/ServerScheduler.java
+++ b/src/main/java/top/ellan/mahjong/runtime/ServerScheduler.java
@@ -90,6 +90,8 @@ public boolean isCancelled() {
     };
 
     private final Plugin plugin;
+    private volatile Object cachedGlobalRegionScheduler;
+    private volatile Object cachedRegionScheduler;
 
     public ServerScheduler(Plugin plugin) {
         this.plugin = Objects.requireNonNull(plugin, "plugin");
@@ -313,11 +315,27 @@ public PluginTask removeEntity(Entity entity, long delayTicks) {
     }
 
     private Object globalRegionScheduler() {
-        return this.invokeNoArgs(this.plugin.getServer(), GET_GLOBAL_REGION_SCHEDULER);
+        Object cached = this.cachedGlobalRegionScheduler;
+        if (cached != null) {
+            return cached;
+        }
+        Object resolved = this.invokeNoArgs(this.plugin.getServer(), GET_GLOBAL_REGION_SCHEDULER);
+        if (resolved != null) {
+            this.cachedGlobalRegionScheduler = resolved;
+        }
+        return resolved;
     }
 
     private Object regionScheduler() {
-        return this.invokeNoArgs(this.plugin.getServer(), GET_REGION_SCHEDULER);
+        Object cached = this.cachedRegionScheduler;
+        if (cached != null) {
+            return cached;
+        }
+        Object resolved = this.invokeNoArgs(this.plugin.getServer(), GET_REGION_SCHEDULER);
+        if (resolved != null) {
+            this.cachedRegionScheduler = resolved;
+        }
+        return resolved;
     }
 
     private Object entityScheduler(Entity entity) {