From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: NanaChiyo0721 <nanachiyo0721@163.com>
Date: Wed, 12 Aug 2026 16:31:01 +0800
Subject: [PATCH] Fix thread unsafe collections use in PlayerList


diff --git a/net/minecraft/server/players/PlayerList.java b/net/minecraft/server/players/PlayerList.java
index 259eb7574841b1b885093b534440f8a40db4e8e2..c70d3169002681c5f2131ca8e98ef7d42c6dc4fa 100644
--- a/net/minecraft/server/players/PlayerList.java
+++ b/net/minecraft/server/players/PlayerList.java
@@ -132,7 +132,7 @@ public abstract class PlayerList {
 
     // CraftBukkit start
     private org.bukkit.craftbukkit.CraftServer cserver;
-    private final Map<String,ServerPlayer> playersByName = new java.util.HashMap<>();
+    private final Map<String,ServerPlayer> playersByName = new java.util.concurrent.ConcurrentHashMap<>(); // Folia - region threading - change to CHM - Note: we do NOT expect concurrency PER KEY!
     public @Nullable String collideRuleTeamName; // Paper - Configurable player collision
 
     // Folia start - region threading