From 0721e3cc751e98250954cf5a68df54269dc4aa07 Mon Sep 17 00:00:00 2001
From: md_5 <md_5@live.com.au>
Date: Thu, 31 Jan 2013 17:55:46 +1100
Subject: [PATCH] Sweet trick to avoid locking in global tab list, basically
 reimplement HashSet based on a ConcurrentHashMap.

---
 .../net/md_5/bungee/tablist/GlobalTabList.java    | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/proxy/src/main/java/net/md_5/bungee/tablist/GlobalTabList.java b/proxy/src/main/java/net/md_5/bungee/tablist/GlobalTabList.java
index b622e27c..b563ebd1 100644
--- a/proxy/src/main/java/net/md_5/bungee/tablist/GlobalTabList.java
+++ b/proxy/src/main/java/net/md_5/bungee/tablist/GlobalTabList.java
@@ -1,8 +1,7 @@
 package net.md_5.bungee.tablist;
 
-import java.util.HashSet;
-import java.util.Set;
-import lombok.Synchronized;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 import net.md_5.bungee.BungeeCord;
 import net.md_5.bungee.UserConnection;
 import net.md_5.bungee.api.ProxyServer;
@@ -13,7 +12,9 @@ import net.md_5.bungee.packet.PacketC9PlayerListItem;
 public class GlobalTabList implements TabListHandler
 {
 
-    private final Set<ProxiedPlayer> sentPings = new HashSet<>();
+    // Sweet trick to avoid locking, basically reimplement HashSet based on a ConcurrentHashMap
+    private static final Object PRESENT = new Object();
+    private final Map<ProxiedPlayer, Object> sentPings = new ConcurrentHashMap<>();
 
     @Override
     public void onConnect(ProxiedPlayer player)
@@ -27,18 +28,16 @@ public class GlobalTabList implements TabListHandler
     }
 
     @Override
-    @Synchronized(value = "sentPings")
     public void onPingChange(ProxiedPlayer player, int ping)
     {
-        if (!sentPings.contains(player))
+        if (!sentPings.containsKey(player))
         {
             BungeeCord.getInstance().broadcast(new PacketC9PlayerListItem(player.getDisplayName(), true, player.getPing()));
-            sentPings.add(player);
+            sentPings.put(player, PRESENT);
         }
     }
 
     @Override
-    @Synchronized(value = "sentPings")
     public void onDisconnect(ProxiedPlayer player)
     {
         BungeeCord.getInstance().broadcast(new PacketC9PlayerListItem(player.getDisplayName(), false, 9999));