PaperMC/CraftBukkit-Patches/0072-Configurable-Amount-of-Netty-Threads.patch

From a9ac8accb027efbd0292d9d4e185a3c017c40054 Mon Sep 17 00:00:00 2001
From: md_5 <git@md-5.net>
Date: Fri, 13 Dec 2013 11:58:58 +1100
Subject: [PATCH] Configurable Amount of Netty Threads

This brings back the option that the Spigot version of netty saw. By default Netty will try and use cores*2 threads, however if running multiple servers on the same machine, this can be too many threads. Additionally some people have 16 core servers. If 32 Netty threads are allowed in this setup, then the lock contention, and thus blocking between threads becomes much greater, leading to decreased performance.

diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index a55160f..ccf7abd 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -51,7 +51,7 @@ public abstract class MinecraftServer implements ICommandListener, Runnable, IMo
     private final List m = new ArrayList();
     private final ICommandHandler n;
     public final MethodProfiler methodProfiler = new MethodProfiler();
-    private final ServerConnection o;
+    private ServerConnection o; // Spigot
     private final ServerPing p = new ServerPing();
     private final Random q = new Random();
     private String serverIp;
@@ -111,7 +111,7 @@ public abstract class MinecraftServer implements ICommandListener, Runnable, IMo
         i = this;
         this.c = proxy;
         // this.universe = file1; // CraftBukkit
-        this.o = new ServerConnection(this);
+        // this.o = new ServerConnection(this); // Spigot
         this.n = new CommandDispatcher();
         // this.convertable = new WorldLoaderServer(file1); // CraftBukkit - moved to DedicatedServer.init
         this.S = (new YggdrasilAuthenticationService(proxy, UUID.randomUUID().toString())).createMinecraftSessionService();
@@ -1219,7 +1219,7 @@ public abstract class MinecraftServer implements ICommandListener, Runnable, IMo
     }
 
     public ServerConnection ag() {
-        return this.o;
+        return ( this.o ) == null ? this.o = new ServerConnection( this ) : this.o; // Spigot
     }
 
     public boolean ai() {
diff --git a/src/main/java/org/spigotmc/SpigotConfig.java b/src/main/java/org/spigotmc/SpigotConfig.java
index acd5567..c4a5488 100644
--- a/src/main/java/org/spigotmc/SpigotConfig.java
+++ b/src/main/java/org/spigotmc/SpigotConfig.java
@@ -197,4 +197,11 @@ public class SpigotConfig
         }
         bungee = getBoolean( "settings.bungeecord", false );
     }
+
+    private static void nettyThreads()
+    {
+        int count = getInt( "settings.netty-threads", 4 );
+        System.setProperty( "io.netty.eventLoopThreads", Integer.toString( count ) );
+        Bukkit.getLogger().log( Level.INFO, "Using {0} threads for Netty based IO", count );
+    }
 }
-- 
1.8.3.2