0014-Disable-Explicit-Network-Manager-Flushing.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Fri, 29 Oct 2021 05:24:16 -0400
Subject: [PATCH] Disable Explicit Network Manager Flushing

This seems completely pointless, as packet dispatch uses .writeAndFlush.

Things seem to work fine without explicit flushing, but incase issues arise,
provide a System property to re-enable it using improved logic of doing the
flushing on the netty event loop, so it won't do the flush on the main thread.

Renable flushing by passing -Dpaper.explicit-flush=true

diff --git a/src/main/java/net/minecraft/server/NetworkManager.java b/src/main/java/net/minecraft/server/NetworkManager.java
index ae7c6e289c8a6d9f8bdd4911e90e2ef9840069a2..d547fe7b3a1e2355043a82cec9d40b69b2e410b0 100644
--- a/src/main/java/net/minecraft/server/NetworkManager.java
+++ b/src/main/java/net/minecraft/server/NetworkManager.java
@@ -74,6 +74,7 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet> {
     private IChatBaseComponent n;
     private boolean o;
     private boolean p;
+    private static boolean enableExplicitFlush = Boolean.getBoolean("paper.explicit-flush"); // PandaSpigot - Disable explicit flushing
     // PandaSpigot start - Optimize network
     public boolean isPending = true;
     public boolean queueImmunity = false;
@@ -406,7 +407,7 @@ public class NetworkManager extends SimpleChannelInboundHandler<Packet> {
             ((IUpdatePlayerListBox) this.m).c();
         }
 
-        this.channel.flush();
+        if (enableExplicitFlush) this.channel.eventLoop().execute(() -> this.channel.flush()); // PandaSpigot - we don't need to explicit flush here, but allow opt-in in case issues are found to a better version
     }
 
     public SocketAddress getSocketAddress() {