Configurable chat thread limit (#7878)

patches/server/Configurable-chat-thread-limit.patch

@@ -0,0 +1,55 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Shane Freeder <theboyetronic@gmail.com>
+Date: Sun, 18 Sep 2022 06:33:17 +0100
+Subject: [PATCH] Configurable chat thread limit
+
+By default, spigot shifts chat over to an unbounded thread pool,
+on a normal server, this really offers no gains, the creation of a thread
+on submitting to the pool on these servers eats more time vs just running it in
+the netty pipeline, however, on servers using plugins which do work in here, there
+could be some overall benefits to moving this stuff outside of the pipeline.
+
+In general, this patch does two things:
+1) Exposes the core size for the pool, this allows for ensuring that a number of threads
+sit around in the pool, mitigating the need for creating new threads; This IS however
+caveated, the ThreadPoolExecutor will ONLY create core threads as they're needed, it
+just won't allow for us to dip back under the # of core threads, this can potentially
+be mitigated by calling prestartCoreThread, however, I'm not sure if there is much justification
+for this
+2) Exposes a max size for the pool, as stated, by default this is unbounded, for most
+servers limiting the size of the pool is going to have 0 effects given how fast chat
+is actually processed, this is honestly really just exposed for the misnomers or people
+who just wanna ensure that this won't grow over a specific size if chat gets stupidly active
+
+diff --git a/src/main/java/io/papermc/paper/configuration/GlobalConfiguration.java b/src/main/java/io/papermc/paper/configuration/GlobalConfiguration.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/io/papermc/paper/configuration/GlobalConfiguration.java
++++ b/src/main/java/io/papermc/paper/configuration/GlobalConfiguration.java
+@@ -0,0 +0,0 @@ public class GlobalConfiguration extends ConfigurationPart {
+     public Misc misc;
+ 
+     public class Misc extends ConfigurationPart {
++
++        public ChatThreads chatThreads;
+         public class ChatThreads extends ConfigurationPart.Post {
+             private int chatExecutorCoreSize = -1;
+             private int chatExecutorMaxSize = -1;
+ 
+             @Override
+             public void postProcess() {
+-                // TODO: FILL
++                //noinspection ConstantConditions
++                if (net.minecraft.server.MinecraftServer.getServer() == null) return; // In testing env, this will be null here
++                int _chatExecutorMaxSize = (chatExecutorMaxSize <= 0) ? Integer.MAX_VALUE : chatExecutorMaxSize; // This is somewhat dumb, but, this is the default, do we cap this?;
++                int _chatExecutorCoreSize = Math.max(chatExecutorCoreSize, 0);
++
++                if (_chatExecutorMaxSize < _chatExecutorCoreSize) {
++                    _chatExecutorMaxSize = _chatExecutorCoreSize;
++                }
++
++                java.util.concurrent.ThreadPoolExecutor executor = (java.util.concurrent.ThreadPoolExecutor) net.minecraft.server.MinecraftServer.getServer().chatExecutor;
++                executor.setCorePoolSize(_chatExecutorCoreSize);
++                executor.setMaximumPoolSize(_chatExecutorMaxSize);
+             }
+         }
+         public int maxJoinsPerTick = 3;

patches/server/Paper-config-files.patch

@@ -688,6 +688,15 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +    public Misc misc;
 +
 +    public class Misc extends ConfigurationPart {
++        public class ChatThreads extends ConfigurationPart.Post {
++            private int chatExecutorCoreSize = -1;
++            private int chatExecutorMaxSize = -1;
++
++            @Override
++            public void postProcess() {
++                // TODO: FILL
++            }
++        }
 +        public int maxJoinsPerTick = 3;
 +        public boolean fixEntityPositionDesync = true;
 +        public boolean loadPermissionsYmlBeforePlugins = true;