From b739b47db7bd4f5083b98e6168f265f53c272411 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 8 Apr 2020 21:24:05 -0400
Subject: [PATCH] Increase Light Queue Size

Wiz mentioned that large WorldEdit operations cause light to run on
main thread. The queue was small, set to 5.. this bumps it to 20
but makes it configurable per-world.

The main risk of increasing this higher is during shutdown, some
queued light updates may be lost because mojang did not flush the
light engine on shutdown...

The queue size only puts a cap on max loss, doesn't solve that problem.

diff --git a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
index 659a011e97..88a45e517c 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -684,4 +684,9 @@ public class PaperWorldConfig {
     private void trackerUpdateDistance() {
         trackerUpdateDistance = getDouble("tracker-update-distance", trackerUpdateDistance);
     }
+
+    public int lightQueueSize = 20;
+    private void lightQueueSize() {
+        lightQueueSize = getInt("light-queue-size", lightQueueSize);
+    }
 }
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index d1f82eff21..77adc64e30 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -637,7 +637,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
         this.executeModerately();
         // CraftBukkit end
         worldloadlistener.b();
-        chunkproviderserver.getLightEngine().a(5);
+        chunkproviderserver.getLightEngine().a(worldserver.paperConfig.lightQueueSize); // Paper - increase light queue size
 
         // CraftBukkit start
         this.forceTicks = false;
-- 
2.26.2