From 0000000000000000000000000000000000000000 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 29eaa572648113216a267462a79da7e3741d1cfe..51d30a92cbc1052b690b5565e403123c39f864da 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -608,4 +608,9 @@ public class PaperWorldConfig {
     private void zombieVillagerInfectionChance() {
         zombieVillagerInfectionChance = getDouble("zombie-villager-infection-chance", zombieVillagerInfectionChance);
     }
+
+    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 60b018fb6865a4b73f944cffd79e7d246636360b..c97e8235b323b7ed69dda891fd73ea655c1e16f5 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -660,7 +660,7 @@ 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
         this.bc();
 
         // CraftBukkit start