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 6c8e9d498c9a30a1aa88494ba09c3cae012a8fa1..cd248eb6be663e8be33f2c3c6b06b77b6d5753a4 100644
--- a/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
+++ b/src/main/java/com/destroystokyo/paper/PaperWorldConfig.java
@@ -620,4 +620,9 @@ 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 f625ed0ac4a1740c2b0fdf2a7e6b92fdcfdb1dce..0f38b3acb8d40bc4753275045db5861945865b35 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -657,7 +657,7 @@ 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.updateSpawnFlags();
         worldserver.setSpawnFlags(this.getSpawnMonsters(), this.getSpawnAnimals());