Paper/Spigot-Server-Patches/0172-Fix-MC-117075-TE-Unload-Lag-Spike.patch
Spottedleaf 994679a0c9 Fix patch "Faster redstone torch rapid clock removal" (#2014)
Tux pointed out the patch still has O(n^2) time complexity since
the sublist class in arraylist does not override clear() from
AbstractList, which uses a forward moving iterator to clear
the list.

Resolved by using a peek and poll from ArrayDeque.

This patch also removes the useless WeakHashMap which holds
the list (it mapped world->list) and replaces it with a
field on World.
2019-05-10 16:48:58 +01:00

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1.3 KiB
Diff

From 4a06cdf0e8a73013b84c46cd67d12b3cec8cbfb4 Mon Sep 17 00:00:00 2001
From: mezz <tehgeek@gmail.com>
Date: Wed, 9 Aug 2017 17:51:22 -0500
Subject: [PATCH] Fix MC-117075: TE Unload Lag Spike
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 8ac081bef..f9413dd68 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -730,7 +730,11 @@ public abstract class World implements IIBlockAccess, GeneratorAccess, AutoClose
gameprofilerfiller.enter("blockEntities");
timings.tileEntityTick.startTiming(); // Spigot
if (!this.tileEntityListUnload.isEmpty()) {
- this.tileEntityListTick.removeAll(this.tileEntityListUnload);
+ // Paper start - Use alternate implementation with faster contains
+ java.util.Set<TileEntity> toRemove = java.util.Collections.newSetFromMap(new java.util.IdentityHashMap<>());
+ toRemove.addAll(tileEntityListUnload);
+ this.tileEntityListTick.removeAll(toRemove);
+ // Paper end
//this.tileEntityList.removeAll(this.tileEntityListUnload); // Paper - remove unused list
this.tileEntityListUnload.clear();
}
--
2.21.0