From 0000000000000000000000000000000000000000 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/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index 41e7474588d8e5ba4cd4af0fed1e62e452389a3e..20f73254881e0ed2957329245acef58c99e93fcb 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -731,6 +731,8 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
         // Spigot start
         // Iterator iterator = this.blockEntityTickers.iterator();
         int tilesThisCycle = 0;
+        var toRemove = new it.unimi.dsi.fastutil.objects.ObjectOpenCustomHashSet<TickingBlockEntity>(net.minecraft.Util.identityStrategy()); // Paper - use removeAll
+        toRemove.add(null);
         for (tileTickPosition = 0; tileTickPosition < this.blockEntityTickers.size(); tileTickPosition++) { // Paper - Disable tick limiters
             this.tileTickPosition = (this.tileTickPosition < this.blockEntityTickers.size()) ? this.tileTickPosition : 0;
             TickingBlockEntity tickingblockentity = (TickingBlockEntity) this.blockEntityTickers.get(tileTickPosition);
@@ -738,7 +740,6 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
             if (tickingblockentity == null) {
                 this.getCraftServer().getLogger().severe("Spigot has detected a null entity and has removed it, preventing a crash");
                 tilesThisCycle--;
-                this.blockEntityTickers.remove(this.tileTickPosition--);
                 continue;
             }
             // Spigot end
@@ -746,12 +747,13 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
             if (tickingblockentity.isRemoved()) {
                 // Spigot start
                 tilesThisCycle--;
-                this.blockEntityTickers.remove(this.tileTickPosition--);
+                toRemove.add(tickingblockentity); // Paper - use removeAll
                 // Spigot end
             } else if (this.shouldTickBlocksAt(ChunkPos.asLong(tickingblockentity.getPos()))) {
                 tickingblockentity.tick();
             }
         }
+        this.blockEntityTickers.removeAll(toRemove);
 
         timings.tileEntityTick.stopTiming(); // Spigot
         this.tickingBlockEntities = false;