From 8efeb3fe25915ec4d65f1f5b858716dfe01ce5e9 Mon Sep 17 00:00:00 2001
From: AJ Ferguson <fergusonjva@gmail.com>
Date: Fri, 27 Dec 2019 03:03:12 -0900
Subject: [PATCH] Fix exception when removing all entities

---
 .../network/session/cache/EntityCache.java          | 11 ++++-------
 .../geysermc/connector/utils/DimensionUtils.java    | 13 ++++++-------
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/connector/src/main/java/org/geysermc/connector/network/session/cache/EntityCache.java b/connector/src/main/java/org/geysermc/connector/network/session/cache/EntityCache.java
index fd0bd7c5..a248327a 100644
--- a/connector/src/main/java/org/geysermc/connector/network/session/cache/EntityCache.java
+++ b/connector/src/main/java/org/geysermc/connector/network/session/cache/EntityCache.java
@@ -25,10 +25,7 @@
 
 package org.geysermc.connector.network.session.cache;
 
-import it.unimi.dsi.fastutil.longs.Long2LongMap;
-import it.unimi.dsi.fastutil.longs.Long2LongOpenHashMap;
-import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
-import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.longs.*;
 import lombok.Getter;
 import org.geysermc.connector.entity.Entity;
 import org.geysermc.connector.entity.PlayerEntity;
@@ -45,9 +42,9 @@ public class EntityCache {
     private GeyserSession session;
 
     @Getter
-    private Long2ObjectMap<Entity> entities = new Long2ObjectOpenHashMap<>();
-    private Long2LongMap entityIdTranslations = new Long2LongOpenHashMap();
-    private Map<UUID, PlayerEntity> playerEntities = new HashMap<>();
+    private Long2ObjectMap<Entity> entities = Long2ObjectMaps.synchronize(new Long2ObjectOpenHashMap<>());
+    private Long2LongMap entityIdTranslations = Long2LongMaps.synchronize(new Long2LongOpenHashMap());
+    private Map<UUID, PlayerEntity> playerEntities = Collections.synchronizedMap(new HashMap<>());
     private Map<UUID, Long> bossbars = new HashMap<>();
 
     @Getter
diff --git a/connector/src/main/java/org/geysermc/connector/utils/DimensionUtils.java b/connector/src/main/java/org/geysermc/connector/utils/DimensionUtils.java
index 2f559da3..97053271 100644
--- a/connector/src/main/java/org/geysermc/connector/utils/DimensionUtils.java
+++ b/connector/src/main/java/org/geysermc/connector/utils/DimensionUtils.java
@@ -6,6 +6,9 @@ import org.geysermc.connector.entity.Entity;
 import org.geysermc.connector.network.session.GeyserSession;
 import org.geysermc.connector.network.translators.TranslatorsInit;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class DimensionUtils {
     public static void switchDimension(GeyserSession session, int javaDimension, boolean fake) {
         int bedrockDimension = javaToBedrock(javaDimension);
@@ -15,13 +18,9 @@ public class DimensionUtils {
 
         Vector3i pos = Vector3i.from(0, 32767, 0);
 
-        //FIXME: chance of exception while iterating
-        try {
-            for (Entity entity : session.getEntityCache().getEntities().values()) {
-                session.getEntityCache().removeEntity(entity, false);
-            }
-        } catch (Exception e) {
-            e.printStackTrace();
+        List<Entity> entities = new ArrayList<>(session.getEntityCache().getEntities().values());
+        for (Entity entity : entities) {
+            session.getEntityCache().removeEntity(entity, false);
         }
 
         ChangeDimensionPacket changeDimensionPacket = new ChangeDimensionPacket();