From a25d375917c5154237f18b2f83217133d0696919 Mon Sep 17 00:00:00 2001
From: md_5 <md_5@live.com.au>
Date: Thu, 7 Mar 2013 20:12:46 +1100
Subject: [PATCH] Async Operation Catching

Catch and throw an exception when a potentially unsafe operation occurs on a thread other than the main server thread.

diff --git a/src/main/java/net/minecraft/server/EntityTracker.java b/src/main/java/net/minecraft/server/EntityTracker.java
index 9e2b76f..d7efe3e 100644
--- a/src/main/java/net/minecraft/server/EntityTracker.java
+++ b/src/main/java/net/minecraft/server/EntityTracker.java
@@ -89,6 +89,7 @@ public class EntityTracker {
     }
 
     public void addEntity(Entity entity, int i, int j, boolean flag) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous entity track!"); // Spigot
         if (i > this.d) {
             i = this.d;
         }
@@ -124,6 +125,7 @@ public class EntityTracker {
     }
 
     public void untrackEntity(Entity entity) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous entity untrack!"); // Spigot
         if (entity instanceof EntityPlayer) {
             EntityPlayer entityplayer = (EntityPlayer) entity;
             Iterator iterator = this.b.iterator();
diff --git a/src/main/java/net/minecraft/server/EntityTrackerEntry.java b/src/main/java/net/minecraft/server/EntityTrackerEntry.java
index 5c03732..5f3c780 100644
--- a/src/main/java/net/minecraft/server/EntityTrackerEntry.java
+++ b/src/main/java/net/minecraft/server/EntityTrackerEntry.java
@@ -286,6 +286,7 @@ public class EntityTrackerEntry {
     }
 
     public void updatePlayer(EntityPlayer entityplayer) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous player tracker update!"); // Spigot
         if (entityplayer != this.tracker) {
             double d0 = entityplayer.locX - (double) (this.xLoc / 32);
             double d1 = entityplayer.locZ - (double) (this.zLoc / 32);
@@ -474,6 +475,7 @@ public class EntityTrackerEntry {
     }
 
     public void clear(EntityPlayer entityplayer) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous player tracker clear!"); // Spigot
         if (this.trackedPlayers.contains(entityplayer)) {
             this.trackedPlayers.remove(entityplayer);
             entityplayer.removeQueue.add(Integer.valueOf(this.tracker.id));
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index 964bef6..9306e57 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -924,6 +924,7 @@ public abstract class World implements IBlockAccess {
     }
 
     public boolean addEntity(Entity entity, SpawnReason spawnReason) { // Changed signature, added SpawnReason
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous entity add!"); // Spigot
         if (entity == null) return false;
         // CraftBukkit end
 
@@ -1030,6 +1031,7 @@ public abstract class World implements IBlockAccess {
     }
 
     public void removeEntity(Entity entity) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous entity remove!"); // Spigot
         entity.die();
         if (entity instanceof EntityHuman) {
             this.players.remove(entity);
@@ -2447,6 +2449,7 @@ public abstract class World implements IBlockAccess {
     }
 
     public void a(List list) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous entity world add!"); // Spigot
         // CraftBukkit start
         Entity entity = null;
         for (int i = 0; i < list.size(); ++i) {
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index d0e6d6f..d49393d 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -239,6 +239,7 @@ public class CraftWorld implements World {
     }
 
     public boolean unloadChunkRequest(int x, int z, boolean safe) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous chunk unload!"); // Spigot
         if (safe && isChunkInUse(x, z)) {
             return false;
         }
@@ -249,6 +250,7 @@ public class CraftWorld implements World {
     }
 
     public boolean unloadChunk(int x, int z, boolean save, boolean safe) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous chunk unload!"); // Spigot
         if (safe && isChunkInUse(x, z)) {
             return false;
         }
@@ -316,6 +318,7 @@ public class CraftWorld implements World {
     }
 
     public boolean loadChunk(int x, int z, boolean generate) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous chunk load!"); // Spigot
         chunkLoadCount++;
         if (generate) {
             // Use the default variant of loadChunk when generate == true.
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index df07a9b..7cae665 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -214,6 +214,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
     }
 
     public void kickPlayer(String message) {
+        if (Thread.currentThread() != MinecraftServer.getServer().primaryThread) throw new IllegalStateException("Asynchronous player kick!"); // Spigot
         if (getHandle().playerConnection == null) return;
 
         getHandle().playerConnection.disconnect(message == null ? "" : message);
-- 
1.8.1.2