From 97ff8b2304836754dc4178e714f3484009a01288 Mon Sep 17 00:00:00 2001
From: md_5 <git@md-5.net>
Date: Tue, 25 Mar 2014 16:10:01 +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/level/ChunkMapDistance.java b/src/main/java/net/minecraft/server/level/ChunkMapDistance.java
index faff79f8f..2e44b6852 100644
--- a/src/main/java/net/minecraft/server/level/ChunkMapDistance.java
+++ b/src/main/java/net/minecraft/server/level/ChunkMapDistance.java
@@ -102,6 +102,7 @@ public abstract class ChunkMapDistance {
     protected abstract PlayerChunk updateChunkScheduling(long i, int j, @Nullable PlayerChunk playerchunk, int k);
 
     public boolean runAllUpdates(PlayerChunkMap playerchunkmap) {
+        org.spigotmc.AsyncCatcher.catchOp("chunk updates"); // Spigot
         this.naturalSpawnChunkCounter.runAllUpdates();
         this.tickingTicketsTracker.runAllUpdates();
         this.playerTicketManager.runAllUpdates();
diff --git a/src/main/java/net/minecraft/server/level/PlayerChunkMap.java b/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
index 4d8aa931f..5043631d1 100644
--- a/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
+++ b/src/main/java/net/minecraft/server/level/PlayerChunkMap.java
@@ -1249,6 +1249,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.b, Gener
     }
 
     protected void addEntity(Entity entity) {
+        org.spigotmc.AsyncCatcher.catchOp("entity track"); // Spigot
         if (!(entity instanceof EntityComplexPart)) {
             EntityTypes<?> entitytypes = entity.getType();
             int i = entitytypes.clientTrackingRange() * 16;
@@ -1284,6 +1285,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.b, Gener
     }
 
     protected void removeEntity(Entity entity) {
+        org.spigotmc.AsyncCatcher.catchOp("entity untrack"); // Spigot
         if (entity instanceof EntityPlayer entityplayer) {
             this.updatePlayerStatus(entityplayer, false);
             ObjectIterator objectiterator = this.entityMap.values().iterator();
@@ -1503,6 +1505,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.b, Gener
         }
 
         public void removePlayer(EntityPlayer entityplayer) {
+            org.spigotmc.AsyncCatcher.catchOp("player tracker clear"); // Spigot
             if (this.seenBy.remove(entityplayer.connection)) {
                 this.serverEntity.removePairing(entityplayer);
             }
@@ -1510,6 +1513,7 @@ public class PlayerChunkMap extends IChunkLoader implements PlayerChunk.b, Gener
         }
 
         public void updatePlayer(EntityPlayer entityplayer) {
+            org.spigotmc.AsyncCatcher.catchOp("player tracker update"); // Spigot
             if (entityplayer != this.entity) {
                 Vec3D vec3d = entityplayer.position().subtract(this.entity.position());
                 int i = PlayerChunkMap.this.getPlayerViewDistance(entityplayer);
diff --git a/src/main/java/net/minecraft/server/level/WorldServer.java b/src/main/java/net/minecraft/server/level/WorldServer.java
index ba487c2ac..ad8a7fff1 100644
--- a/src/main/java/net/minecraft/server/level/WorldServer.java
+++ b/src/main/java/net/minecraft/server/level/WorldServer.java
@@ -1068,6 +1068,7 @@ public class WorldServer extends World implements ServerEntityGetter, GeneratorA
 
     // CraftBukkit start
     private boolean addEntity(Entity entity, CreatureSpawnEvent.SpawnReason spawnReason) {
+        org.spigotmc.AsyncCatcher.catchOp("entity add"); // Spigot
         if (entity.isRemoved()) {
             // WorldServer.LOGGER.warn("Tried to add entity {} but it was marked as removed already", EntityTypes.getKey(entity.getType())); // CraftBukkit
             return false;
@@ -1936,6 +1937,7 @@ public class WorldServer extends World implements ServerEntityGetter, GeneratorA
 
     @Override
     public LevelEntityGetter<Entity> getEntities() {
+        org.spigotmc.AsyncCatcher.catchOp("Chunk getEntities call"); // Spigot
         return this.entityManager.getEntityGetter();
     }
 
@@ -2055,6 +2057,7 @@ public class WorldServer extends World implements ServerEntityGetter, GeneratorA
         }
 
         public void onTrackingStart(Entity entity) {
+            org.spigotmc.AsyncCatcher.catchOp("entity register"); // Spigot
             WorldServer.this.getChunkSource().addEntity(entity);
             if (entity instanceof EntityPlayer entityplayer) {
                 WorldServer.this.players.add(entityplayer);
@@ -2088,6 +2091,7 @@ public class WorldServer extends World implements ServerEntityGetter, GeneratorA
         }
 
         public void onTrackingEnd(Entity entity) {
+            org.spigotmc.AsyncCatcher.catchOp("entity unregister"); // Spigot
             WorldServer.this.getChunkSource().removeEntity(entity);
             if (entity instanceof EntityPlayer entityplayer) {
                 WorldServer.this.players.remove(entityplayer);
diff --git a/src/main/java/net/minecraft/world/entity/EntityLiving.java b/src/main/java/net/minecraft/world/entity/EntityLiving.java
index 510378852..86f232121 100644
--- a/src/main/java/net/minecraft/world/entity/EntityLiving.java
+++ b/src/main/java/net/minecraft/world/entity/EntityLiving.java
@@ -1129,6 +1129,7 @@ public abstract class EntityLiving extends Entity implements Attackable {
     }
 
     public boolean addEffect(MobEffect mobeffect, @Nullable Entity entity, EntityPotionEffectEvent.Cause cause) {
+        org.spigotmc.AsyncCatcher.catchOp("effect add"); // Spigot
         if (isTickingEffects) {
             effectsToProcess.add(new ProcessableEffect(mobeffect, cause));
             return true;
diff --git a/src/main/java/net/minecraft/world/item/crafting/CraftingManager.java b/src/main/java/net/minecraft/world/item/crafting/CraftingManager.java
index eaf464384..489aefe4a 100644
--- a/src/main/java/net/minecraft/world/item/crafting/CraftingManager.java
+++ b/src/main/java/net/minecraft/world/item/crafting/CraftingManager.java
@@ -118,6 +118,7 @@ public class CraftingManager extends ResourceDataAbstract<RecipeMap> implements
 
     // CraftBukkit start
     public void addRecipe(RecipeHolder<?> irecipe) {
+        org.spigotmc.AsyncCatcher.catchOp("Recipe Add"); // Spigot
         this.recipes.addRecipe(irecipe);
         finalizeRecipeLoading();
     }
diff --git a/src/main/java/net/minecraft/world/level/block/state/BlockBase.java b/src/main/java/net/minecraft/world/level/block/state/BlockBase.java
index d60d8b93f..102121490 100644
--- a/src/main/java/net/minecraft/world/level/block/state/BlockBase.java
+++ b/src/main/java/net/minecraft/world/level/block/state/BlockBase.java
@@ -161,7 +161,9 @@ public abstract class BlockBase implements FeatureElement {
 
     protected void neighborChanged(IBlockData iblockdata, World world, BlockPosition blockposition, Block block, @Nullable Orientation orientation, boolean flag) {}
 
-    protected void onPlace(IBlockData iblockdata, World world, BlockPosition blockposition, IBlockData iblockdata1, boolean flag) {}
+    protected void onPlace(IBlockData iblockdata, World world, BlockPosition blockposition, IBlockData iblockdata1, boolean flag) {
+        org.spigotmc.AsyncCatcher.catchOp("block onPlace"); // Spigot
+    }
 
     // CraftBukkit start
     protected void onPlace(IBlockData iblockdata, World world, BlockPosition blockposition, IBlockData iblockdata1, boolean flag, @Nullable ItemActionContext context) {
@@ -170,6 +172,7 @@ public abstract class BlockBase implements FeatureElement {
     // CraftBukkit end
 
     protected void onRemove(IBlockData iblockdata, World world, BlockPosition blockposition, IBlockData iblockdata1, boolean flag) {
+        org.spigotmc.AsyncCatcher.catchOp("block remove"); // Spigot
         if (iblockdata.hasBlockEntity() && !iblockdata.is(iblockdata1.getBlock())) {
             world.removeBlockEntity(blockposition);
         }
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index 71cb0d98b..862f5d3ec 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -900,6 +900,7 @@ public final class CraftServer implements Server {
     public boolean dispatchCommand(CommandSender sender, String commandLine) {
         Preconditions.checkArgument(sender != null, "sender cannot be null");
         Preconditions.checkArgument(commandLine != null, "commandLine cannot be null");
+        org.spigotmc.AsyncCatcher.catchOp("command dispatch"); // Spigot
 
         if (commandMap.dispatch(sender, commandLine)) {
             return true;
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index b689d7d20..3aad490b1 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -288,6 +288,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public boolean unloadChunkRequest(int x, int z) {
+        org.spigotmc.AsyncCatcher.catchOp("chunk unload"); // Spigot
         if (isChunkLoaded(x, z)) {
             world.getChunkSource().removeRegionTicket(TicketType.PLUGIN, new ChunkCoordIntPair(x, z), 1, Unit.INSTANCE);
         }
@@ -296,6 +297,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
     }
 
     private boolean unloadChunk0(int x, int z, boolean save) {
+        org.spigotmc.AsyncCatcher.catchOp("chunk unload"); // Spigot
         if (!isChunkLoaded(x, z)) {
             return true;
         }
@@ -312,6 +314,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public boolean regenerateChunk(int x, int z) {
+        org.spigotmc.AsyncCatcher.catchOp("chunk regenerate"); // Spigot
         throw new UnsupportedOperationException("Not supported in this Minecraft version! Unless you can fix it, this is not a bug :)");
         /*
         if (!unloadChunk0(x, z, false)) {
@@ -389,6 +392,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public boolean loadChunk(int x, int z, boolean generate) {
+        org.spigotmc.AsyncCatcher.catchOp("chunk load"); // Spigot
         IChunkAccess chunk = world.getChunkSource().getChunk(x, z, generate ? ChunkStatus.FULL : ChunkStatus.EMPTY, true);
 
         // If generate = false, but the chunk already exists, we will get this back.
@@ -924,6 +928,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public Collection<Entity> getNearbyEntities(BoundingBox boundingBox, Predicate<? super Entity> filter) {
+        org.spigotmc.AsyncCatcher.catchOp("getNearbyEntities"); // Spigot
         Preconditions.checkArgument(boundingBox != null, "BoundingBox cannot be null");
 
         AxisAlignedBB bb = new AxisAlignedBB(boundingBox.getMinX(), boundingBox.getMinY(), boundingBox.getMinZ(), boundingBox.getMaxX(), boundingBox.getMaxY(), boundingBox.getMaxZ());
@@ -1078,6 +1083,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
     @Override
     public void save() {
+        org.spigotmc.AsyncCatcher.catchOp("world save"); // Spigot
         this.server.checkSaveState();
         boolean oldSave = world.noSave;
 
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
index ff47b09dc..f9aba6e6d 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
@@ -230,6 +230,7 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
     @Override
     public List<org.bukkit.entity.Entity> getNearbyEntities(double x, double y, double z) {
         Preconditions.checkState(!entity.generation, "Cannot get nearby entities during world generation");
+        org.spigotmc.AsyncCatcher.catchOp("getNearbyEntities"); // Spigot
 
         List<Entity> notchEntityList = entity.level().getEntities(entity, entity.getBoundingBox().inflate(x, y, z), Predicates.alwaysTrue());
         List<org.bukkit.entity.Entity> bukkitEntityList = new java.util.ArrayList<org.bukkit.entity.Entity>(notchEntityList.size());
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index daf975fd0..7e49a4edf 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -496,6 +496,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
 
     @Override
     public void kickPlayer(String message) {
+        org.spigotmc.AsyncCatcher.catchOp("player kick"); // Spigot
         getHandle().transferCookieConnection.kickPlayer(CraftChatMessage.fromStringOrEmpty(message, true));
     }
 
diff --git a/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java b/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java
index 726887ece..ec5670e24 100644
--- a/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java
+++ b/src/main/java/org/bukkit/craftbukkit/scoreboard/CraftScoreboardManager.java
@@ -41,6 +41,7 @@ public final class CraftScoreboardManager implements ScoreboardManager {
 
     @Override
     public CraftScoreboard getNewScoreboard() {
+        org.spigotmc.AsyncCatcher.catchOp("scoreboard creation"); // Spigot
         CraftScoreboard scoreboard = new CraftScoreboard(new ScoreboardServer(server));
         scoreboards.add(scoreboard);
         return scoreboard;
diff --git a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
index 2e057fd4c..ddef523ea 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
@@ -12,6 +12,7 @@ public class ServerShutdownThread extends Thread {
     @Override
     public void run() {
         try {
+            org.spigotmc.AsyncCatcher.enabled = false; // Spigot
             server.close();
         } finally {
             try {
diff --git a/src/main/java/org/spigotmc/AsyncCatcher.java b/src/main/java/org/spigotmc/AsyncCatcher.java
new file mode 100644
index 000000000..aeed76972
--- /dev/null
+++ b/src/main/java/org/spigotmc/AsyncCatcher.java
@@ -0,0 +1,17 @@
+package org.spigotmc;
+
+import net.minecraft.server.MinecraftServer;
+
+public class AsyncCatcher
+{
+
+    public static boolean enabled = true;
+
+    public static void catchOp(String reason)
+    {
+        if ( enabled && Thread.currentThread() != MinecraftServer.getServer().serverThread )
+        {
+            throw new IllegalStateException( "Asynchronous " + reason + "!" );
+        }
+    }
+}
-- 
2.48.1