From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: NONPLAYT <76615486+NONPLAYT@users.noreply.github.com>
Date: Sat, 1 Mar 2025 23:06:52 +0300
Subject: [PATCH] Petal: Multithreaded Tracker

Original project: https://github.com/Bloom-host/Petal
Original license: GPL v3

Patch description:

We made much of tracking logic asynchronously, and fixed visible issue
for the case of some NPC plugins which using real entity type, e.g. Citizens.

But it is still recommending to use those packet based, virtual entity
based NPC plugins, e.g. ZNPC Plus, Adyeshach, Fancy NPC, etc.

diff --git a/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java b/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
index d7398b1ecf2660c29fb7d106b48fe02d3736603e..ab499a7eaccdc1578ec64f90f54f79b0da3c0e96 100644
--- a/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
+++ b/src/main/java/io/papermc/paper/plugin/manager/PaperEventManager.java
@@ -42,6 +42,12 @@ class PaperEventManager {
         if (event.isAsynchronous() && this.server.isPrimaryThread()) {
             throw new IllegalStateException(event.getEventName() + " may only be triggered asynchronously.");
         } else if (!event.isAsynchronous() && !this.server.isPrimaryThread() && !this.server.isStopping()) {
+            // DivineMC start - Multithreaded Tracker
+            if (org.bxteam.divinemc.config.DivineConfig.AsyncCategory.multithreadedEnabled) {
+                net.minecraft.server.MinecraftServer.getServer().scheduleOnMain(event::callEvent);
+                return;
+            }
+            // DivineMC end - Multithreaded Tracker
             throw new IllegalStateException(event.getEventName() + " may only be triggered synchronously.");
         }
 
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
index 6b8841a1a84f6316b89b052328bbb549b4acbe21..56aac091b6c126132d75835af340fae40e3a03f0 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
@@ -2825,7 +2825,7 @@ public class CraftPlayer extends CraftHumanEntity implements Player, PluginMessa
         Iterator<AttributeInstance> iterator = collection.iterator();
         while (iterator.hasNext()) {
             AttributeInstance genericInstance = iterator.next();
-            if (genericInstance.getAttribute() == Attributes.MAX_HEALTH) {
+            if (genericInstance != null && genericInstance.getAttribute() == Attributes.MAX_HEALTH) {
                 iterator.remove();
                 break;
             }
diff --git a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
index 9baeecc248fe9ee6d7bb6c63d6b390b048a5649c..3a36b1c3602292a0264cfbe02b9659878fd7a217 100644
--- a/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
+++ b/src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
@@ -1803,6 +1803,26 @@ public class CraftEventFactory {
     }
 
     public static boolean handleBlockFormEvent(Level world, BlockPos pos, net.minecraft.world.level.block.state.BlockState state, int flags, @Nullable Entity entity, boolean checkSetResult) {
+        // DivineMC start - Multithreaded Tracker
+        if (org.bxteam.divinemc.config.DivineConfig.AsyncCategory.multithreadedEnabled && Thread.currentThread() instanceof org.bxteam.divinemc.async.tracking.MultithreadedTracker.MultithreadedTrackerThread) {
+            java.util.concurrent.CompletableFuture<Boolean> future = new java.util.concurrent.CompletableFuture<>();
+            net.minecraft.server.MinecraftServer.getServer().scheduleOnMain(() -> {
+                boolean resultFlag = false;
+                CraftBlockState snapshot = CraftBlockStates.getBlockState(world, pos);
+                snapshot.setData(state);
+
+                BlockFormEvent event = (entity == null) ? new BlockFormEvent(snapshot.getBlock(), snapshot) : new EntityBlockFormEvent(entity.getBukkitEntity(), snapshot.getBlock(), snapshot);
+                if (event.callEvent()) {
+                    boolean result = snapshot.place(flags);
+                    resultFlag = !checkSetResult || result;
+                }
+
+                future.complete(resultFlag);
+            });
+
+            return future.join();
+        }
+        // DivineMC end - Multithreaded Tracker
         CraftBlockState snapshot = CraftBlockStates.getBlockState(world, pos);
         snapshot.setData(state);