From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Samsuik <kfian294ma4@gmail.com>
Date: Fri, 13 Sep 2024 17:22:51 +0100
Subject: [PATCH] Tick entity schedulers only when necessary


diff --git a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/server/ServerEntityLookup.java b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/server/ServerEntityLookup.java
index 58d9187adc188b693b6becc400f766e069bf1bf5..8b7860390717c3d2a3c0f3d2b081799bcd3d65c1 100644
--- a/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/server/ServerEntityLookup.java
+++ b/src/main/java/ca/spottedleaf/moonrise/patches/chunk_system/level/entity/server/ServerEntityLookup.java
@@ -19,6 +19,22 @@ public final class ServerEntityLookup extends EntityLookup {
 
     private final ServerLevel serverWorld;
     public final ReferenceList<Entity> trackerEntities = new ReferenceList<>(EMPTY_ENTITY_ARRAY); // Moonrise - entity tracker
+    // Sakura start - tick entity schedulers only when necessary
+    public final ReferenceList<org.bukkit.craftbukkit.entity.CraftEntity> scheduledEntities = new ReferenceList<>();
+
+    public void entityStartScheduled(final Entity entity) {
+        org.bukkit.craftbukkit.entity.CraftEntity bukkitEntity = entity.getBukkitEntityRaw();
+        if (bukkitEntity != null && bukkitEntity.taskScheduler.hasTask()) {
+            this.scheduledEntities.add(bukkitEntity);
+        }
+    }
+
+    public void entityEndScheduled(final Entity entity) {
+        if (entity.getBukkitEntityRaw() != null) {
+            this.scheduledEntities.remove(entity.getBukkitEntityRaw());
+        }
+    }
+    // Sakura end - tick entity schedulers only when necessary
 
     public ServerEntityLookup(final ServerLevel world, final LevelCallback<Entity> worldCallback) {
         super(world, worldCallback);
@@ -90,6 +106,7 @@ public final class ServerEntityLookup extends EntityLookup {
         // Moonrise start - entity tracker
         this.trackerEntities.add(entity);
         // Moonrise end - entity tracker
+        this.entityStartScheduled(entity); // Sakura - tick entity schedulers only when necessary
     }
 
     @Override
@@ -97,6 +114,7 @@ public final class ServerEntityLookup extends EntityLookup {
         // Moonrise start - entity tracker
         this.trackerEntities.remove(entity);
         // Moonrise end - entity tracker
+        this.entityEndScheduled(entity); // Sakura - tick entity schedulers only when necessary
     }
 
     @Override
diff --git a/src/main/java/io/papermc/paper/threadedregions/EntityScheduler.java b/src/main/java/io/papermc/paper/threadedregions/EntityScheduler.java
index c03608fec96b51e1867f43d8f42e5aefb1520e46..32ac34e6ca4a7443e894369fee349911ebc1cf52 100644
--- a/src/main/java/io/papermc/paper/threadedregions/EntityScheduler.java
+++ b/src/main/java/io/papermc/paper/threadedregions/EntityScheduler.java
@@ -50,6 +50,22 @@ public final class EntityScheduler {
         this.entity = Validate.notNull(entity);
     }
 
+    // Sakura start - tick entity schedulers only when necessary
+    public boolean hasTask() {
+        return !this.currentlyExecuting.isEmpty() || !this.oneTimeDelayed.isEmpty();
+    }
+
+    private void newScheduledTask() {
+        net.minecraft.server.MinecraftServer.getServer().scheduleOnMain(() -> {
+            Entity handle = this.entity.getHandleRaw();
+            net.minecraft.server.level.ServerLevel level = (net.minecraft.server.level.ServerLevel) handle.level();
+            ca.spottedleaf.moonrise.patches.chunk_system.level.entity.server.ServerEntityLookup entityLookup = (ca.spottedleaf.moonrise.patches.chunk_system.level.entity.server.ServerEntityLookup) level.moonrise$getEntityLookup();
+
+            entityLookup.entityStartScheduled(handle);
+        });
+    }
+    // Sakura end - tick entity schedulers only when necessary
+
     /**
      * Retires the scheduler, preventing new tasks from being scheduled and invoking the retired callback
      * on all currently scheduled tasks.
@@ -128,6 +144,7 @@ public final class EntityScheduler {
                 return new ArrayList<>();
             }).add(task);
         }
+        this.newScheduledTask(); // Sakura - tick entity schedulers only when necessary
 
         return true;
     }
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 56357e253247d19c108a7f753058fa3eba0302ee..c2c0cd8ae1afd90d9b08adec3cb127b13ce60331 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -1824,7 +1824,17 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
         // Paper start - Folia scheduler API
         ((io.papermc.paper.threadedregions.scheduler.FoliaGlobalRegionScheduler) Bukkit.getGlobalRegionScheduler()).tick();
         getAllLevels().forEach(level -> {
-            for (final Entity entity : level.getEntities().getAll()) {
+            // Sakura start - tick entity schedulers only when necessary
+            final ca.spottedleaf.moonrise.patches.chunk_system.level.entity.server.ServerEntityLookup entityLookup = (ca.spottedleaf.moonrise.patches.chunk_system.level.entity.server.ServerEntityLookup) level.moonrise$getEntityLookup();
+            final Iterator<org.bukkit.craftbukkit.entity.CraftEntity> entityIterator = entityLookup.scheduledEntities.iterator();
+            while (entityIterator.hasNext()) {
+                final org.bukkit.craftbukkit.entity.CraftEntity scheduledEntity = entityIterator.next();
+                final Entity entity = scheduledEntity.getHandle();
+                if (!scheduledEntity.taskScheduler.hasTask()) {
+                    entityIterator.remove();
+                    continue;
+                }
+                // Sakura end - tick entity schedulers only when necessary
                 if (entity.isRemoved()) {
                     continue;
                 }