Leaf/leaf-server/paper-patches/features/0033-SparklyPaper-Skip-EntityScheduler-s-executeTick-chec.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: MrPowerGamerBR <git@mrpowergamerbr.com>
Date: Sun, 19 Nov 2023 12:35:16 -0300
Subject: [PATCH] SparklyPaper: Skip EntityScheduler's executeTick checks if
 there isn't any tasks to be run

Original project: https://github.com/SparklyPower/SparklyPaper

On each tick, Paper runs EntityScheduler's executeTick of each entity. This is a bit expensive, due to ArrayDeque's size() call because it ain't a simple "get the current queue size" function, due to the thread checks, and because it needs to iterate all entities in all worlds.

To avoid the hefty ArrayDeque's size() call, we check if we *really* need to execute the executeTick, by adding all entities with scheduled tasks to a global set.

Most entities won't have any scheduled tasks, so this is a nice performance bonus. These optimizations, however, wouldn't work in a Folia environment, but because in SparklyPaper executeTick is always executed on the main thread, it ain't an issue for us (yay).

diff --git a/src/main/java/io/papermc/paper/threadedregions/EntityScheduler.java b/src/main/java/io/papermc/paper/threadedregions/EntityScheduler.java
index c03608fec96b51e1867f43d8f42e5aefb1520e46..56268cf8d184e0b6cd46de8c2e893ad3da8ec64f 100644
--- a/src/main/java/io/papermc/paper/threadedregions/EntityScheduler.java
+++ b/src/main/java/io/papermc/paper/threadedregions/EntityScheduler.java
@@ -36,6 +36,7 @@ public final class EntityScheduler {
      * The Entity. Note that it is the CraftEntity, since only that class properly tracks world transfers.
      */
     public final CraftEntity entity;
+    public final net.minecraft.server.MinecraftServer server; // SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
 
     private static final record ScheduledTask(Consumer<? extends Entity> run, Consumer<? extends Entity> retired) {}
 
@@ -46,7 +47,8 @@ public final class EntityScheduler {
 
     private final ArrayDeque<ScheduledTask> currentlyExecuting = new ArrayDeque<>();
 
-    public EntityScheduler(final CraftEntity entity) {
+    public EntityScheduler(final net.minecraft.server.MinecraftServer server, final CraftEntity entity) { // SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
+        this.server = Validate.notNull(server);
         this.entity = Validate.notNull(entity);
     }
 
@@ -61,14 +63,16 @@ public final class EntityScheduler {
      * @throws IllegalStateException If the scheduler is already retired.
      */
     public void retire() {
+        final Entity thisEntity = this.entity.getHandleRaw(); // SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
         synchronized (this.stateLock) {
             if (this.tickCount == RETIRED_TICK_COUNT) {
                 throw new IllegalStateException("Already retired");
             }
             this.tickCount = RETIRED_TICK_COUNT;
+            this.server.entitiesWithScheduledTasks.remove(thisEntity); // SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
         }
 
-        final Entity thisEntity = this.entity.getHandleRaw();
+        //final Entity thisEntity = this.entity.getHandleRaw(); // SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run (moved up)
 
         // correctly handle and order retiring while running executeTick
         for (int i = 0, len = this.currentlyExecuting.size(); i < len; ++i) {
@@ -124,6 +128,7 @@ public final class EntityScheduler {
             if (this.tickCount == RETIRED_TICK_COUNT) {
                 return false;
             }
+            this.server.entitiesWithScheduledTasks.add(this.entity.getHandleRaw()); // SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
             this.oneTimeDelayed.computeIfAbsent(this.tickCount + Math.max(1L, delay), (final long keyInMap) -> {
                 return new ArrayList<>();
             }).add(task);
@@ -143,6 +148,13 @@ public final class EntityScheduler {
         TickThread.ensureTickThread(thisEntity, "May not tick entity scheduler asynchronously");
         final List<ScheduledTask> toRun;
         synchronized (this.stateLock) {
+            // SparklyPaper start - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
+            // Do we *really* have scheduled tasks tho?
+            if (this.currentlyExecuting.isEmpty() && this.oneTimeDelayed.isEmpty()) { // Check if we have any pending tasks and, if not, skip!
+                this.server.entitiesWithScheduledTasks.remove(thisEntity); // We don't! Bye bye!!
+                return;
+            }
+            // SparklyPaper end
             if (this.tickCount == RETIRED_TICK_COUNT) {
                 throw new IllegalStateException("Ticking retired scheduler");
             }
@@ -178,4 +190,12 @@ public final class EntityScheduler {
             }
         }
     }
+
+    // Leaf start - SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
+    public boolean hasTasks() {
+        synchronized (this.stateLock) {
+            return !this.currentlyExecuting.isEmpty() || !this.oneTimeDelayed.isEmpty();
+        }
+    }
+    // Leaf end - SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
 }
diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
index 30d2ff810d8f9f1bdf785e9165c032eaa177ee43..875a5f644fae6a7d91c789c1bd49896bc8ca7732 100644
--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
+++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftEntity.java
@@ -85,7 +85,7 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
     private final CraftPersistentDataContainer persistentDataContainer = new CraftPersistentDataContainer(CraftEntity.DATA_TYPE_REGISTRY);
     protected net.kyori.adventure.pointer.Pointers adventure$pointers; // Paper - implement pointers
     // Paper start - Folia shedulers
-    public final io.papermc.paper.threadedregions.EntityScheduler taskScheduler = new io.papermc.paper.threadedregions.EntityScheduler(this);
+    public final io.papermc.paper.threadedregions.EntityScheduler taskScheduler; // = new io.papermc.paper.threadedregions.EntityScheduler(this); // SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
     private final io.papermc.paper.threadedregions.scheduler.FoliaEntityScheduler apiScheduler = new io.papermc.paper.threadedregions.scheduler.FoliaEntityScheduler(this);
 
     @Override
@@ -98,6 +98,7 @@ public abstract class CraftEntity implements org.bukkit.entity.Entity {
         this.server = server;
         this.entity = entity;
         this.entityType = CraftEntityType.minecraftToBukkit(entity.getType());
+        this.taskScheduler = new io.papermc.paper.threadedregions.EntityScheduler(this.entity.getServer(), this); // SparklyPaper - skip EntityScheduler's executeTick checks if there isn't any tasks to be run
     }
 
     // Purpur start - Fire Immunity API