Leaf/patches/server/0007-Pufferfish-Optimize-mob-spawning.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Kevin Raneri <kevin.raneri@gmail.com>
Date: Wed, 10 Nov 2021 00:37:03 -0500
Subject: [PATCH] Pufferfish: Optimize mob spawning

Original license: GPL v3
Original project: https://github.com/pufferfish-gg/Pufferfish

Co-authored-by: booky10 <boooky10@gmail.com>

This patch aims to reduce the main-thread impact of mob spawning by
offloading as much work as possible to other threads. It is possible for
inconsistencies to come up, but when they happen they never interfere
with the server's operation (they don't produce errors), and side
effects are limited to more or less mobs being spawned in any particular
tick.

It is possible to disable this optimization if it is not required or if
it interferes with any plugins. On servers with thousands of entities,
this can result in performance gains of up to 15%, which is significant
and, in my opinion, worth the low risk of minor mob-spawning-related
inconsistencies.

diff --git a/src/main/java/ca/spottedleaf/moonrise/common/list/IteratorSafeOrderedReferenceSet.java b/src/main/java/ca/spottedleaf/moonrise/common/list/IteratorSafeOrderedReferenceSet.java
index c21e00812f1aaa1279834a0562d360d6b89e146c..877d2095a066854939f260ca4b0b8c7b5abb620f 100644
--- a/src/main/java/ca/spottedleaf/moonrise/common/list/IteratorSafeOrderedReferenceSet.java
+++ b/src/main/java/ca/spottedleaf/moonrise/common/list/IteratorSafeOrderedReferenceSet.java
@@ -18,7 +18,7 @@ public final class IteratorSafeOrderedReferenceSet<E> {
 
     private final double maxFragFactor;
 
-    private int iteratorCount;
+    private final java.util.concurrent.atomic.AtomicInteger iteratorCount = new java.util.concurrent.atomic.AtomicInteger(); // Pufferfish - async mob spawning
 
     public IteratorSafeOrderedReferenceSet() {
         this(16, 0.75f, 16, 0.2);
@@ -79,7 +79,7 @@ public final class IteratorSafeOrderedReferenceSet<E> {
     }
 
     public int createRawIterator() {
-        ++this.iteratorCount;
+        this.iteratorCount.incrementAndGet(); // Pufferfish - async mob spawning
         if (this.indexMap.isEmpty()) {
             return -1;
         } else {
@@ -100,7 +100,7 @@ public final class IteratorSafeOrderedReferenceSet<E> {
     }
 
     public void finishRawIterator() {
-        if (--this.iteratorCount == 0) {
+        if (this.iteratorCount.decrementAndGet() == 0) { // Pufferfish - async mob spawning
             if (this.getFragFactor() >= this.maxFragFactor) {
                 this.defrag();
             }
@@ -117,7 +117,7 @@ public final class IteratorSafeOrderedReferenceSet<E> {
                 throw new IllegalStateException();
             }
             this.listElements[index] = null;
-            if (this.iteratorCount == 0 && this.getFragFactor() >= this.maxFragFactor) {
+            if (this.iteratorCount.get() == 0 && this.getFragFactor() >= this.maxFragFactor) { // Pufferfish - async mob spawning
                 this.defrag();
             }
             //this.check();
@@ -219,7 +219,7 @@ public final class IteratorSafeOrderedReferenceSet<E> {
     }
 
     public IteratorSafeOrderedReferenceSet.Iterator<E> iterator(final int flags) {
-        ++this.iteratorCount;
+        this.iteratorCount.incrementAndGet(); // Pufferfish - async mob spawning
         return new BaseIterator<>(this, true, (flags & ITERATOR_FLAG_SEE_ADDITIONS) != 0 ? Integer.MAX_VALUE : this.listSize);
     }
 
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 05f805c7e7a6ff6d40b9f86aaac5362ab516be3f..654c381c210d9e353df8f7bca0cd7a434d997a8f 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -309,6 +309,8 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
     public volatile boolean abnormalExit = false; // Paper
     public static final long SERVER_INIT = System.nanoTime(); // Paper - Lag compensation
 
+    public gg.pufferfish.pufferfish.util.AsyncExecutor mobSpawnExecutor = new gg.pufferfish.pufferfish.util.AsyncExecutor("MobSpawning"); // Pufferfish - optimize mob spawning
+
     public static <S extends MinecraftServer> S spin(Function<Thread, S> serverFactory) {
         AtomicReference<S> atomicreference = new AtomicReference();
         Thread thread = new ca.spottedleaf.moonrise.common.util.TickThread(() -> { // Paper - rewrite chunk system
diff --git a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
index 2b289f84ffe49b46f1ca85893a6e3255f366bc5c..5ed84fbccf65aa91a4e8a19566207e1e7bb49620 100644
--- a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
+++ b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
@@ -371,6 +371,7 @@ public class DedicatedServer extends MinecraftServer implements ServerInterface
                 DedicatedServer.LOGGER.info("JMX monitoring enabled");
             }
 
+            if (org.dreeam.leaf.config.modules.async.AsyncMobSpawning.enabled) mobSpawnExecutor.start(); // Pufferfish
             return true;
         }
     }
diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
index c520d824630e8b5c569c3213d019b2548120a50f..e9d307dacea2f9b11cda5ecf5a06c7df09d1de90 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -127,6 +127,9 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
     // Paper end - rewrite chunk system
     private ServerChunkCache.ChunkAndHolder[] iterationCopy; // Paper - chunk tick iteration optimisations
 
+    public boolean firstRunSpawnCounts = true; // Pufferfish
+    public final java.util.concurrent.atomic.AtomicBoolean _pufferfish_spawnCountsReady = new java.util.concurrent.atomic.AtomicBoolean(false); // Pufferfish - optimize countmobs
+
     public ServerChunkCache(ServerLevel world, LevelStorageSource.LevelStorageAccess session, DataFixer dataFixer, StructureTemplateManager structureTemplateManager, Executor workerExecutor, ChunkGenerator chunkGenerator, int viewDistance, int simulationDistance, boolean dsync, ChunkProgressListener worldGenerationProgressListener, ChunkStatusUpdateListener chunkStatusChangeListener, Supplier<DimensionDataStorage> persistentStateManagerFactory) {
         this.level = world;
         this.mainThreadProcessor = new ServerChunkCache.MainThreadExecutor(world);
@@ -454,6 +457,7 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
                 // Paper start - Optional per player mob spawns
                 int naturalSpawnChunkCount = k;
                 if ((this.spawnFriendlies || this.spawnEnemies) && this.level.paperConfig().entities.spawning.perPlayerMobSpawns) { // don't count mobs when animals and monsters are disabled
+                    if (!org.dreeam.leaf.config.modules.async.AsyncMobSpawning.enabled) { // Pufferfish - moved down when async processing
                     // re-set mob counts
                     for (ServerPlayer player : this.level.players) {
                         // Paper start - per player mob spawning backoff
@@ -468,14 +472,18 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
                         }
                         // Paper end - per player mob spawning backoff
                     }
-                    spawnercreature_d = NaturalSpawner.createState(naturalSpawnChunkCount, this.level.getAllEntities(), this::getFullChunk, null, true);
+                    lastSpawnState = NaturalSpawner.createState(naturalSpawnChunkCount, this.level.getAllEntities(), this::getFullChunk, null, true); // Pufferfish - async mob spawning
+                    } // Pufferfish - (endif) moved down when async processing
                 } else {
-                    spawnercreature_d = NaturalSpawner.createState(naturalSpawnChunkCount, this.level.getAllEntities(), this::getFullChunk, !this.level.paperConfig().entities.spawning.perPlayerMobSpawns ? new LocalMobCapCalculator(this.chunkMap) : null, false);
+                    // Pufferfish start - async mob spawning
+                    lastSpawnState = NaturalSpawner.createState(naturalSpawnChunkCount, this.level.getAllEntities(), this::getFullChunk, !this.level.paperConfig().entities.spawning.perPlayerMobSpawns ? new LocalMobCapCalculator(this.chunkMap) : null, false);
+                    _pufferfish_spawnCountsReady.set(true);
+                    // Pufferfish end
                 }
                 // Paper end - Optional per player mob spawns
                 this.level.timings.countNaturalMobs.stopTiming(); // Paper - timings
 
-                this.lastSpawnState = spawnercreature_d;
+                //this.lastSpawnState = spawnercreature_d; // Pufferfish - this is managed asynchronously
                 // Gale start - MultiPaper - skip unnecessary mob spawning computations
                 } else {
                     spawnercreature_d = null;
@@ -503,8 +511,8 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
 
                     if (true && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair)) { // Paper - rewrite chunk system
                         chunk1.incrementInhabitedTime(j);
-                        if (flagAndHasNaturalSpawn && (this.spawnEnemies || this.spawnFriendlies) && this.level.getWorldBorder().isWithinBounds(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair, true)) { // Spigot // Gale - MultiPaper - skip unnecessary mob spawning computations
-                            NaturalSpawner.spawnForChunk(this.level, chunk1, spawnercreature_d, this.spawnFriendlies, this.spawnEnemies, flag1);
+                        if (flagAndHasNaturalSpawn && (!org.dreeam.leaf.config.modules.async.AsyncMobSpawning.enabled || _pufferfish_spawnCountsReady.get()) && (this.spawnEnemies || this.spawnFriendlies) && this.level.getWorldBorder().isWithinBounds(chunkcoordintpair) && this.chunkMap.anyPlayerCloseEnoughForSpawning(chunkcoordintpair, true)) { // Spigot // Gale - MultiPaper - skip unnecessary mob spawning computations // Pufferfish
+                            NaturalSpawner.spawnForChunk(this.level, chunk1, lastSpawnState, this.spawnFriendlies, this.spawnEnemies, flag1); // Pufferfish
                         }
 
                         if (true) { // Paper - rewrite chunk system
@@ -544,6 +552,43 @@ public class ServerChunkCache extends ChunkSource implements ca.spottedleaf.moon
             this.level.timings.broadcastChunkUpdates.stopTiming(); // Paper - timing
             // Paper end - chunk tick iteration optimisations
         }
+
+        // Pufferfish start - optimize mob spawning
+        if (org.dreeam.leaf.config.modules.async.AsyncMobSpawning.enabled) {
+            for (ServerPlayer player : this.level.players) {
+                // Paper start - per player mob spawning backoff
+                for (int ii = 0; ii < ServerPlayer.MOBCATEGORY_TOTAL_ENUMS; ii++) {
+                    player.mobCounts[ii] = 0;
+
+                    int newBackoff = player.mobBackoffCounts[ii] - 1; // TODO make configurable bleed // TODO use nonlinear algorithm?
+                    if (newBackoff < 0) {
+                        newBackoff = 0;
+                    }
+                    player.mobBackoffCounts[ii] = newBackoff;
+                }
+                // Paper end - per player mob spawning backoff
+            }
+            if (firstRunSpawnCounts) {
+                firstRunSpawnCounts = false;
+                _pufferfish_spawnCountsReady.set(true);
+            }
+            if (_pufferfish_spawnCountsReady.getAndSet(false)) {
+                net.minecraft.server.MinecraftServer.getServer().mobSpawnExecutor.submit(() -> {
+                    int mapped = distanceManager.getNaturalSpawnChunkCount();
+                    ca.spottedleaf.moonrise.common.list.IteratorSafeOrderedReferenceSet.Iterator<Entity> objectiterator =
+                            level.entityTickList.entities.iterator(ca.spottedleaf.moonrise.common.list.IteratorSafeOrderedReferenceSet.ITERATOR_FLAG_SEE_ADDITIONS);
+                    try {
+                        gg.pufferfish.pufferfish.util.IterableWrapper<Entity> wrappedIterator =
+                                new gg.pufferfish.pufferfish.util.IterableWrapper<>(objectiterator);
+                        lastSpawnState = NaturalSpawner.createState(mapped, wrappedIterator, this::getFullChunk, null, true);
+                    } finally {
+                        objectiterator.finishedIterating();
+                    }
+                    _pufferfish_spawnCountsReady.set(true);
+                });
+            }
+        }
+        // Pufferfish end
     }
 
     // Gale start - MultiPaper - skip unnecessary mob spawning computations
diff --git a/src/main/java/net/minecraft/world/level/entity/EntityTickList.java b/src/main/java/net/minecraft/world/level/entity/EntityTickList.java
index d8b4196adf955f8d414688dc451caac2d9c609d9..80a43def4912a3228cd95117d5c2aac68798b4ec 100644
--- a/src/main/java/net/minecraft/world/level/entity/EntityTickList.java
+++ b/src/main/java/net/minecraft/world/level/entity/EntityTickList.java
@@ -9,7 +9,7 @@ import javax.annotation.Nullable;
 import net.minecraft.world.entity.Entity;
 
 public class EntityTickList {
-    private final ca.spottedleaf.moonrise.common.list.IteratorSafeOrderedReferenceSet<net.minecraft.world.entity.Entity> entities = new ca.spottedleaf.moonrise.common.list.IteratorSafeOrderedReferenceSet<>(); // Paper - rewrite chunk system
+    public final ca.spottedleaf.moonrise.common.list.IteratorSafeOrderedReferenceSet<net.minecraft.world.entity.Entity> entities = new ca.spottedleaf.moonrise.common.list.IteratorSafeOrderedReferenceSet<>(); // Paper - rewrite chunk system // Pufferfish - private->public
 
     private void ensureActiveIsNotIterated() {
         // Paper - rewrite chunk system
diff --git a/src/main/java/org/dreeam/leaf/config/modules/async/AsyncMobSpawning.java b/src/main/java/org/dreeam/leaf/config/modules/async/AsyncMobSpawning.java
new file mode 100644
index 0000000000000000000000000000000000000000..9a9cbb8ab1281fa1e8e98ed2d6fec4f68cfd002a
--- /dev/null
+++ b/src/main/java/org/dreeam/leaf/config/modules/async/AsyncMobSpawning.java
@@ -0,0 +1,34 @@
+package org.dreeam.leaf.config.modules.async;
+
+import org.dreeam.leaf.config.ConfigModules;
+import org.dreeam.leaf.config.EnumConfigCategory;
+
+public class AsyncMobSpawning extends ConfigModules {
+
+    public String getBasePath() {
+        return EnumConfigCategory.ASYNC.getBaseKeyName() + ".async-mob-spawning";
+    }
+
+    public static boolean enabled = true;
+    public static boolean asyncMobSpawningInitialized;
+
+    @Override
+    public void onLoaded() {
+        config.addCommentRegionBased(getBasePath(), """
+                Whether or not asynchronous mob spawning should be enabled.
+                On servers with many entities, this can improve performance by up to 15%. You must have
+                paper's per-player-mob-spawns setting set to true for this to work.
+                One quick note - this does not actually spawn mobs async (that would be very unsafe).
+                This just offloads some expensive calculations that are required for mob spawning.""",
+                """
+                是否异步化生物生成.
+                在实体较多的服务器上, 异步生成可最高带来15%的性能提升.
+                须在Paper配置文件中打开 per-player-mob-spawns 才能生效.""");
+
+        // This prevents us from changing the value during a reload.
+        if (!asyncMobSpawningInitialized) {
+            asyncMobSpawningInitialized = true;
+            enabled = config.getBoolean(getBasePath() + ".enabled", enabled);
+        }
+    }
+}