From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <spottedleaf@spottedleaf.dev>
Date: Mon, 6 Apr 2020 04:20:44 -0700
Subject: [PATCH] Execute chunk tasks mid-tick
This will help the server load chunks if tick times are high.
diff --git a/src/main/java/co/aikar/timings/MinecraftTimings.java b/src/main/java/co/aikar/timings/MinecraftTimings.java
index b27021a42cbed3f0648a8d0903d00d03922ae221..eada966d7f108a6081be7a848f5c1dfcb1eed676 100644
--- a/src/main/java/co/aikar/timings/MinecraftTimings.java
+++ b/src/main/java/co/aikar/timings/MinecraftTimings.java
@@ -45,6 +45,8 @@ public final class MinecraftTimings {
public static final Timing antiXrayUpdateTimer = Timings.ofSafe("anti-xray - update");
public static final Timing antiXrayObfuscateTimer = Timings.ofSafe("anti-xray - obfuscate");
+ public static final Timing midTickChunkTasks = Timings.ofSafe("Mid Tick Chunk Tasks");
+
private static final Map<Class<?>, String> taskNameCache = new MapMaker().weakKeys().makeMap();
private MinecraftTimings() {}
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 088334869cb62797a1e1d1bbb6187f03189d852d..c245c1f4611f7273c8da629f774e0c64e9f98fc2 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -332,6 +332,76 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
return s0;
}
+ // Paper start - execute chunk tasks mid tick
+ static final long CHUNK_TASK_QUEUE_BACKOFF_MIN_TIME = 25L * 1000L; // 25us
+ static final long MAX_CHUNK_EXEC_TIME = 1000L; // 1us
+
+ static final long TASK_EXECUTION_FAILURE_BACKOFF = 5L * 1000L; // 5us
+
+ private static long lastMidTickExecute;
+ private static long lastMidTickExecuteFailure;
+
+ private boolean tickMidTickTasks() {
+ // give all worlds a fair chance at by targetting them all.
+ // if we execute too many tasks, that's fine - we have logic to correctly handle overuse of allocated time.
+ boolean executed = false;
+ for (ServerLevel world : this.getAllLevels()) {
+ long currTime = System.nanoTime();
+ if (currTime - world.lastMidTickExecuteFailure <= TASK_EXECUTION_FAILURE_BACKOFF) {
+ continue;
+ }
+ if (!world.getChunkSource().pollTask()) {
+ // we need to back off if this fails
+ world.lastMidTickExecuteFailure = currTime;
+ } else {
+ executed = true;
+ }
+ }
+
+ return executed;
+ }
+
+ public final void executeMidTickTasks() {
+ org.spigotmc.AsyncCatcher.catchOp("mid tick chunk task execution");
+ long startTime = System.nanoTime();
+ if ((startTime - lastMidTickExecute) <= CHUNK_TASK_QUEUE_BACKOFF_MIN_TIME || (startTime - lastMidTickExecuteFailure) <= TASK_EXECUTION_FAILURE_BACKOFF) {
+ // it's shown to be bad to constantly hit the queue (chunk loads slow to a crawl), even if no tasks are executed.
+ // so, backoff to prevent this
+ return;
+ }
+
+ co.aikar.timings.MinecraftTimings.midTickChunkTasks.startTiming();
+ try {
+ for (;;) {
+ boolean moreTasks = this.tickMidTickTasks();
+ long currTime = System.nanoTime();
+ long diff = currTime - startTime;
+
+ if (!moreTasks || diff >= MAX_CHUNK_EXEC_TIME) {
+ if (!moreTasks) {
+ lastMidTickExecuteFailure = currTime;
+ }
+
+ // note: negative values reduce the time
+ long overuse = diff - MAX_CHUNK_EXEC_TIME;
+ if (overuse >= (10L * 1000L * 1000L)) { // 10ms
+ // make sure something like a GC or dumb plugin doesn't screw us over...
+ overuse = 10L * 1000L * 1000L; // 10ms
+ }
+
+ double overuseCount = (double)overuse/(double)MAX_CHUNK_EXEC_TIME;
+ long extraSleep = (long)Math.round(overuseCount*CHUNK_TASK_QUEUE_BACKOFF_MIN_TIME);
+
+ lastMidTickExecute = currTime + extraSleep;
+ return;
+ }
+ }
+ } finally {
+ co.aikar.timings.MinecraftTimings.midTickChunkTasks.stopTiming();
+ }
+ }
+ // Paper end - execute chunk tasks mid tick
+
public MinecraftServer(OptionSet options, DataPackConfig datapackconfiguration, Thread thread, RegistryAccess.RegistryHolder iregistrycustom_dimension, LevelStorageSource.LevelStorageAccess convertable_conversionsession, WorldData savedata, PackRepository resourcepackrepository, Proxy proxy, DataFixer datafixer, ServerResources datapackresources, @Nullable MinecraftSessionService minecraftsessionservice, @Nullable GameProfileRepository gameprofilerepository, @Nullable GameProfileCache usercache, ChunkProgressListenerFactory worldloadlistenerfactory) {
super("Server");
SERVER = this; // Paper - better singleton
@@ -1312,6 +1382,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
private boolean pollTaskInternal() {
if (super.pollTask()) {
+ this.executeMidTickTasks(); // Paper - execute chunk tasks mid tick
return true;
} else {
if (this.haveTime()) {
diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
index ad352b4b67632f9984c4d10994a9acfe434a4996..df415f79dfd2ae9a709747b112022b38437daac4 100644
--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
@@ -1023,6 +1023,7 @@ public class ServerChunkCache extends ChunkSource {
iterator1 = shuffled.iterator();
}
+ int chunksTicked = 0; // Paper
try {
while (iterator1.hasNext()) {
LevelChunk chunk1 = iterator1.next();
@@ -1044,6 +1045,7 @@ public class ServerChunkCache extends ChunkSource {
if (this.level.shouldTickBlocksAt(chunkcoordintpair.toLong())) {
this.level.tickChunk(chunk1, k);
+ if ((chunksTicked++ & 1) == 0) net.minecraft.server.MinecraftServer.getServer().executeMidTickTasks(); // Paper
}
}
// Paper start - optimise chunk tick iteration
diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
index 5e65df1a9a8282c4ffa06801379b79ab0ed1b45c..7e837b2896cac64a982d9025c4e190dfa7ebc451 100644
--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
+++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
@@ -201,7 +201,9 @@ public class ServerLevel extends Level implements WorldGenLevel {
private final StructureFeatureManager structureFeatureManager;
private final StructureCheck structureCheck;
private final boolean tickTime;
-
+ // Paper start - execute chunk tasks mid tick
+ public long lastMidTickExecuteFailure;
+ // Paper end - execute chunk tasks mid tick
// CraftBukkit start
private int tickPosition;
diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
index 3831895e2219d846022500553d9b714c7d654b3a..86bcedec97f1bc95621380da6ad074bdcc4bfeab 100644
--- a/src/main/java/net/minecraft/world/level/Level.java
+++ b/src/main/java/net/minecraft/world/level/Level.java
@@ -896,6 +896,7 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
public <T extends Entity> void guardEntityTick(Consumer<T> tickConsumer, T entity) {
try {
tickConsumer.accept(entity);
+ MinecraftServer.getServer().executeMidTickTasks(); // Paper - execute chunk tasks mid tick
} catch (Throwable throwable) {
if (throwable instanceof ThreadDeath) throw throwable; // Paper
// Paper start - Prevent tile entity and entity crashes