13
0
geforkt von Mirrors/Paper

Remove wall-time / unused skip tick protection (#11412)

Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.
Dieser Commit ist enthalten in:
Bjarne Koll 2024-09-19 16:36:07 +02:00
Ursprung 5d6137bcc9
Commit f65939c6bd
6 geänderte Dateien mit 166 neuen und 46 gelöschten Zeilen

Datei anzeigen

@ -105,9 +105,9 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
long i;
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
}
}
// Spigot start
++MinecraftServer.currentTickLong; // Paper - track current tick as a long
- if ( tickCount++ % MinecraftServer.SAMPLE_INTERVAL == 0 )
- {
- long curTime = Util.getMillis();

Datei anzeigen

@ -128,7 +128,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
// Spigot start
public static final int TPS = 20;
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
public static long currentTickLong = 0L; // Paper - track current tick as a long
public final io.papermc.paper.configuration.PaperConfigurations paperConfigurations; // Paper - add paper configuration files
public boolean isIteratingOverLevels = false; // Paper - Throw exception on world create while being ticked
+ public volatile Thread shutdownThread; // Paper

Datei anzeigen

@ -4419,14 +4419,6 @@ diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
public final double[] recentTps = new double[ 3 ];
// Spigot end
public final io.papermc.paper.configuration.PaperConfigurations paperConfigurations; // Paper - add paper configuration files
+ public static long currentTickLong = 0L; // Paper - track current tick as a long
public static <S extends MinecraftServer> S spin(Function<Thread, S> serverFactory) {
AtomicReference<S> atomicreference = new AtomicReference();
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
MinecraftServer.LOGGER.error("Failed to unlock level {}", this.storageSource.getLevelId(), ioexception1);
}
@ -4437,14 +4429,6 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
if (org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly) {
MinecraftServer.LOGGER.info("Saving usercache.json");
this.getProfileCache().save();
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
}
}
// Spigot start
+ ++MinecraftServer.currentTickLong; // Paper - track current tick as a long
if ( tickCount++ % MinecraftServer.SAMPLE_INTERVAL == 0 )
{
long curTime = Util.getMillis();
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
MinecraftServer.LOGGER.debug("Autosave finished");
SpigotTimings.worldSaveTimer.stopTiming(); // Spigot

Datei anzeigen

@ -0,0 +1,163 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Bjarne Koll <git@lynxplay.dev>
Date: Mon, 16 Sep 2024 23:07:29 +0200
Subject: [PATCH] Remove wall-time / unused skip tick protection
Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.
To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.
These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.
Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.
diff --git a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
+++ b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
@@ -0,0 +0,0 @@ public class ItemEntity extends Entity implements TraceableEntity {
@Nullable
public UUID target;
public final float bobOffs;
- private int lastTick = MinecraftServer.currentTick - 1; // CraftBukkit
+ // private int lastTick = MinecraftServer.currentTick - 1; // CraftBukkit // Paper - remove anti tick skipping measures / wall time
public boolean canMobPickup = true; // Paper - Item#canEntityPickup
private int despawnRate = -1; // Paper - Alternative item-despawn-rate
public net.kyori.adventure.util.TriState frictionState = net.kyori.adventure.util.TriState.NOT_SET; // Paper - Friction API
@@ -0,0 +0,0 @@ public class ItemEntity extends Entity implements TraceableEntity {
this.discard(EntityRemoveEvent.Cause.DESPAWN); // CraftBukkit - add Bukkit remove cause
} else {
super.tick();
- // CraftBukkit start - Use wall time for pickup and despawn timers
- int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
- if (this.pickupDelay != 32767) this.pickupDelay -= elapsedTicks;
- if (this.age != -32768) this.age += elapsedTicks;
- this.lastTick = MinecraftServer.currentTick;
- // CraftBukkit end
+ // Paper start - remove anti tick skipping measures / wall time - revert to vanilla
+ if (this.pickupDelay > 0 && this.pickupDelay != 32767) {
+ --this.pickupDelay;
+ }
+ // Paper end - remove anti tick skipping measures / wall time - revert to vanilla
this.xo = this.getX();
this.yo = this.getY();
@@ -0,0 +0,0 @@ public class ItemEntity extends Entity implements TraceableEntity {
this.mergeWithNeighbours();
}
- /* CraftBukkit start - moved up
+ // Paper - remove anti tick skipping measures / wall time - revert to vanilla /* CraftBukkit start - moved up
if (this.age != -32768) {
++this.age;
}
@@ -0,0 +0,0 @@ public class ItemEntity extends Entity implements TraceableEntity {
// Spigot start - copied from above
@Override
public void inactiveTick() {
- // CraftBukkit start - Use wall time for pickup and despawn timers
- int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
- if (this.pickupDelay != 32767) this.pickupDelay -= elapsedTicks;
- if (this.age != -32768) this.age += elapsedTicks;
- this.lastTick = MinecraftServer.currentTick;
- // CraftBukkit end
+ // Paper start - remove anti tick skipping measures / wall time - copied from above
+ if (this.pickupDelay > 0 && this.pickupDelay != 32767) {
+ --this.pickupDelay;
+ }
+ if (this.age != -32768) {
+ ++this.age;
+ }
+ // Paper end - remove anti tick skipping measures / wall time - copied from above
if (!this.level().isClientSide && this.age >= this.despawnRate) { // Spigot // Paper - Alternative item-despawn-rate
// CraftBukkit start - fire ItemDespawnEvent
diff --git a/src/main/java/net/minecraft/world/entity/monster/Zombie.java b/src/main/java/net/minecraft/world/entity/monster/Zombie.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/monster/Zombie.java
+++ b/src/main/java/net/minecraft/world/entity/monster/Zombie.java
@@ -0,0 +0,0 @@ public class Zombie extends Monster {
private boolean canBreakDoors;
private int inWaterTime;
public int conversionTime;
- private int lastTick = MinecraftServer.currentTick; // CraftBukkit - add field
+ // private int lastTick = MinecraftServer.currentTick; // CraftBukkit - add field // Paper - remove anti tick skipping measures / wall time
private boolean shouldBurnInDay = true; // Paper - Add more Zombie API
public Zombie(EntityType<? extends Zombie> type, Level world) {
@@ -0,0 +0,0 @@ public class Zombie extends Monster {
public void tick() {
if (!this.level().isClientSide && this.isAlive() && !this.isNoAi()) {
if (this.isUnderWaterConverting()) {
- // CraftBukkit start - Use wall time instead of ticks for conversion
- int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
- this.conversionTime -= elapsedTicks;
- // CraftBukkit end
+ --this.conversionTime; // Paper - remove anti tick skipping measures / wall time
if (this.conversionTime < 0) {
this.doUnderWaterConversion();
}
@@ -0,0 +0,0 @@ public class Zombie extends Monster {
}
super.tick();
- this.lastTick = MinecraftServer.currentTick; // CraftBukkit
+ // this.lastTick = MinecraftServer.currentTick; // CraftBukkit // Paper - remove anti tick skipping measures / wall time
}
@Override
@@ -0,0 +0,0 @@ public class Zombie extends Monster {
}
// Paper end - Add more Zombie API
public void startUnderWaterConversion(int ticksUntilWaterConversion) {
- this.lastTick = MinecraftServer.currentTick; // CraftBukkit
+ // this.lastTick = MinecraftServer.currentTick; // CraftBukkit // Paper - remove anti tick skipping measures / wall time
this.conversionTime = ticksUntilWaterConversion;
this.getEntityData().set(Zombie.DATA_DROWNED_CONVERSION_ID, true);
}
diff --git a/src/main/java/net/minecraft/world/level/block/entity/BrewingStandBlockEntity.java b/src/main/java/net/minecraft/world/level/block/entity/BrewingStandBlockEntity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/level/block/entity/BrewingStandBlockEntity.java
+++ b/src/main/java/net/minecraft/world/level/block/entity/BrewingStandBlockEntity.java
@@ -0,0 +0,0 @@ public class BrewingStandBlockEntity extends BaseContainerBlockEntity implements
public int fuel;
protected final ContainerData dataAccess;
// CraftBukkit start - add fields and methods
- private int lastTick = MinecraftServer.currentTick;
+ // private int lastTick = MinecraftServer.currentTick; // Paper - remove anti tick skipping measures / wall time
public List<HumanEntity> transaction = new java.util.ArrayList<HumanEntity>();
private int maxStack = MAX_STACK;
@@ -0,0 +0,0 @@ public class BrewingStandBlockEntity extends BaseContainerBlockEntity implements
boolean flag1 = blockEntity.brewTime > 0;
ItemStack itemstack1 = (ItemStack) blockEntity.items.get(3);
- // CraftBukkit start - Use wall time instead of ticks for brewing
- int elapsedTicks = MinecraftServer.currentTick - blockEntity.lastTick;
- blockEntity.lastTick = MinecraftServer.currentTick;
+ // Paper - remove anti tick skipping measures / wall time
if (flag1) {
- blockEntity.brewTime -= elapsedTicks;
+ --blockEntity.brewTime; // Paper - remove anti tick skipping measures / wall time - revert to vanilla
boolean flag2 = blockEntity.brewTime <= 0; // == -> <=
// CraftBukkit end

Datei anzeigen

@ -11,9 +11,9 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
public final double[] recentTps = new double[ 3 ];
// Spigot end
public final io.papermc.paper.configuration.PaperConfigurations paperConfigurations; // Paper - add paper configuration files
public static long currentTickLong = 0L; // Paper - track current tick as a long
+ public boolean isIteratingOverLevels = false; // Paper - Throw exception on world create while being ticked
public static <S extends MinecraftServer> S spin(Function<Thread, S> serverFactory) {

Datei anzeigen

@ -1,27 +0,0 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 24 Mar 2019 18:09:20 -0400
Subject: [PATCH] don't go below 0 for pickupDelay, breaks picking up items
vanilla checks for == 0
diff --git a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
--- a/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
+++ b/src/main/java/net/minecraft/world/entity/item/ItemEntity.java
@@ -0,0 +0,0 @@ public class ItemEntity extends Entity implements TraceableEntity {
// CraftBukkit start - Use wall time for pickup and despawn timers
int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
if (this.pickupDelay != 32767) this.pickupDelay -= elapsedTicks;
+ this.pickupDelay = Math.max(0, this.pickupDelay); // Paper - don't go below 0
if (this.age != -32768) this.age += elapsedTicks;
this.lastTick = MinecraftServer.currentTick;
// CraftBukkit end
@@ -0,0 +0,0 @@ public class ItemEntity extends Entity implements TraceableEntity {
// CraftBukkit start - Use wall time for pickup and despawn timers
int elapsedTicks = MinecraftServer.currentTick - this.lastTick;
if (this.pickupDelay != 32767) this.pickupDelay -= elapsedTicks;
+ this.pickupDelay = Math.max(0, this.pickupDelay); // Paper - don't go below 0
if (this.age != -32768) this.age += elapsedTicks;
this.lastTick = MinecraftServer.currentTick;
// CraftBukkit end