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.
This commit is contained in:
Bjarne Koll 2024-09-19 16:36:07 +02:00 committed by GitHub
parent 5c82955733
commit c5a10665b8
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
794 changed files with 402 additions and 282 deletions

View file

@ -533,7 +533,7 @@ index 0000000000000000000000000000000000000000..790bad0494454ca12ee152e3de6da3da
+ }
+}
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index e9d56d75b7c648f04d3a56942b2866090c570129..57ec168bac3727feb734e28cebc680328c1c4aec 100644
index 46e03617bb32e4037d700c1b3698d397bd75de5c..2f57739431eb695149019724e2923f0d02e88d07 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -43,7 +43,6 @@ import java.util.Set;
@ -553,7 +553,7 @@ index e9d56d75b7c648f04d3a56942b2866090c570129..57ec168bac3727feb734e28cebc68032
import org.bukkit.event.server.ServerLoadEvent;
// CraftBukkit end
@@ -1702,7 +1699,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
@@ -1700,7 +1697,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
@DontObfuscate
public String getServerModName() {
@ -590,7 +590,7 @@ index f077b8ff0bf0d96628db3569132696b68fd79921..5f11f5b16766f9d1d5640ae037e259be
value.append("\n Plugins: {");
for (Plugin plugin : Bukkit.getPluginManager().getPlugins()) {
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index acab477a4a026799319054c2eb4d0f2c99ab3d83..2a36e562967ec6174efe456e489c50ca10ba47e5 100644
index 7d6d817f951811aad0f2ccea567e558bad1242fa..19d2b38cd4397cb53fc2ed3f0e5df5c66223fd5f 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -11,8 +11,6 @@ import com.google.common.collect.MapMaker;
@ -692,7 +692,7 @@ index 8da38624b5867ce88bdb3036e1ed6d99fc626f31..2097be352dc585b805dc73194cec0956
t.printStackTrace();
}
diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
index 9576cabff99d154ef77595b074082adf9212698d..e091356ee1fa3ec09839de6ef5c450824ea40844 100644
index 9383bf47404fca8d008d5c401ed37ddaa7bef4f7..d08b01fef9928f2239c8663cf90219dc7acad58c 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
@@ -453,6 +453,11 @@ public final class CraftMagicNumbers implements UnsafeValues {