Paper/patches/server/0401-Buffer-joins-to-world.patch
Bjarne Koll c5a10665b8
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.
2024-09-19 16:36:07 +02:00

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2.1 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shane Freeder <theboyetronic@gmail.com>
Date: Wed, 19 Aug 2020 05:05:54 +0100
Subject: [PATCH] Buffer joins to world
This patch buffers the number of logins which will attempt to join
the world per tick, this attempts to reduce the impact that join floods
has on the server
diff --git a/src/main/java/net/minecraft/network/Connection.java b/src/main/java/net/minecraft/network/Connection.java
index 38947f40864f3661df2eb4baa0aef5740b82f9d9..134810ac91d828d67759cd1ed56f11b71e292917 100644
--- a/src/main/java/net/minecraft/network/Connection.java
+++ b/src/main/java/net/minecraft/network/Connection.java
@@ -445,12 +445,26 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
}
}
+ private static final int MAX_PER_TICK = io.papermc.paper.configuration.GlobalConfiguration.get().misc.maxJoinsPerTick; // Paper - Buffer joins to world
+ private static int joinAttemptsThisTick; // Paper - Buffer joins to world
+ private static int currTick; // Paper - Buffer joins to world
public void tick() {
this.flushQueue();
+ // Paper start - Buffer joins to world
+ if (Connection.currTick != net.minecraft.server.MinecraftServer.currentTick) {
+ Connection.currTick = net.minecraft.server.MinecraftServer.currentTick;
+ Connection.joinAttemptsThisTick = 0;
+ }
+ // Paper end - Buffer joins to world
PacketListener packetlistener = this.packetListener;
if (packetlistener instanceof TickablePacketListener tickablepacketlistener) {
+ // Paper start - Buffer joins to world
+ if (!(this.packetListener instanceof net.minecraft.server.network.ServerLoginPacketListenerImpl loginPacketListener)
+ || loginPacketListener.state != net.minecraft.server.network.ServerLoginPacketListenerImpl.State.VERIFYING
+ || Connection.joinAttemptsThisTick++ < MAX_PER_TICK) {
tickablepacketlistener.tick();
+ } // Paper end - Buffer joins to world
}
if (!this.isConnected() && !this.disconnectionHandled) {