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Mirror von https://github.com/PaperMC/Paper.git synchronisiert 2024-12-15 19:10:09 +01:00
Paper/patches/server/0417-Fix-for-large-move-vectors-crashing-server.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

87 Zeilen
6.0 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Sun, 17 May 2020 23:47:33 -0700
Subject: [PATCH] Fix for large move vectors crashing server
Check movement distance also based on current position.
diff --git a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
index 82f49aad1d0ce2d62bf61aa634ebef3711d4d930..d33cf08f7c47111823abbce481505946db249577 100644
--- a/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
+++ b/src/main/java/net/minecraft/server/network/ServerGamePacketListenerImpl.java
@@ -492,9 +492,9 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
float prevYaw = this.player.getYRot();
float prevPitch = this.player.getXRot();
// CraftBukkit end
- double d0 = entity.getX();
- double d1 = entity.getY();
- double d2 = entity.getZ();
+ double d0 = entity.getX();final double fromX = d0; // Paper - OBFHELPER
+ double d1 = entity.getY();final double fromY = d1; // Paper - OBFHELPER
+ double d2 = entity.getZ();final double fromZ = d2; // Paper - OBFHELPER
double d3 = ServerGamePacketListenerImpl.clampHorizontal(packet.getX()); final double toX = d3; // Paper - OBFHELPER
double d4 = ServerGamePacketListenerImpl.clampVertical(packet.getY()); final double toY = d4; // Paper - OBFHELPER
double d5 = ServerGamePacketListenerImpl.clampHorizontal(packet.getZ()); final double toZ = d5; // Paper - OBFHELPER
@@ -504,7 +504,16 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
double d7 = d4 - this.vehicleFirstGoodY;
double d8 = d5 - this.vehicleFirstGoodZ;
double d9 = entity.getDeltaMovement().lengthSqr();
- double d10 = d6 * d6 + d7 * d7 + d8 * d8;
+ // Paper start - fix large move vectors killing the server
+ double currDeltaX = toX - fromX;
+ double currDeltaY = toY - fromY;
+ double currDeltaZ = toZ - fromZ;
+ double d10 = Math.max(d6 * d6 + d7 * d7 + d8 * d8, (currDeltaX * currDeltaX + currDeltaY * currDeltaY + currDeltaZ * currDeltaZ) - 1);
+ double otherFieldX = d3 - this.vehicleLastGoodX;
+ double otherFieldY = d4 - this.vehicleLastGoodY - 1.0E-6D;
+ double otherFieldZ = d5 - this.vehicleLastGoodZ;
+ d10 = Math.max(d10, (otherFieldX * otherFieldX + otherFieldY * otherFieldY + otherFieldZ * otherFieldZ) - 1);
+ // Paper end - fix large move vectors killing the server
// CraftBukkit start - handle custom speeds and skipped ticks
this.allowedPlayerTicks += (System.currentTimeMillis() / 50) - this.lastTick;
@@ -550,9 +559,9 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
boolean flag = worldserver.noCollision(entity, entity.getBoundingBox().deflate(0.0625D));
- d6 = d3 - this.vehicleLastGoodX;
- d7 = d4 - this.vehicleLastGoodY - 1.0E-6D;
- d8 = d5 - this.vehicleLastGoodZ;
+ d6 = d3 - this.vehicleLastGoodX; // Paper - diff on change, used for checking large move vectors above
+ d7 = d4 - this.vehicleLastGoodY - 1.0E-6D; // Paper - diff on change, used for checking large move vectors above
+ d8 = d5 - this.vehicleLastGoodZ; // Paper - diff on change, used for checking large move vectors above
boolean flag1 = entity.verticalCollisionBelow;
if (entity instanceof LivingEntity) {
@@ -1253,7 +1262,16 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
double d7 = d1 - this.firstGoodY;
double d8 = d2 - this.firstGoodZ;
double d9 = this.player.getDeltaMovement().lengthSqr();
- double d10 = d6 * d6 + d7 * d7 + d8 * d8;
+ // Paper start - fix large move vectors killing the server
+ double currDeltaX = toX - prevX;
+ double currDeltaY = toY - prevY;
+ double currDeltaZ = toZ - prevZ;
+ double d10 = Math.max(d6 * d6 + d7 * d7 + d8 * d8, (currDeltaX * currDeltaX + currDeltaY * currDeltaY + currDeltaZ * currDeltaZ) - 1);
+ double otherFieldX = d0 - this.lastGoodX;
+ double otherFieldY = d1 - this.lastGoodY;
+ double otherFieldZ = d2 - this.lastGoodZ;
+ d10 = Math.max(d10, (otherFieldX * otherFieldX + otherFieldY * otherFieldY + otherFieldZ * otherFieldZ) - 1);
+ // Paper end - fix large move vectors killing the server
if (this.player.isSleeping()) {
if (d10 > 1.0D) {
@@ -1309,9 +1327,9 @@ public class ServerGamePacketListenerImpl extends ServerCommonPacketListenerImpl
AABB axisalignedbb = this.player.getBoundingBox();
- d6 = d0 - this.lastGoodX;
- d7 = d1 - this.lastGoodY;
- d8 = d2 - this.lastGoodZ;
+ d6 = d0 - this.lastGoodX; // Paper - diff on change, used for checking large move vectors above
+ d7 = d1 - this.lastGoodY; // Paper - diff on change, used for checking large move vectors above
+ d8 = d2 - this.lastGoodZ; // Paper - diff on change, used for checking large move vectors above
boolean flag1 = d7 > 0.0D;
if (this.player.onGround() && !packet.isOnGround() && flag1) {