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.

1 files changed, 72 insertions, 0 deletions

diff --git a/patches/server/0902-Fix-strikeLightningEffect-powers-lightning-rods-and-.patch b/patches/server/0902-Fix-strikeLightningEffect-powers-lightning-rods-and-.patch
new file mode 100644
index 0000000000..da48750747
--- /dev/null
+++ b/patches/server/0902-Fix-strikeLightningEffect-powers-lightning-rods-and-.patch
@@ -0,0 +1,72 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Tamion <[email protected]>
+Date: Sat, 30 Sep 2023 12:36:14 +0200
+Subject: [PATCH] Fix strikeLightningEffect powers lightning rods and clears
+ copper
+
+
+diff --git a/src/main/java/net/minecraft/world/entity/LightningBolt.java b/src/main/java/net/minecraft/world/entity/LightningBolt.java
+index 0471d9c85af02133f99cca4e181b83b58a3f1abc..4f701788bd21b61cad251a3a88f9bc416fb99051 100644
+--- a/src/main/java/net/minecraft/world/entity/LightningBolt.java
++++ b/src/main/java/net/minecraft/world/entity/LightningBolt.java
+@@ -47,6 +47,7 @@ public class LightningBolt extends Entity {
+     private ServerPlayer cause;
+     private final Set<Entity> hitEntities = Sets.newHashSet();
+     private int blocksSetOnFire;
++    public boolean isEffect; // Paper - Properly handle lightning effects api
+ 
+     public LightningBolt(EntityType<? extends LightningBolt> type, Level world) {
+         super(type, world);
+@@ -87,7 +88,7 @@ public class LightningBolt extends Entity {
+     @Override
+     public void tick() {
+         super.tick();
+-        if (this.life == 2) {
++        if (!this.isEffect && this.life == 2) { // Paper - Properly handle lightning effects api
+             if (this.level().isClientSide()) {
+                 this.level().playLocalSound(this.getX(), this.getY(), this.getZ(), SoundEvents.LIGHTNING_BOLT_THUNDER, SoundSource.WEATHER, 10000.0F, 0.8F + this.random.nextFloat() * 0.2F, false);
+                 this.level().playLocalSound(this.getX(), this.getY(), this.getZ(), SoundEvents.LIGHTNING_BOLT_IMPACT, SoundSource.WEATHER, 2.0F, 0.5F + this.random.nextFloat() * 0.2F, false);
+@@ -134,7 +135,7 @@ public class LightningBolt extends Entity {
+             }
+         }
+ 
+-        if (this.life >= 0 && !this.visualOnly) { // CraftBukkit - add !this.visualOnly
++        if (this.life >= 0 && !this.isEffect) { // CraftBukkit - add !this.visualOnly // Paper - Properly handle lightning effects api
+             if (!(this.level() instanceof ServerLevel)) {
+                 this.level().setSkyFlashTime(2);
+             } else if (!this.visualOnly) {
+@@ -163,7 +164,7 @@ public class LightningBolt extends Entity {
+     }
+ 
+     private void spawnFire(int spreadAttempts) {
+-        if (!this.visualOnly && !this.level().isClientSide && this.level().getGameRules().getBoolean(GameRules.RULE_DOFIRETICK)) {
++        if (!this.visualOnly && !this.isEffect && !this.level().isClientSide && this.level().getGameRules().getBoolean(GameRules.RULE_DOFIRETICK)) { // Paper - Properly handle lightning effects api
+             BlockPos blockposition = this.blockPosition();
+             BlockState iblockdata = BaseFireBlock.getState(this.level(), blockposition);
+ 
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+index 166458785b507208caa7ecf8ee8b60650ca3523a..7200c336de27ffd4d37231768ff5192956ede972 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+@@ -736,7 +736,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
+ 
+         LightningBolt lightning = EntityType.LIGHTNING_BOLT.create(this.world);
+         lightning.moveTo(loc.getX(), loc.getY(), loc.getZ());
+-        lightning.setVisualOnly(isVisual);
++        lightning.isEffect = isVisual; // Paper - Properly handle lightning effects api
+         this.world.strikeLightning(lightning, LightningStrikeEvent.Cause.CUSTOM);
+         return (LightningStrike) lightning.getBukkitEntity();
+     }
+diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftLightningStrike.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftLightningStrike.java
+index 6fed8075aa75e3852dc826a45ca44603c0446a56..e9f471e60af0725ec34e2985d63ae9ea9f88590a 100644
+--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftLightningStrike.java
++++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftLightningStrike.java
+@@ -13,7 +13,7 @@ public class CraftLightningStrike extends CraftEntity implements LightningStrike
+ 
+     @Override
+     public boolean isEffect() {
+-        return this.getHandle().visualOnly;
++        return this.getHandle().isEffect; // Paper - Properly handle lightning effects api
+     }
+ 
+     public int getFlashes() {