Paper/patches/server/0484-Fix-Concurrency-issue-in-ShufflingList.patch
Jake Potrebic 9147456fc9
Updated Upstream (CraftBukkit/Spigot) (#8815)
Upstream has released updates that appear to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

CraftBukkit Changes:
ab8ace685 SPIGOT-7236: Bone meal doesn't increase use statistic
7dcb59b8e Avoid switch on material in previous commit

Spigot Changes:
19641c75 SPIGOT-7235: World.Spigot#strikeLightningEffect doesn't do anything
2023-01-27 12:52:04 -08:00

70 lines
3.6 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 6 Jul 2020 18:36:41 -0400
Subject: [PATCH] Fix Concurrency issue in ShufflingList
if multiple threads from worldgen sort at same time, it will crash.
So make a copy of the list for sorting purposes.
diff --git a/src/main/java/net/minecraft/world/entity/ai/behavior/GateBehavior.java b/src/main/java/net/minecraft/world/entity/ai/behavior/GateBehavior.java
index 419eadbe31b86b7192fd7a63268d547705e7c7ce..b45c4f50705f80163d44d9e588f86a5770f5be38 100644
--- a/src/main/java/net/minecraft/world/entity/ai/behavior/GateBehavior.java
+++ b/src/main/java/net/minecraft/world/entity/ai/behavior/GateBehavior.java
@@ -17,7 +17,7 @@ public class GateBehavior<E extends LivingEntity> implements BehaviorControl<E>
private final Set<MemoryModuleType<?>> exitErasedMemories;
private final GateBehavior.OrderPolicy orderPolicy;
private final GateBehavior.RunningPolicy runningPolicy;
- private final ShufflingList<BehaviorControl<? super E>> behaviors = new ShufflingList<>();
+ private final ShufflingList<BehaviorControl<? super E>> behaviors = new ShufflingList<>(false); // Paper - don't use a clone
private Behavior.Status status = Behavior.Status.STOPPED;
public GateBehavior(Map<MemoryModuleType<?>, MemoryStatus> requiredMemoryState, Set<MemoryModuleType<?>> memoriesToForgetWhenStopped, GateBehavior.OrderPolicy order, GateBehavior.RunningPolicy runMode, List<Pair<? extends BehaviorControl<? super E>, Integer>> tasks) {
diff --git a/src/main/java/net/minecraft/world/entity/ai/behavior/ShufflingList.java b/src/main/java/net/minecraft/world/entity/ai/behavior/ShufflingList.java
index 9fb20cd00568aeea25284ea0e80fe52cb1c3eede..731ef21dbbd25d6924717de42f4569a9b5935643 100644
--- a/src/main/java/net/minecraft/world/entity/ai/behavior/ShufflingList.java
+++ b/src/main/java/net/minecraft/world/entity/ai/behavior/ShufflingList.java
@@ -16,12 +16,25 @@ import net.minecraft.util.RandomSource;
public class ShufflingList<U> implements Iterable<U> {
protected final List<ShufflingList.WeightedEntry<U>> entries;
private final RandomSource random = RandomSource.create();
+ private final boolean isUnsafe; // Paper
public ShufflingList() {
+ // Paper start
+ this(true);
+ }
+ public ShufflingList(boolean isUnsafe) {
+ this.isUnsafe = isUnsafe;
+ // Paper end
this.entries = Lists.newArrayList();
}
private ShufflingList(List<ShufflingList.WeightedEntry<U>> list) {
+ // Paper start
+ this(list, true);
+ }
+ private ShufflingList(List<ShufflingList.WeightedEntry<U>> list, boolean isUnsafe) {
+ this.isUnsafe = isUnsafe;
+ // Paper end
this.entries = Lists.newArrayList(list);
}
@@ -37,11 +50,12 @@ public class ShufflingList<U> implements Iterable<U> {
}
public ShufflingList<U> shuffle() {
- this.entries.forEach((entry) -> {
- entry.setRandom(this.random.nextFloat());
- });
- this.entries.sort(Comparator.comparingDouble(ShufflingList.WeightedEntry::getRandWeight));
- return this;
+ // Paper start - make concurrent safe, work off a clone of the list
+ List<ShufflingList.WeightedEntry<U>> list = this.isUnsafe ? Lists.newArrayList(this.entries) : this.entries;
+ list.forEach(entry -> entry.setRandom(this.random.nextFloat()));
+ list.sort(Comparator.comparingDouble(ShufflingList.WeightedEntry::getRandWeight));
+ return this.isUnsafe ? new ShufflingList<>(list, this.isUnsafe) : this;
+ // Paper end
}
public Stream<U> stream() {