PaperMC/patches/server/0492-Thread-Safe-Vanilla-Command-permission-checking.patch

64 lines
3.5 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sat, 11 Jul 2020 03:54:28 -0400
Subject: [PATCH] Thread Safe Vanilla Command permission checking
Datapacks check this on load and are built concurrently. This was breaking them badly due
to race conditions.
Plus, .canUse we want to be safe for async anyways.
diff --git a/src/main/java/com/mojang/brigadier/tree/CommandNode.java b/src/main/java/com/mojang/brigadier/tree/CommandNode.java
index 2b87c6eb28d4db634dd6d8ee42ff3aa78ed7cb68..f64aa22ed6fcb4af67317b99f459ee5296392548 100644
--- a/src/main/java/com/mojang/brigadier/tree/CommandNode.java
+++ b/src/main/java/com/mojang/brigadier/tree/CommandNode.java
@@ -74,10 +74,10 @@ public abstract class CommandNode<S> implements Comparable<CommandNode<S>> {
public synchronized boolean canUse(final S source) {
if (source instanceof CommandSourceStack) {
try {
- ((CommandSourceStack) source).currentCommand = this;
+ ((CommandSourceStack) source).currentCommand.put(Thread.currentThread(), this); // Paper
return this.requirement.test(source);
} finally {
- ((CommandSourceStack) source).currentCommand = null;
+ ((CommandSourceStack) source).currentCommand.remove(Thread.currentThread()); // Paper
}
}
// CraftBukkit end
diff --git a/src/main/java/net/minecraft/commands/CommandSourceStack.java b/src/main/java/net/minecraft/commands/CommandSourceStack.java
index a59d14e61fcbca7861a5593d0717b81262ccbdc5..71e29d29ed5c2d61832e2f124967bb223708406f 100644
--- a/src/main/java/net/minecraft/commands/CommandSourceStack.java
+++ b/src/main/java/net/minecraft/commands/CommandSourceStack.java
@@ -9,8 +9,10 @@ import com.mojang.brigadier.suggestion.Suggestions;
import com.mojang.brigadier.suggestion.SuggestionsBuilder;
import java.util.Collection;
import java.util.Iterator;
+import java.util.Map;
import java.util.Set;
import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentHashMap;
import java.util.function.BinaryOperator;
import java.util.stream.Stream;
import javax.annotation.Nullable;
@@ -54,7 +56,7 @@ public class CommandSourceStack implements SharedSuggestionProvider, com.destroy
private final ResultConsumer<CommandSourceStack> consumer;
private final EntityAnchorArgument.Anchor anchor;
private final Vec2 rotation;
- public volatile CommandNode currentCommand; // CraftBukkit
+ public Map<Thread, CommandNode> currentCommand = new ConcurrentHashMap<>(); // CraftBukkit // Paper
public CommandSourceStack(CommandSource output, Vec3 pos, Vec2 rot, ServerLevel world, int level, String name, Component displayName, MinecraftServer server, @Nullable Entity entity) {
this(output, pos, rot, world, level, name, displayName, server, entity, false, (commandcontext, flag, j) -> {
@@ -175,9 +177,11 @@ public class CommandSourceStack implements SharedSuggestionProvider, com.destroy
@Override
public boolean hasPermission(int level) {
// CraftBukkit start
- CommandNode currentCommand = this.currentCommand;
+ // Paper start - fix concurrency issue
+ CommandNode currentCommand = this.currentCommand.get(Thread.currentThread());
if (currentCommand != null) {
return this.hasPermission(level, org.bukkit.craftbukkit.command.VanillaCommandWrapper.getPermission(currentCommand));
+ // Paper end
}
// CraftBukkit end