From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Aikar 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 a4f97c1df86c574af9b9824a38034a3d76d6e357..d65defd5fc54086a969c568b93dfb05f40dd5a44 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 implements Comparable> { 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 0b8d8b9875acf4c0a6bd47941ff57d01285dd507..3ad9f1327cd99e16e8eca86d72cb8a57f28b245e 100644 --- a/src/main/java/net/minecraft/commands/CommandSourceStack.java +++ b/src/main/java/net/minecraft/commands/CommandSourceStack.java @@ -55,7 +55,7 @@ public class CommandSourceStack implements SharedSuggestionProvider, com.destroy private final EntityAnchorArgument.Anchor anchor; private final Vec2 rotation; private final CommandSigningContext signingContext; - public volatile CommandNode currentCommand; // CraftBukkit + public java.util.Map currentCommand = new java.util.concurrent.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) -> { @@ -185,9 +185,11 @@ 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