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 20a7cdf87f307878d66922aaac0c60cff218e46c..39844531b03eb8a6c70700b4ecbf0ff1a557424d 100644 --- a/src/main/java/com/mojang/brigadier/tree/CommandNode.java +++ b/src/main/java/com/mojang/brigadier/tree/CommandNode.java @@ -75,10 +75,10 @@ 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 efad6dc30ff2731fdaed9c7f8d974aba8d8a4bcf..24172c3b7b1d2faa13b18bedf89ad051267feb6c 100644 --- a/src/main/java/net/minecraft/commands/CommandSourceStack.java +++ b/src/main/java/net/minecraft/commands/CommandSourceStack.java @@ -61,7 +61,7 @@ public class CommandSourceStack implements SharedSuggestionProvider, com.destroy private final Vec2 rotation; private final CommandSigningContext signingContext; private final TaskChainer chatMessageChainer; - public volatile CommandNode currentCommand; // CraftBukkit + public java.util.Map currentCommand = new java.util.concurrent.ConcurrentHashMap<>(); // CraftBukkit // Paper public boolean bypassSelectorPermissions = false; // Paper public CommandSourceStack(CommandSource output, Vec3 pos, Vec2 rot, ServerLevel world, int level, String name, Component displayName, MinecraftServer server, @Nullable Entity entity) { @@ -194,9 +194,11 @@ 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