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 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 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 530a09fa3c9155459c6a4519e3412408ae658145..cb0045fc4ddd738c45dee89d57b213a633b9a136 100644 --- a/src/main/java/net/minecraft/commands/CommandSourceStack.java +++ b/src/main/java/net/minecraft/commands/CommandSourceStack.java @@ -56,7 +56,7 @@ public class CommandSourceStack implements SharedSuggestionProvider, com.destroy private final ResultConsumer consumer; private final EntityAnchorArgument.Anchor anchor; private final Vec2 rotation; - 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) -> { @@ -177,9 +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