From 49a93c12b64029ade8efbe041717bfd6505976db Mon Sep 17 00:00:00 2001 From: Aikar Date: Thu, 3 Mar 2016 01:17:12 -0600 Subject: [PATCH] Ensure commands are not ran async Plugins calling Player.chat("/foo") or Server.dispatchCommand() could trigger the server to execute a command while on another thread. These commands would then process EXPECTING to be on the main thread, leaving to very hard to trace concurrency issues. This change will synchronize the command execution back to the main thread, causing a big slowdown in execution but throwing an exception at same time to raise awareness that it is happening so that plugin authors can fix their code to stop executing commands async. diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java index 0c2c151..2cde490 100644 --- a/src/main/java/net/minecraft/server/PlayerConnection.java +++ b/src/main/java/net/minecraft/server/PlayerConnection.java @@ -1264,6 +1264,29 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable { } if (!async && s.startsWith("/")) { + // Paper Start + if (!org.bukkit.Bukkit.isPrimaryThread()) { + final String fCommandLine = s; + MinecraftServer.LOGGER.log(org.apache.logging.log4j.Level.ERROR, "Command Dispatched Async: " + fCommandLine); + MinecraftServer.LOGGER.log(org.apache.logging.log4j.Level.ERROR, "Please notify author of plugin causing this execution to fix this bug! see: http://bit.ly/1oSiM6C", new Throwable()); + Waitable wait = new Waitable() { + @Override + protected Object evaluate() { + chat(fCommandLine, false); + return null; + } + }; + minecraftServer.processQueue.add(wait); + try { + wait.get(); + return; + } catch (InterruptedException e) { + Thread.currentThread().interrupt(); // This is proper habit for java. If we aren't handling it, pass it on! + } catch (Exception e) { + throw new RuntimeException("Exception processing chat command", e.getCause()); + } + } + // Paper End this.handleCommand(s); } else if (this.player.getChatFlags() == EntityHuman.EnumChatVisibility.SYSTEM) { // Do nothing, this is coming from a plugin diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java index 14e5647..c6cee80 100644 --- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java +++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java @@ -642,6 +642,29 @@ public final class CraftServer implements Server { Validate.notNull(sender, "Sender cannot be null"); Validate.notNull(commandLine, "CommandLine cannot be null"); + // Paper Start + if (!Bukkit.isPrimaryThread()) { + final CommandSender fSender = sender; + final String fCommandLine = commandLine; + Bukkit.getLogger().log(Level.SEVERE, "Command Dispatched Async: " + commandLine); + Bukkit.getLogger().log(Level.SEVERE, "Please notify author of plugin causing this execution to fix this bug! see: http://bit.ly/1oSiM6C", new Throwable()); + org.bukkit.craftbukkit.util.Waitable wait = new org.bukkit.craftbukkit.util.Waitable() { + @Override + protected Boolean evaluate() { + return dispatchCommand(fSender, fCommandLine); + } + }; + net.minecraft.server.MinecraftServer.getServer().processQueue.add(wait); + try { + return wait.get(); + } catch (InterruptedException e) { + Thread.currentThread().interrupt(); // This is proper habit for java. If we aren't handling it, pass it on! + } catch (Exception e) { + throw new RuntimeException("Exception processing dispatch command", e.getCause()); + } + } + // Paper End + if (commandMap.dispatch(sender, commandLine)) { return true; } -- 2.8.2