From 193308e8db069bec82d2856cce908670e58ea31a 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 a7104e966..f2e96da81 100644 --- a/src/main/java/net/minecraft/server/PlayerConnection.java +++ b/src/main/java/net/minecraft/server/PlayerConnection.java @@ -1578,6 +1578,29 @@ public class PlayerConnection implements PacketListenerPlayIn { } if (!async && s.startsWith("/")) { + // Paper Start + if (!org.spigotmc.AsyncCatcher.shuttingDown && !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() == 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 d97cba9c0..a29b7b792 100644 --- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java +++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java @@ -704,6 +704,29 @@ public final class CraftServer implements Server { Validate.notNull(commandLine, "CommandLine cannot be null"); org.spigotmc.AsyncCatcher.catchOp( "command dispatch" ); // Spigot + // Paper Start + if (!org.spigotmc.AsyncCatcher.shuttingDown && !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; } diff --git a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java index ddef523ea..70f8d4299 100644 --- a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java +++ b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java @@ -13,6 +13,7 @@ public class ServerShutdownThread extends Thread { public void run() { try { org.spigotmc.AsyncCatcher.enabled = false; // Spigot + org.spigotmc.AsyncCatcher.shuttingDown = true; // Paper server.close(); } finally { try { diff --git a/src/main/java/org/spigotmc/AsyncCatcher.java b/src/main/java/org/spigotmc/AsyncCatcher.java index aeed76972..9f7d2ef93 100644 --- a/src/main/java/org/spigotmc/AsyncCatcher.java +++ b/src/main/java/org/spigotmc/AsyncCatcher.java @@ -6,6 +6,7 @@ public class AsyncCatcher { public static boolean enabled = true; + public static boolean shuttingDown = false; // Paper public static void catchOp(String reason) { diff --git a/src/main/java/org/spigotmc/RestartCommand.java b/src/main/java/org/spigotmc/RestartCommand.java index e7b953ca3..ccea803f5 100644 --- a/src/main/java/org/spigotmc/RestartCommand.java +++ b/src/main/java/org/spigotmc/RestartCommand.java @@ -43,6 +43,7 @@ public class RestartCommand extends Command private static void restart(final String restartScript) { AsyncCatcher.enabled = false; // Disable async catcher incase it interferes with us + org.spigotmc.AsyncCatcher.shuttingDown = true; // Paper try { String[] split = restartScript.split( " " ); -- 2.21.0