PaperMC/Spigot-Server-Patches/0048-Ensure-commands-are-not-ran-async.patch
Aikar a64aa09862
Ignore AsyncCatcher setting for Command Dispatch, always force sync
Plugins were abusing this to dispatch commands async anyways.

We will no longer check that flag, and force all commands to be ran sync.

Use a different boolean for allowing things go to through on shutdown/restart instead.

Resolves #1004
Resolves #1005
2018-02-15 00:34:58 -05:00

122 lines
6.1 KiB
Diff

From 09e8ebb6054e3f37de7d78ab784147cbf62985d4 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
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 da25a8bea..48379f414 100644
--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
@@ -1311,6 +1311,29 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
}
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() == 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 bfddd1685..462ad1024 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -645,6 +645,29 @@ public final class CraftServer implements Server {
Validate.notNull(sender, "Sender cannot be null");
Validate.notNull(commandLine, "CommandLine cannot be null");
+ // 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<Boolean> wait = new org.bukkit.craftbukkit.util.Waitable<Boolean>() {
+ @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 a0cdd2317..984df4083 100644
--- a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
@@ -14,6 +14,7 @@ public class ServerShutdownThread extends Thread {
public void run() {
try {
org.spigotmc.AsyncCatcher.enabled = false; // Spigot
+ org.spigotmc.AsyncCatcher.shuttingDown = true; // Paper
server.stop();
} catch (ExceptionWorldConflict ex) {
ex.printStackTrace();
diff --git a/src/main/java/org/spigotmc/AsyncCatcher.java b/src/main/java/org/spigotmc/AsyncCatcher.java
index 4b3aa85c9..e44c23016 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 49768734d..947c43a5d 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
public static void restart(final File script)
{
AsyncCatcher.enabled = false; // Disable async catcher incase it interferes with us
+ org.spigotmc.AsyncCatcher.shuttingDown = true; // Paper
try
{
if ( script.isFile() )
--
2.16.1