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From 8611dc3d7c2d3cdc9187a2121c5805bc22b123e0 Mon Sep 17 00:00:00 2001
2016-01-13 06:00:58 +01:00
From: Aikar <aikar@aikar.co>
2016-03-01 00:09:49 +01:00
Date: Thu, 3 Mar 2016 01:17:12 -0600
2016-01-13 06:00:58 +01:00
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
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index 914366afc..5e8739462 100644
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--- a/src/main/java/net/minecraft/server/PlayerConnection.java
+++ b/src/main/java/net/minecraft/server/PlayerConnection.java
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@@ -1570,6 +1570,29 @@ public class PlayerConnection implements PacketListenerPlayIn {
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}
if (!async && s.startsWith("/")) {
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+ // Paper Start
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+ if (!org.spigotmc.AsyncCatcher.shuttingDown && !org.bukkit.Bukkit.isPrimaryThread()) {
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+ 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());
+ }
+ }
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+ // Paper End
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this.handleCommand(s);
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} else if (this.player.getChatFlags() == EnumChatVisibility.SYSTEM) {
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// 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
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index e3939387e..f7c29e372 100644
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--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
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@@ -720,6 +720,29 @@ public final class CraftServer implements Server {
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Validate.notNull(commandLine, "CommandLine cannot be null");
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org.spigotmc.AsyncCatcher.catchOp("command dispatch"); // Spigot
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+ // Paper Start
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+ if (!org.spigotmc.AsyncCatcher.shuttingDown && !Bukkit.isPrimaryThread()) {
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+ 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());
+ }
+ }
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+ // Paper End
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+
if (commandMap.dispatch(sender, commandLine)) {
return true;
}
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diff --git a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
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index ddef523ea..70f8d4299 100644
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--- a/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
+++ b/src/main/java/org/bukkit/craftbukkit/util/ServerShutdownThread.java
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@@ -13,6 +13,7 @@ public class ServerShutdownThread extends Thread {
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public void run() {
try {
org.spigotmc.AsyncCatcher.enabled = false; // Spigot
+ org.spigotmc.AsyncCatcher.shuttingDown = true; // Paper
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server.close();
} finally {
try {
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diff --git a/src/main/java/org/spigotmc/AsyncCatcher.java b/src/main/java/org/spigotmc/AsyncCatcher.java
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index aeed76972..9f7d2ef93 100644
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--- 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
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index e7b953ca3..ccea803f5 100644
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--- 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
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private static void restart(final String restartScript)
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{
AsyncCatcher.enabled = false; // Disable async catcher incase it interferes with us
+ org.spigotmc.AsyncCatcher.shuttingDown = true; // Paper
try
{
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String[] split = restartScript.split( " " );
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--
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2.25.0
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