From 89d18f929ffdd31d7da0cedb24e120bd33170355 Mon Sep 17 00:00:00 2001
From: "Dylan K. Taylor" <dktapps@pmmp.io>
Date: Wed, 6 Aug 2025 15:48:29 +0100
Subject: [PATCH] RakLibServer: fixed deadlock on thread crash

synchronized block -> getCrashInfo -> join -> synchronized on the same
context on the child thread -> deadlock

instead we check for isTerminated and then get the crash info outside
of the synchronized block.
---
 src/network/mcpe/raklib/RakLibServer.php | 16 ++++++++--------
 src/thread/CommonThreadPartsTrait.php    |  2 ++
 2 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/network/mcpe/raklib/RakLibServer.php b/src/network/mcpe/raklib/RakLibServer.php
index d5e825bee..f66734ee5 100644
--- a/src/network/mcpe/raklib/RakLibServer.php
+++ b/src/network/mcpe/raklib/RakLibServer.php
@@ -68,17 +68,17 @@ class RakLibServer extends Thread{
 	public function startAndWait(int $options = NativeThread::INHERIT_NONE) : void{
 		$this->start($options);
 		$this->synchronized(function() : void{
-			while(!$this->ready && $this->getCrashInfo() === null){
+			while(!$this->ready && !$this->isTerminated()){
 				$this->wait();
 			}
-			$crashInfo = $this->getCrashInfo();
-			if($crashInfo !== null){
-				if($crashInfo->getType() === SocketException::class){
-					throw new SocketException($crashInfo->getMessage());
-				}
-				throw new ThreadCrashException("RakLib failed to start", $crashInfo);
-			}
 		});
+		$crashInfo = $this->getCrashInfo();
+		if($crashInfo !== null){
+			if($crashInfo->getType() === SocketException::class){
+				throw new SocketException($crashInfo->getMessage());
+			}
+			throw new ThreadCrashException("RakLib failed to start", $crashInfo);
+		}
 	}
 
 	protected function onRun() : void{
diff --git a/src/thread/CommonThreadPartsTrait.php b/src/thread/CommonThreadPartsTrait.php
index de606a7b2..d7d51d40f 100644
--- a/src/thread/CommonThreadPartsTrait.php
+++ b/src/thread/CommonThreadPartsTrait.php
@@ -100,6 +100,8 @@ trait CommonThreadPartsTrait{
 		//*before* the shutdown handler is invoked, so we might land here before the crash info has been set.
 		//In the future this should probably be fixed by running the shutdown handlers before setting isTerminated,
 		//but this workaround should be good enough for now.
+		//WARNING: Do not call this inside a synchronized block on this thread's context. Because the shutdown handler
+		//runs in a synchronized block, this will result in a deadlock.
 		if($this->isTerminated() && !$this->isJoined()){
 			$this->join();
 		}