From f1e3c55ea3fbab43ae6268b1e2332048fd34b61f Mon Sep 17 00:00:00 2001
From: Petr Mikheev <ptmikheev@gmail.com>
Date: Sun, 19 Sep 2021 10:27:48 +0200
Subject: [PATCH] Fix deadlock in Lua worker thread (#6286)

---
 apps/openmw/engine.cpp | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/apps/openmw/engine.cpp b/apps/openmw/engine.cpp
index 772af3759e..bbe4f25f69 100644
--- a/apps/openmw/engine.cpp
+++ b/apps/openmw/engine.cpp
@@ -875,7 +875,14 @@ public:
     void join()
     {
         if (mThread)
+        {
+            {
+                std::lock_guard<std::mutex> lk(mMutex);
+                mJoinRequest = true;
+            }
+            mCV.notify_one();
             mThread->join();
+        }
     }
 
 private:
@@ -891,10 +898,12 @@ private:
 
     void threadBody()
     {
-        while (!mEngine->mViewer->done() && !mEngine->mEnvironment.getStateManager()->hasQuitRequest())
+        while (true)
         {
             std::unique_lock<std::mutex> lk(mMutex);
-            mCV.wait(lk, [&]{ return mUpdateRequest; });
+            mCV.wait(lk, [&]{ return mUpdateRequest || mJoinRequest; });
+            if (mJoinRequest)
+                break;
 
             update();
 
@@ -908,6 +917,7 @@ private:
     std::mutex mMutex;
     std::condition_variable mCV;
     bool mUpdateRequest = false;
+    bool mJoinRequest = false;
     double mDt = 0;
     bool mIsGuiMode = false;
     std::optional<std::thread> mThread;