- Make sure a hung worker thread always crashes the application

src/swrenderer/drawers/r_thread.cpp

@@ -33,6 +33,11 @@
 #include "r_thread.h"
 #include "swrenderer/r_memory.h"
 #include "swrenderer/r_renderthread.h"
+#include <chrono>
+
+#ifdef WIN32
+void PeekThreadedErrorPane();
+#endif
 
 CVAR(Bool, r_multithreaded, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG);
 
@@ -73,10 +78,20 @@ void DrawerThreads::Execute(DrawerCommandQueuePtr commands)
 
 void DrawerThreads::WaitForWorkers()
 {
+	using namespace std::chrono_literals;
+
 	// Wait for workers to finish
 	auto queue = Instance();
 	std::unique_lock<std::mutex> end_lock(queue->end_mutex);
-	queue->end_condition.wait(end_lock, [&]() { return queue->tasks_left == 0; });
+	if (!queue->end_condition.wait_for(end_lock, 5s, [&]() { return queue->tasks_left == 0; }))
+	{
+#ifdef WIN32
+		PeekThreadedErrorPane();
+#endif
+		// Invoke the crash reporter so that we can capture the call stack of whatever the hung worker thread is doing
+		int *threadCrashed = nullptr;
+		*threadCrashed = 0xdeadbeef;
+	}
 	end_lock.unlock();
 
 	// Clean up

src/swrenderer/scene/r_scene.cpp

@@ -57,6 +57,11 @@
 #include "swrenderer/r_memory.h"
 #include "swrenderer/r_renderthread.h"
 #include "swrenderer/things/r_playersprite.h"
+#include <chrono>
+
+#ifdef WIN32
+void PeekThreadedErrorPane();
+#endif
 
 EXTERN_CVAR(Bool, r_shadercolormaps)
 EXTERN_CVAR(Int, r_clearbuffer)
@@ -217,9 +222,18 @@ namespace swrenderer
 		// Wait for everyone to finish:
 		if (Threads.size() > 1)
 		{
+			using namespace std::chrono_literals;
 			std::unique_lock<std::mutex> end_lock(end_mutex);
 			finished_threads++;
-			end_condition.wait(end_lock, [&]() { return finished_threads == Threads.size(); });
+			if (!end_condition.wait_for(end_lock, 5s, [&]() { return finished_threads == Threads.size(); }))
+			{
+#ifdef WIN32
+				PeekThreadedErrorPane();
+#endif
+				// Invoke the crash reporter so that we can capture the call stack of whatever the hung worker thread is doing
+				int *threadCrashed = nullptr;
+				*threadCrashed = 0xdeadbeef;
+			}
 			finished_threads = 0;
 		}
 

src/win32/i_main.cpp

@@ -821,6 +821,13 @@ void ShowErrorPane(const char *text)
 	}
 }
 
+void PeekThreadedErrorPane()
+{
+	// Allow SendMessage from another thread to call its message handler so that it can display the crash dialog
+	MSG msg;
+	PeekMessage(&msg, 0, 0, 0, PM_NOREMOVE);
+}
+
 //==========================================================================
 //
 // DoMain