From 35f5ba8bb9297d06b7d8238295ae3601367d91ad Mon Sep 17 00:00:00 2001
From: sharkautarch <128002472+sharkautarch@users.noreply.github.com>
Date: Fri, 24 May 2024 15:43:09 -0400
Subject: [PATCH 1/2] sdlwindow.cpp: close m_thread w/o std::terminate being
 called

---
 src/Backends/SDLBackend.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/Backends/SDLBackend.cpp b/src/Backends/SDLBackend.cpp
index d7456b6a4..5420683a3 100644
--- a/src/Backends/SDLBackend.cpp
+++ b/src/Backends/SDLBackend.cpp
@@ -53,6 +53,7 @@ namespace gamescope
 		GAMESCOPE_SDL_EVENT_CURSOR,
 
 		GAMESCOPE_SDL_EVENT_COUNT,
+		GAMESCOPE_SDL_EVENT_REQ_EXIT,
 	};
 
 	class CSDLConnector final : public IBackendConnector
@@ -111,6 +112,7 @@ namespace gamescope
 	{
 	public:
 		CSDLBackend();
+		~CSDLBackend();
 
 		/////////////
 		// IBackend
@@ -548,7 +550,12 @@ namespace gamescope
 	{
 		// Do nothing.
 	}
-
+	
+	CSDLBackend::~CSDLBackend() {
+		PushUserEvent(GAMESCOPE_SDL_EVENT_REQ_EXIT);
+		m_SDLThread.join();
+	}
+	
 	void CSDLBackend::SDLThreadFunc()
 	{
 		pthread_setname_np( pthread_self(), "gamescope-sdl" );
@@ -944,6 +951,9 @@ namespace gamescope
 
 						SDL_SetCursor( m_pCursor );
 					}
+					else if ( event.type == GetUserEventIndex( GAMESCOPE_SDL_EVENT_REQ_EXIT ) ) {
+						return;
+					}
 				}
 				break;
 			}

From 61392a9e545e0a3341c0d510aaa453c08826cc5b Mon Sep 17 00:00:00 2001
From: sharkautarch <128002472+sharkautarch@users.noreply.github.com>
Date: Thu, 30 May 2024 14:02:00 -0400
Subject: [PATCH 2/2] steamcompmgr, rendervulkan: prevent segfault that occured
 when closing gamescope, due to a race condition between present thread @
 present_wait_thread_func & compositor thread @ steamcompmgr_exit

---
 src/rendervulkan.cpp | 7 ++++++-
 src/rendervulkan.hpp | 4 ++++
 src/steamcompmgr.cpp | 8 ++++++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/rendervulkan.cpp b/src/rendervulkan.cpp
index ffd0783da..094141839 100644
--- a/src/rendervulkan.cpp
+++ b/src/rendervulkan.cpp
@@ -2669,7 +2669,8 @@ bool acquire_next_image( void )
 }
 
 
-static std::atomic<uint64_t> g_currentPresentWaitId = {0u};
+inline std::atomic<uint64_t> g_currentPresentWaitId = {0u};
+inline std::atomic<bool> g_presentThreadShouldExit = {false};
 static std::mutex present_wait_lock;
 
 extern void mangoapp_output_update( uint64_t vblanktime );
@@ -2693,6 +2694,10 @@ static void present_wait_thread_func( void )
 				uint64_t vblanktime = get_time_in_nanos();
 				GetVBlankTimer().MarkVBlank( vblanktime, true );
 				mangoapp_output_update( vblanktime );
+			} else if ( g_presentThreadShouldExit.load(std::memory_order_acquire)) {
+				g_presentThreadShouldExit = 0;
+				g_presentThreadShouldExit.notify_all();
+				return;
 			}
 		}
 	}
diff --git a/src/rendervulkan.hpp b/src/rendervulkan.hpp
index 177468228..a2e0dd972 100644
--- a/src/rendervulkan.hpp
+++ b/src/rendervulkan.hpp
@@ -74,6 +74,10 @@ enum EStreamColorspace : int
 #include <vulkan/vulkan.h>
 #include <drm_fourcc.h>
 
+extern std::atomic<uint64_t> g_currentPresentWaitId;
+
+extern std::atomic<bool> g_presentThreadShouldExit;
+
 struct VulkanRenderer_t
 {
 	struct wlr_renderer base;
diff --git a/src/steamcompmgr.cpp b/src/steamcompmgr.cpp
index 910ed3912..f6539829e 100644
--- a/src/steamcompmgr.cpp
+++ b/src/steamcompmgr.cpp
@@ -5840,6 +5840,14 @@ steamcompmgr_exit(void)
 		}
 	}
 
+    //request the present_wait thread to exit
+    //needed to avoid getting a segfault at exit due to race condition:
+    g_presentThreadShouldExit.store(true, std::memory_order_release);
+    g_currentPresentWaitId = 0; //present thread will check if it should exit if this is zero
+    g_currentPresentWaitId.notify_all();
+    g_presentThreadShouldExit.wait(true); //present thread will toggle this atomic when it sees the exit request
+                                          //this allows us to wait for present thread to close before deleting the backend
+
     gamescope::IBackend::Set( nullptr );
 
     wlserver_lock();