Re-enabled multithreaded lua GC, it seems faster

Author: Causeless

Source/Managers/LuaMan.cpp

@@ -33,9 +33,12 @@ void LuaStateWrapper::Initialize() {
 	luabind::open(m_State);
 	tracy::LuaRegister(m_State);
 
-	// Disable gc. We do this manually, so we can thread it to occur parallel with non-lua updates
-	// Not doing this for now... see StartAsyncGarbageCollection()
-	// lua_gc(m_State, LUA_GCSTOP, 0);
+	if (!g_SettingsMan.LuaMultithreadedGarbageCollectionDisabled())
+	{
+		// Disable gc. We do this manually, so we can thread it to occur parallel with non-lua updates
+		// See LuaMan::StartAsyncGarbageCollection()
+		lua_gc(m_State, LUA_GCSTOP, 0);
+	}
 
 	const luaL_Reg libsToLoad[] = {
 	    // Basic Lua libraries
@@ -1279,10 +1282,10 @@ void LuaMan::Update() {
 void LuaMan::StartAsyncGarbageCollection() {
 	ZoneScoped;
 
-	// For now we're not doing this... because it's slower than normal (blocking) GC collection during the update
-	// This is because Lua is trash and basically GCSTEP is meaningless and can cause memory leak runaway, whereas GCCOLLECT is ultra-expensive
-	// So for now we do normal GC collection :(
-	return;
+	if (g_SettingsMan.LuaMultithreadedGarbageCollectionDisabled())
+	{
+		return;
+	}
 
 	std::vector<LuaStateWrapper*> allStates;
 	allStates.reserve(m_ScriptStates.size() + 1);
@@ -1298,7 +1301,7 @@ void LuaMan::StartAsyncGarbageCollection() {
 		    g_ThreadMan.GetPriorityThreadPool().submit([luaState]() {
 			    ZoneScopedN("Lua Garbage Collection");
 			    std::lock_guard<std::recursive_mutex> lock(luaState->GetMutex());
-			    lua_gc(luaState->GetLuaState(), LUA_GCCOLLECT, 0); // we'd use GCSTEP but fuck lua it's trash
+			    lua_gc(luaState->GetLuaState(), LUA_GCCOLLECT, 0);
 			    lua_gc(luaState->GetLuaState(), LUA_GCSTOP, 0);
 		    }));
 	}

Source/Managers/SettingsMan.cpp

@@ -49,9 +49,9 @@ void SettingsMan::Clear() {
 	m_DisableFactionBuyMenuThemeCursors = false;
 	m_PathFinderGridNodeSize = SCENEGRIDSIZE;
 	m_AIUpdateInterval = 2;
-
 	m_NumberOfLuaStatesOverride = -1;
 	m_ForceImmediatePathingRequestCompletion = false;
+	m_LuaMultithreadedGarbageCollectionDisabled = false;
 
 	m_SkipIntro = false;
 	m_ShowToolTips = true;
@@ -168,6 +168,7 @@ int SettingsMan::ReadProperty(const std::string_view& propName, Reader& reader)
 	MatchProperty("AIUpdateInterval", { reader >> m_AIUpdateInterval; });
 	MatchProperty("NumberOfLuaStatesOverride", { reader >> m_NumberOfLuaStatesOverride; });
 	MatchProperty("ForceImmediatePathingRequestCompletion", { reader >> m_ForceImmediatePathingRequestCompletion; });
+	MatchProperty("LuaMultithreadedGarbageCollectionDisabled", { reader >> m_LuaMultithreadedGarbageCollectionDisabled; });
 	MatchProperty("EnableParticleSettling", { reader >> g_MovableMan.m_SettlingEnabled; });
 	MatchProperty("EnableMOSubtraction", { reader >> g_MovableMan.m_MOSubtractionEnabled; });
 	MatchProperty("DeltaTime", { g_TimerMan.SetDeltaTimeSecs(std::stof(reader.ReadPropValue())); });
@@ -294,6 +295,7 @@ int SettingsMan::Save(Writer& writer) const {
 	writer.NewPropertyWithValue("PathFinderGridNodeSize", m_PathFinderGridNodeSize);
 	writer.NewPropertyWithValue("AIUpdateInterval", m_AIUpdateInterval);
 	writer.NewPropertyWithValue("NumberOfLuaStatesOverride", m_NumberOfLuaStatesOverride);
+	writer.NewPropertyWithValue("LuaMultithreadedGarbageCollectionDisabled", m_LuaMultithreadedGarbageCollectionDisabled);
 	writer.NewPropertyWithValue("ForceImmediatePathingRequestCompletion", m_ForceImmediatePathingRequestCompletion);
 	writer.NewPropertyWithValue("EnableParticleSettling", g_MovableMan.m_SettlingEnabled);
 	writer.NewPropertyWithValue("EnableMOSubtraction", g_MovableMan.m_MOSubtractionEnabled);

Source/Managers/SettingsMan.h

@@ -104,6 +104,10 @@ namespace RTE {
 		/// Gets whether pathing requests will be forced to immediately complete for the next frame, or if they can take multiple frames to calculate.
 		/// @return Whether pathing requests will be forced to immediately complete for the next frame
 		bool GetForceImmediatePathingRequestCompletion() const { return m_ForceImmediatePathingRequestCompletion; }
+
+		/// Gets whether Lua multithreaded garbage collection is disabled.
+		/// @return Whether Lua multithreaded garbage collection is disabled.
+		bool LuaMultithreadedGarbageCollectionDisabled() const { return m_LuaMultithreadedGarbageCollectionDisabled; }
 #pragma endregion
 
 #pragma region Gameplay Settings
@@ -398,6 +402,7 @@ namespace RTE {
 		int m_AIUpdateInterval; //!< How often actor's AI should be updated, i.e. every n simulation updates.
 		int m_NumberOfLuaStatesOverride; //!< Overrides how many threaded Lua states we'll use. -1 for no override, which defaults to the maximum number of concurrent hardware threads.
 		bool m_ForceImmediatePathingRequestCompletion; //!< Whether pathing requests will be forced to immediately complete for the next frame, or if they can take multiple frames to calculate.
+		bool m_LuaMultithreadedGarbageCollectionDisabled; //!< Whether Lua multithreaded garbage collection is disabled.
 
 		bool m_SkipIntro; //!< Whether to play the intro of the game or skip directly to the main menu.
 		bool m_ShowToolTips; //!< Whether ToolTips are enabled or not.