From 734f09abe6422237bbe8078cb8365d385a22e93d Mon Sep 17 00:00:00 2001
From: Petr Mikheev <ptmikheev@gmail.com>
Date: Sat, 3 Dec 2022 16:56:23 +0100
Subject: [PATCH] Run Lua GC in every frame

---
 apps/openmw/mwlua/luamanagerimp.cpp            |  4 ++++
 docs/source/reference/modding/settings/lua.rst | 12 ++++++++++++
 files/settings-default.cfg                     |  3 +++
 3 files changed, 19 insertions(+)

diff --git a/apps/openmw/mwlua/luamanagerimp.cpp b/apps/openmw/mwlua/luamanagerimp.cpp
index 862deb0d3a..d98bb557b4 100644
--- a/apps/openmw/mwlua/luamanagerimp.cpp
+++ b/apps/openmw/mwlua/luamanagerimp.cpp
@@ -131,6 +131,10 @@ namespace MWLua
     void LuaManager::update()
     {
         static const bool luaDebug = Settings::Manager::getBool("lua debug", "Lua");
+        static const int gcStepCount = Settings::Manager::getInt("gc steps per frame", "Lua");
+        if (gcStepCount > 0)
+            lua_gc(mLua.sol(), LUA_GCSTEP, gcStepCount);
+
         if (mPlayer.isEmpty())
             return;  // The game is not started yet.
 
diff --git a/docs/source/reference/modding/settings/lua.rst b/docs/source/reference/modding/settings/lua.rst
index 4433067952..510f59dc5d 100644
--- a/docs/source/reference/modding/settings/lua.rst
+++ b/docs/source/reference/modding/settings/lua.rst
@@ -26,3 +26,15 @@ If one, a separate thread is used.
 Values >1 are not yet supported.
 
 This setting can only be configured by editing the settings configuration file.
+
+gc steps per frame
+------------------
+
+:Type:		integer
+:Range:		>= 0
+:Default:	100
+
+Lua garbage collector steps per frame. The higher the value the more time Lua runtime can spend on freeing unused memory.
+
+This setting can only be configured by editing the settings configuration file.
+
diff --git a/files/settings-default.cfg b/files/settings-default.cfg
index 8a6fc40fd7..779739eae5 100644
--- a/files/settings-default.cfg
+++ b/files/settings-default.cfg
@@ -1141,6 +1141,9 @@ lua debug = false
 # If zero, Lua scripts are processed in the main thread.
 lua num threads = 1
 
+# Lua garbage collector steps per frame.
+gc steps per frame = 100
+
 [Stereo]
 # Enable/disable stereo view. This setting is ignored in VR.
 stereo enabled = false