From b4d03501aff8b7ff8318f562a00a6ef89adb9eb1 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Sun, 3 Oct 2021 14:01:27 +0200
Subject: [PATCH] - be a bit more aggressive with the GC when not running the
 game loop.

Since most CheckGC calls are within the main game ticker, the engine can accumulate a lot of data when creating/deleting objects in the menu or other UI parts and never manage to collect everything
---
 src/common/objects/dobject.cpp |  3 +++
 src/common/objects/dobjgc.cpp  |  1 +
 src/common/objects/dobjgc.h    | 10 +++++++++-
 src/g_game.cpp                 |  9 +++++++++
 4 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/common/objects/dobject.cpp b/src/common/objects/dobject.cpp
index 9f4a164e4..8516229de 100644
--- a/src/common/objects/dobject.cpp
+++ b/src/common/objects/dobject.cpp
@@ -229,6 +229,7 @@ DObject::DObject ()
 	ObjNext = GC::Root;
 	GCNext = nullptr;
 	GC::Root = this;
+	GC::AllocCount++;
 }
 
 DObject::DObject (PClass *inClass)
@@ -238,6 +239,7 @@ DObject::DObject (PClass *inClass)
 	ObjNext = GC::Root;
 	GCNext = nullptr;
 	GC::Root = this;
+	GC::AllocCount++;
 }
 
 //==========================================================================
@@ -275,6 +277,7 @@ DObject::~DObject ()
 
 void DObject::Release()
 {
+	if (GC::AllocCount > 0) GC::AllocCount--;
 	DObject **probe;
 
 	// Unlink this object from the GC list.
diff --git a/src/common/objects/dobjgc.cpp b/src/common/objects/dobjgc.cpp
index 9afa0b0af..58b27c4b7 100644
--- a/src/common/objects/dobjgc.cpp
+++ b/src/common/objects/dobjgc.cpp
@@ -108,6 +108,7 @@ namespace GC
 size_t AllocBytes;
 size_t Threshold;
 size_t Estimate;
+size_t AllocCount;
 DObject *Gray;
 DObject *Root;
 DObject *SoftRoots;
diff --git a/src/common/objects/dobjgc.h b/src/common/objects/dobjgc.h
index e3f8b85b1..d01e52cf6 100644
--- a/src/common/objects/dobjgc.h
+++ b/src/common/objects/dobjgc.h
@@ -43,6 +43,9 @@ namespace GC
 	// Number of bytes currently allocated through M_Malloc/M_Realloc.
 	extern size_t AllocBytes;
 
+	// Number of allocated objects since last CheckGC call.
+	extern size_t AllocCount;
+
 	// Amount of memory to allocate before triggering a collection.
 	extern size_t Threshold;
 
@@ -105,10 +108,15 @@ namespace GC
 	}
 
 	// Check if it's time to collect, and do a collection step if it is.
-	static inline void CheckGC()
+	static inline bool CheckGC()
 	{
+		AllocCount = 0;
 		if (AllocBytes >= Threshold)
+		{
 			Step();
+			return true;
+		}
+		return false;
 	}
 
 	// Forces a collection to start now.
diff --git a/src/g_game.cpp b/src/g_game.cpp
index fdbc18aa8..f394d1a85 100644
--- a/src/g_game.cpp
+++ b/src/g_game.cpp
@@ -1316,6 +1316,15 @@ void G_Ticker ()
 	default:
 		break;
 	}
+	// Do some more aggressive GC maintenance when the game ticker is inactive. 
+	if ((gamestate != GS_LEVEL && gamestate != GS_TITLELEVEL) || paused || P_CheckTickerPaused())
+	{
+		size_t ac = std::max<size_t>(10, GC::AllocCount);
+		for (size_t i = 0; i < ac; i++)
+		{
+			if (!GC::CheckGC()) break;
+		}
+	}
 
 	// [MK] Additional ticker for UI events right after all others
 	primaryLevel->localEventManager->PostUiTick();