From b2a0ca3515d4c27f97197757010785a5815e7fe4 Mon Sep 17 00:00:00 2001
From: cosmonaut <evan@moonside.games>
Date: Mon, 20 Nov 2023 15:18:06 -0800
Subject: [PATCH] replace WeakReference with weak GCHandle

---
 src/Graphics/GraphicsDevice.cs   | 14 ++++++++------
 src/Graphics/GraphicsResource.cs | 12 ++++++------
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/Graphics/GraphicsDevice.cs b/src/Graphics/GraphicsDevice.cs
index 3d3a7e1..c44ded3 100644
--- a/src/Graphics/GraphicsDevice.cs
+++ b/src/Graphics/GraphicsDevice.cs
@@ -2,6 +2,7 @@
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.InteropServices;
 using RefreshCS;
 
 namespace MoonWorks.Graphics
@@ -22,7 +23,7 @@ namespace MoonWorks.Graphics
 
 		public bool IsDisposed { get; private set; }
 
-		private readonly HashSet<WeakReference<GraphicsResource>> resources = new HashSet<WeakReference<GraphicsResource>>();
+		private readonly HashSet<GCHandle> resources = new HashSet<GCHandle>();
 		private FencePool FencePool;
 
 		internal GraphicsDevice(
@@ -338,7 +339,7 @@ namespace MoonWorks.Graphics
 			return (TextureFormat) Refresh.Refresh_GetSwapchainFormat(Handle, window.Handle);
 		}
 
-		internal void AddResourceReference(WeakReference<GraphicsResource> resourceReference)
+		internal void AddResourceReference(GCHandle resourceReference)
 		{
 			lock (resources)
 			{
@@ -346,7 +347,7 @@ namespace MoonWorks.Graphics
 			}
 		}
 
-		internal void RemoveResourceReference(WeakReference<GraphicsResource> resourceReference)
+		internal void RemoveResourceReference(GCHandle resourceReference)
 		{
 			lock (resources)
 			{
@@ -377,11 +378,12 @@ namespace MoonWorks.Graphics
 				{
 					lock (resources)
 					{
-						foreach (var weakReference in resources)
+						foreach (var resource in resources)
 						{
-							if (weakReference.TryGetTarget(out var target))
+							var target = resource.Target;
+							if (target is IDisposable disposable)
 							{
-								target.Dispose();
+								disposable.Dispose();
 							}
 						}
 						resources.Clear();
diff --git a/src/Graphics/GraphicsResource.cs b/src/Graphics/GraphicsResource.cs
index c610df2..dc4a451 100644
--- a/src/Graphics/GraphicsResource.cs
+++ b/src/Graphics/GraphicsResource.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Runtime.InteropServices;
 
 namespace MoonWorks.Graphics
 {
@@ -10,14 +11,14 @@ namespace MoonWorks.Graphics
 		public bool IsDisposed { get; private set; }
 		protected abstract Action<IntPtr, IntPtr> QueueDestroyFunction { get; }
 
-		internal WeakReference<GraphicsResource> weakReference;
+		internal GCHandle selfReference;
 
 		public GraphicsResource(GraphicsDevice device, bool trackResource = true)
 		{
 			Device = device;
 
-			weakReference = new WeakReference<GraphicsResource>(this);
-			Device.AddResourceReference(weakReference);
+			selfReference = GCHandle.Alloc(this, GCHandleType.Weak);
+			Device.AddResourceReference(selfReference);
 		}
 
 		internal GraphicsResourceDisposalHandle CreateDisposalHandle()
@@ -36,10 +37,9 @@ namespace MoonWorks.Graphics
 				if (Handle != IntPtr.Zero)
 				{
 					QueueDestroyFunction(Device.Handle, Handle);
-					Device.RemoveResourceReference(weakReference);
-					weakReference.SetTarget(null);
+					Device.RemoveResourceReference(selfReference);
+					selfReference.Free();
 
-					weakReference = null;
 					Handle = IntPtr.Zero;
 				}