Cache Harmony Delegates & Runtime Invoke

BepInEx.IL2CPP/Hook/IL2CPPDetourMethodPatcher.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
@@ -59,6 +59,8 @@ public unsafe class IL2CPPDetourMethodPatcher : MethodPatcher
     private static ModuleBuilder fixedStructModuleBuilder;
     private static readonly Dictionary<int, Type> FixedStructCache = new();
 
+    private static readonly Dictionary<object, object> DelegateCache = new();
+
     private bool isValid;
     private INativeMethodInfoStruct modifiedNativeMethodInfo;
 
@@ -140,8 +142,12 @@ public unsafe class IL2CPPDetourMethodPatcher : MethodPatcher
         var unmanagedDelegateType = DelegateTypeFactory.instance.CreateDelegateType(unmanagedTrampolineMethod,
             CallingConvention.Cdecl);
 
+        var unmanagedDelegate = unmanagedTrampolineMethod.CreateDelegate(unmanagedDelegateType);
+
+        DelegateCache[Original] = unmanagedDelegate;
+
         var detourPtr =
-            Marshal.GetFunctionPointerForDelegate(unmanagedTrampolineMethod.CreateDelegate(unmanagedDelegateType));
+            Marshal.GetFunctionPointerForDelegate(unmanagedDelegate);
         nativeDetour = INativeDetour.Create(originalNativeMethodInfo.MethodPointer, detourPtr);
         nativeDetour.Apply();
         modifiedNativeMethodInfo.MethodPointer = nativeDetour.TrampolinePtr;

BepInEx.IL2CPP/IL2CPPChainloader.cs

@@ -1,4 +1,5 @@
-using System;
+using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
 using System.Reflection;
@@ -34,6 +35,8 @@ public class IL2CPPChainloader : BaseChainloader<BasePlugin>
      false,
      "Include unity log messages in log file output.");
 
+    private static List<object> DetourCache = new();
+
     private static INativeDetour RuntimeInvokeDetour { get; set; }
 
     public static IL2CPPChainloader Instance { get; set; }
@@ -74,9 +77,12 @@ public class IL2CPPChainloader : BaseChainloader<BasePlugin>
 
         gameAssemblyModule.BaseAddress.TryGetFunction("il2cpp_runtime_invoke", out var runtimeInvokePtr);
         PreloaderLogger.Log.Log(LogLevel.Debug, $"Runtime invoke pointer: 0x{runtimeInvokePtr.ToInt64():X}");
-        RuntimeInvokeDetour =
-            INativeDetour.CreateAndApply(runtimeInvokePtr, OnInvokeMethod, out originalInvoke);
+        RuntimeInvokeDetourDelegate invokeMethodDetour = OnInvokeMethod;
 
+        RuntimeInvokeDetour =
+            INativeDetour.CreateAndApply(runtimeInvokePtr, invokeMethodDetour, out originalInvoke);
+        DetourCache.Add(invokeMethodDetour);
+        DetourCache.Add(originalInvoke);
         PreloaderLogger.Log.Log(LogLevel.Debug, "Runtime invoke patched");
     }
 
@@ -113,6 +119,8 @@ public class IL2CPPChainloader : BaseChainloader<BasePlugin>
         {
             RuntimeInvokeDetour.Dispose();
 
+            DetourCache.Clear();
+
             PreloaderLogger.Log.Log(LogLevel.Debug, "Runtime invoke unpatched");
         }