C#: Ensure we only create one CSharpScript per type

Previously, for each scripts class instance that was created from code
rather than by the engine, we were constructing, configuring and
assigning a new CSharpScript.
This has changed now and we make sure there's only one CSharpScript
associated to each type.

9 files changed, 141 insertions, 136 deletions

diff --git a/modules/mono/csharp_script.cpp b/modules/mono/csharp_script.cpp
index 99bd3edb9e..ae464700ff 100644
--- a/modules/mono/csharp_script.cpp
+++ b/modules/mono/csharp_script.cpp
@@ -104,7 +104,7 @@ Error CSharpLanguage::execute_file(const String &p_path) {
 	return OK;
 }
 
-extern void *godotsharp_pinvoke_funcs[179];
+extern void *godotsharp_pinvoke_funcs[181];
 [[maybe_unused]] volatile void **do_not_strip_godotsharp_pinvoke_funcs;
 #ifdef TOOLS_ENABLED
 extern void *godotsharp_editor_pinvoke_funcs[30];
@@ -793,6 +793,20 @@ void CSharpLanguage::reload_assemblies(bool p_soft_reload) {
 	// (while hot-reload is not yet implemented)
 	gdmono->initialize_load_assemblies();
 
+	{
+		MutexLock lock(script_instances_mutex);
+
+		for (SelfList<CSharpScript> *elem = script_list.first(); elem; elem = elem->next()) {
+			Ref<CSharpScript> script(elem->self());
+
+			script->exports_invalidated = true;
+
+			if (!script->get_path().is_empty()) {
+				script->reload(p_soft_reload);
+			}
+		}
+	}
+
 #if 0
 	// There is no soft reloading with Mono. It's always hard reloading.
 
@@ -1010,7 +1024,7 @@ void CSharpLanguage::reload_assemblies(bool p_soft_reload) {
 
 			GDMonoClass *native = GDMonoUtils::get_class_native_base(script_class);
 
-			CSharpScript::initialize_for_managed_type(script, script_class, native);
+			CSharpScript::reload_registered_script(script, script_class, native);
 		}
 
 		StringName native_name = NATIVE_GDMONOCLASS_NAME(script->native);
@@ -1563,9 +1577,13 @@ void CSharpLanguage::tie_native_managed_to_unmanaged(GCHandleIntPtr p_gchandle_i
 	CSharpLanguage::set_instance_binding(p_unmanaged, data);
 }
 
-void CSharpLanguage::tie_user_managed_to_unmanaged(GCHandleIntPtr p_gchandle_intptr, Object *p_unmanaged, CSharpScript *p_script, bool p_ref_counted) {
+void CSharpLanguage::tie_user_managed_to_unmanaged(GCHandleIntPtr p_gchandle_intptr, Object *p_unmanaged, Ref<CSharpScript> *p_script, bool p_ref_counted) {
 	// This method should not fail
 
+	Ref<CSharpScript> script = *p_script;
+	// We take care of destructing this reference here, so the managed code won't need to do another P/Invoke call
+	p_script->~Ref();
+
 	CRASH_COND(!p_unmanaged);
 
 	// All mono objects created from the managed world (e.g.: 'new Player()')
@@ -1578,12 +1596,8 @@ void CSharpLanguage::tie_user_managed_to_unmanaged(GCHandleIntPtr p_gchandle_int
 	MonoGCHandleData gchandle = MonoGCHandleData(p_gchandle_intptr,
 			p_ref_counted ? gdmono::GCHandleType::WEAK_HANDLE : gdmono::GCHandleType::STRONG_HANDLE);
 
-	Ref<CSharpScript> script = p_script;
-
 	CRASH_COND(script.is_null());
 
-	CSharpScript::initialize_for_managed_type(script);
-
 	CSharpInstance *csharp_instance = CSharpInstance::create_for_managed_type(p_unmanaged, script.ptr(), gchandle);
 
 	p_unmanaged->set_script_and_instance(script, csharp_instance);
@@ -2345,12 +2359,17 @@ void CSharpScript::_bind_methods() {
 	ClassDB::bind_vararg_method(METHOD_FLAGS_DEFAULT, "new", &CSharpScript::_new, MethodInfo("new"));
 }
 
-void CSharpScript::initialize_for_managed_type(Ref<CSharpScript> p_script) {
+void CSharpScript::reload_registered_script(Ref<CSharpScript> p_script) {
 	// IMPORTANT:
 	// This method must be called only after the CSharpScript and its associated type
 	// have been added to the script bridge map in the ScriptManagerBridge C# class.
+	// Other than that, it's the same as `CSharpScript::reload`.
 
-	// This method should not fail, only assertions allowed
+	// This method should not fail, only assertions allowed.
+
+	// Unlike `reload`, we print an error rather than silently returning,
+	// as we can assert this won't be called a second time until invalidated.
+	ERR_FAIL_COND(!p_script->reload_invalidated);
 
 	p_script->valid = true;
 	p_script->reload_invalidated = false;
@@ -2607,9 +2626,6 @@ Error CSharpScript::reload(bool p_keep_state) {
 
 	String script_path = get_path();
 
-	// In case it was already added by a previous reload
-	GDMonoCache::managed_callbacks.ScriptManagerBridge_RemoveScriptBridge(this);
-
 	valid = GDMonoCache::managed_callbacks.ScriptManagerBridge_AddScriptBridge(this, &script_path);
 
 	if (valid) {
@@ -2817,9 +2833,13 @@ Ref<Resource> ResourceFormatLoaderCSharpScript::load(const String &p_path, const
 
 	// TODO ignore anything inside bin/ and obj/ in tools builds?
 
-	CSharpScript *script = memnew(CSharpScript);
+	Ref<CSharpScript> script;
 
-	Ref<CSharpScript> scriptres(script);
+	if (GDMonoCache::godot_api_cache_updated) {
+		GDMonoCache::managed_callbacks.ScriptManagerBridge_GetOrCreateScriptBridgeForPath(&p_path, &script);
+	} else {
+		script = Ref<CSharpScript>(memnew(CSharpScript));
+	}
 
 #if defined(DEBUG_ENABLED) || defined(TOOLS_ENABLED)
 	Error err = script->load_source_code(p_path);
@@ -2834,7 +2854,7 @@ Ref<Resource> ResourceFormatLoaderCSharpScript::load(const String &p_path, const
 		*r_error = OK;
 	}
 
-	return scriptres;
+	return script;
 }
 
 void ResourceFormatLoaderCSharpScript::get_recognized_extensions(List<String> *p_extensions) const {
diff --git a/modules/mono/csharp_script.h b/modules/mono/csharp_script.h
index d4891395ba..eb72df9f42 100644
--- a/modules/mono/csharp_script.h
+++ b/modules/mono/csharp_script.h
@@ -134,7 +134,6 @@ private:
 
 	// Do not use unless you know what you are doing
 	static void update_script_class_info(Ref<CSharpScript> p_script);
-	static void initialize_for_managed_type(Ref<CSharpScript> p_script);
 
 protected:
 	static void _bind_methods();
@@ -144,6 +143,8 @@ protected:
 	void _get_property_list(List<PropertyInfo> *p_properties) const;
 
 public:
+	static void reload_registered_script(Ref<CSharpScript> p_script);
+
 	bool can_instantiate() const override;
 	StringName get_instance_base_type() const override;
 	ScriptInstance *instance_create(Object *p_this) override;
@@ -460,7 +461,7 @@ public:
 	bool setup_csharp_script_binding(CSharpScriptBinding &r_script_binding, Object *p_object);
 
 	static void tie_native_managed_to_unmanaged(GCHandleIntPtr p_gchandle_intptr, Object *p_unmanaged, const StringName *p_native_name, bool p_ref_counted);
-	static void tie_user_managed_to_unmanaged(GCHandleIntPtr p_gchandle_intptr, Object *p_unmanaged, CSharpScript *p_script, bool p_ref_counted);
+	static void tie_user_managed_to_unmanaged(GCHandleIntPtr p_gchandle_intptr, Object *p_unmanaged, Ref<CSharpScript> *p_script, bool p_ref_counted);
 	static void tie_managed_to_unmanaged_with_pre_setup(GCHandleIntPtr p_gchandle_intptr, Object *p_unmanaged);
 
 #warning TODO
diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/Bridge/ManagedCallbacks.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/Bridge/ManagedCallbacks.cs
index 7a6748b4eb..a348776874 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/Bridge/ManagedCallbacks.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/Bridge/ManagedCallbacks.cs
@@ -21,6 +21,7 @@ namespace Godot.Bridge
         public delegate* unmanaged<IntPtr, godot_string*, godot_bool> ScriptManagerBridge_HasScriptSignal;
         public delegate* unmanaged<IntPtr, IntPtr, godot_bool> ScriptManagerBridge_ScriptIsOrInherits;
         public delegate* unmanaged<IntPtr, godot_string*, godot_bool> ScriptManagerBridge_AddScriptBridge;
+        public delegate* unmanaged<godot_string*, godot_ref*, void> ScriptManagerBridge_GetOrCreateScriptBridgeForPath;
         public delegate* unmanaged<IntPtr, void> ScriptManagerBridge_RemoveScriptBridge;
         public delegate* unmanaged<IntPtr, godot_bool*, godot_dictionary*, void> ScriptManagerBridge_UpdateScriptClassInfo;
         public delegate* unmanaged<IntPtr, IntPtr*, godot_bool, godot_bool> ScriptManagerBridge_SwapGCHandleForType;
@@ -56,6 +57,7 @@ namespace Godot.Bridge
                 ScriptManagerBridge_HasScriptSignal = &ScriptManagerBridge.HasScriptSignal,
                 ScriptManagerBridge_ScriptIsOrInherits = &ScriptManagerBridge.ScriptIsOrInherits,
                 ScriptManagerBridge_AddScriptBridge = &ScriptManagerBridge.AddScriptBridge,
+                ScriptManagerBridge_GetOrCreateScriptBridgeForPath = &ScriptManagerBridge.GetOrCreateScriptBridgeForPath,
                 ScriptManagerBridge_RemoveScriptBridge = &ScriptManagerBridge.RemoveScriptBridge,
                 ScriptManagerBridge_UpdateScriptClassInfo = &ScriptManagerBridge.UpdateScriptClassInfo,
                 ScriptManagerBridge_SwapGCHandleForType = &ScriptManagerBridge.SwapGCHandleForType,
diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/Bridge/ScriptManagerBridge.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/Bridge/ScriptManagerBridge.cs
index 8348598b65..d812626fab 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/Bridge/ScriptManagerBridge.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/Bridge/ScriptManagerBridge.cs
@@ -12,22 +12,11 @@ namespace Godot.Bridge
 {
     public static class ScriptManagerBridge
     {
-        private static System.Collections.Generic.Dictionary<string, ScriptLookupInfo> _scriptLookupMap = new();
-        private static System.Collections.Generic.Dictionary<IntPtr, Type> _scriptBridgeMap = new();
+        private static System.Collections.Generic.Dictionary<string, Type> _pathScriptMap = new();
 
-        private struct ScriptLookupInfo
-        {
-            public string ClassNamespace { get; private set; }
-            public string ClassName { get; private set; }
-            public Type ScriptType { get; private set; }
-
-            public ScriptLookupInfo(string classNamespace, string className, Type scriptType)
-            {
-                ClassNamespace = classNamespace;
-                ClassName = className;
-                ScriptType = scriptType;
-            }
-        };
+        private static readonly object ScriptBridgeLock = new();
+        private static System.Collections.Generic.Dictionary<IntPtr, Type> _scriptTypeMap = new();
+        private static System.Collections.Generic.Dictionary<Type, IntPtr> _typeScriptMap = new();
 
         [UnmanagedCallersOnly]
         internal static void FrameCallback()
@@ -80,7 +69,7 @@ namespace Godot.Bridge
             try
             {
                 // Performance is not critical here as this will be replaced with source generators.
-                Type scriptType = _scriptBridgeMap[scriptPtr];
+                Type scriptType = _scriptTypeMap[scriptPtr];
                 var obj = (Object)FormatterServices.GetUninitializedObject(scriptType);
 
                 var ctor = scriptType
@@ -133,7 +122,7 @@ namespace Godot.Bridge
             try
             {
                 // Performance is not critical here as this will be replaced with source generators.
-                if (!_scriptBridgeMap.TryGetValue(scriptPtr, out var scriptType))
+                if (!_scriptTypeMap.TryGetValue(scriptPtr, out var scriptType))
                 {
                     *outRes = default;
                     return;
@@ -225,7 +214,7 @@ namespace Godot.Bridge
                 if (scriptPathAttr == null)
                     return;
 
-                _scriptLookupMap[scriptPathAttr.Path] = new ScriptLookupInfo(type.Namespace, type.Name, type);
+                _pathScriptMap[scriptPathAttr.Path] = type;
             }
 
             var assemblyHasScriptsAttr = assembly.GetCustomAttributes(inherit: false)
@@ -304,7 +293,7 @@ namespace Godot.Bridge
                 // Performance is not critical here as this will be replaced with source generators.
                 using var signals = new Dictionary();
 
-                Type top = _scriptBridgeMap[scriptPtr];
+                Type top = _scriptTypeMap[scriptPtr];
                 Type native = Object.InternalGetClassNativeBase(top);
 
                 while (top != null && top != native)
@@ -400,7 +389,7 @@ namespace Godot.Bridge
 
                 string signalNameStr = Marshaling.ConvertStringToManaged(*signalName);
 
-                Type top = _scriptBridgeMap[scriptPtr];
+                Type top = _scriptTypeMap[scriptPtr];
                 Type native = Object.InternalGetClassNativeBase(top);
 
                 while (top != null && top != native)
@@ -446,10 +435,10 @@ namespace Godot.Bridge
         {
             try
             {
-                if (!_scriptBridgeMap.TryGetValue(scriptPtr, out var scriptType))
+                if (!_scriptTypeMap.TryGetValue(scriptPtr, out var scriptType))
                     return false.ToGodotBool();
 
-                if (!_scriptBridgeMap.TryGetValue(scriptPtrMaybeBase, out var maybeBaseType))
+                if (!_scriptTypeMap.TryGetValue(scriptPtrMaybeBase, out var maybeBaseType))
                     return false.ToGodotBool();
 
                 return (scriptType == maybeBaseType || maybeBaseType.IsAssignableFrom(scriptType)).ToGodotBool();
@@ -466,12 +455,19 @@ namespace Godot.Bridge
         {
             try
             {
-                string scriptPathStr = Marshaling.ConvertStringToManaged(*scriptPath);
+                lock (ScriptBridgeLock)
+                {
+                    if (!_scriptTypeMap.ContainsKey(scriptPtr))
+                    {
+                        string scriptPathStr = Marshaling.ConvertStringToManaged(*scriptPath);
 
-                if (!_scriptLookupMap.TryGetValue(scriptPathStr, out var lookupInfo))
-                    return false.ToGodotBool();
+                        if (!_pathScriptMap.TryGetValue(scriptPathStr, out Type scriptType))
+                            return false.ToGodotBool();
 
-                _scriptBridgeMap.Add(scriptPtr, lookupInfo.ScriptType);
+                        _scriptTypeMap.Add(scriptPtr, scriptType);
+                        _typeScriptMap.Add(scriptType, scriptPtr);
+                    }
+                }
 
                 return true.ToGodotBool();
             }
@@ -482,15 +478,49 @@ namespace Godot.Bridge
             }
         }
 
-        internal static void AddScriptBridgeWithType(IntPtr scriptPtr, Type scriptType)
-            => _scriptBridgeMap.Add(scriptPtr, scriptType);
+        [UnmanagedCallersOnly]
+        internal static unsafe void GetOrCreateScriptBridgeForPath(godot_string* scriptPath, godot_ref* outScript)
+        {
+            string scriptPathStr = Marshaling.ConvertStringToManaged(*scriptPath);
+
+            if (!_pathScriptMap.TryGetValue(scriptPathStr, out Type scriptType))
+            {
+                NativeFuncs.godotsharp_internal_new_csharp_script(outScript);
+                return;
+            }
+
+            GetOrCreateScriptBridgeForType(scriptType, outScript);
+        }
+
+        internal static unsafe void GetOrCreateScriptBridgeForType(Type scriptType, godot_ref* outScript)
+        {
+            lock (ScriptBridgeLock)
+            {
+                if (_typeScriptMap.TryGetValue(scriptType, out IntPtr scriptPtr))
+                {
+                    NativeFuncs.godotsharp_ref_new_from_ref_counted_ptr(out *outScript, scriptPtr);
+                    return;
+                }
+
+                NativeFuncs.godotsharp_internal_new_csharp_script(outScript);
+                scriptPtr = outScript->Reference;
+
+                _scriptTypeMap.Add(scriptPtr, scriptType);
+                _typeScriptMap.Add(scriptType, scriptPtr);
+
+                NativeFuncs.godotsharp_internal_reload_registered_script(scriptPtr);
+            }
+        }
 
         [UnmanagedCallersOnly]
         internal static void RemoveScriptBridge(IntPtr scriptPtr)
         {
             try
             {
-                _scriptBridgeMap.Remove(scriptPtr);
+                lock (ScriptBridgeLock)
+                {
+                    _ = _scriptTypeMap.Remove(scriptPtr);
+                }
             }
             catch (Exception e)
             {
@@ -505,7 +535,7 @@ namespace Godot.Bridge
             try
             {
                 // Performance is not critical here as this will be replaced with source generators.
-                var scriptType = _scriptBridgeMap[scriptPtr];
+                var scriptType = _scriptTypeMap[scriptPtr];
 
                 *outTool = scriptType.GetCustomAttributes(inherit: false)
                     .OfType<ToolAttribute>()
@@ -630,7 +660,7 @@ namespace Godot.Bridge
         {
             try
             {
-                Type scriptType = _scriptBridgeMap[scriptPtr];
+                Type scriptType = _scriptTypeMap[scriptPtr];
                 GetPropertyInfoListForType(scriptType, scriptPtr, addPropInfoFunc);
             }
             catch (Exception e)
@@ -752,7 +782,7 @@ namespace Godot.Bridge
         {
             try
             {
-                Type top = _scriptBridgeMap[scriptPtr];
+                Type top = _scriptTypeMap[scriptPtr];
                 Type native = Object.InternalGetClassNativeBase(top);
 
                 while (top != null && top != native)
diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/NativeInterop/InteropUtils.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/NativeInterop/InteropUtils.cs
index 8ddf28ba16..f6f0186016 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/NativeInterop/InteropUtils.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/NativeInterop/InteropUtils.cs
@@ -60,13 +60,17 @@ namespace Godot.NativeInterop
             }
             else
             {
-                IntPtr scriptPtr = NativeFuncs.godotsharp_internal_new_csharp_script();
-
-                ScriptManagerBridge.AddScriptBridgeWithType(scriptPtr, type);
-
-                // IMPORTANT: This must be called after AddScriptWithTypeBridge
-                NativeFuncs.godotsharp_internal_tie_user_managed_to_unmanaged(
-                    GCHandle.ToIntPtr(gcHandle), unmanaged, scriptPtr, refCounted.ToGodotBool());
+                unsafe
+                {
+                    // We don't dispose `script` ourselves here.
+                    // `tie_user_managed_to_unmanaged` does it for us to avoid another P/Invoke call.
+                    godot_ref script;
+                    ScriptManagerBridge.GetOrCreateScriptBridgeForType(type, &script);
+
+                    // IMPORTANT: This must be called after GetOrCreateScriptBridgeForType
+                    NativeFuncs.godotsharp_internal_tie_user_managed_to_unmanaged(
+                        GCHandle.ToIntPtr(gcHandle), unmanaged, &script, refCounted.ToGodotBool());
+                }
             }
         }
 
diff --git a/modules/mono/glue/GodotSharp/GodotSharp/Core/NativeInterop/NativeFuncs.cs b/modules/mono/glue/GodotSharp/GodotSharp/Core/NativeInterop/NativeFuncs.cs
index 01add1bf45..2c81ae7816 100644
--- a/modules/mono/glue/GodotSharp/GodotSharp/Core/NativeInterop/NativeFuncs.cs
+++ b/modules/mono/glue/GodotSharp/GodotSharp/Core/NativeInterop/NativeFuncs.cs
@@ -42,7 +42,8 @@ namespace Godot.NativeInterop
         internal static extern void godotsharp_internal_object_disposed(IntPtr ptr, IntPtr gcHandleToFree);
 
         [DllImport(GodotDllName)]
-        internal static extern void godotsharp_internal_refcounted_disposed(IntPtr ptr, IntPtr gcHandleToFree, godot_bool isFinalizer);
+        internal static extern void godotsharp_internal_refcounted_disposed(IntPtr ptr, IntPtr gcHandleToFree,
+            godot_bool isFinalizer);
 
         [DllImport(GodotDllName)]
         internal static extern void godotsharp_internal_object_connect_event_signal(IntPtr obj,
@@ -59,7 +60,7 @@ namespace Godot.NativeInterop
 
         [DllImport(GodotDllName)]
         internal static extern void godotsharp_internal_tie_user_managed_to_unmanaged(IntPtr gcHandleIntPtr,
-            IntPtr unmanaged, IntPtr scriptPtr, godot_bool refCounted);
+            IntPtr unmanaged, godot_ref* scriptPtr, godot_bool refCounted);
 
         [DllImport(GodotDllName)]
         internal static extern void godotsharp_internal_tie_managed_to_unmanaged_with_pre_setup(
@@ -77,7 +78,10 @@ namespace Godot.NativeInterop
             IntPtr oldGCHandlePtr);
 
         [DllImport(GodotDllName)]
-        internal static extern IntPtr godotsharp_internal_new_csharp_script();
+        internal static extern void godotsharp_internal_new_csharp_script(godot_ref* r_script);
+
+        [DllImport(GodotDllName)]
+        internal static extern void godotsharp_internal_reload_registered_script(IntPtr scriptPtr);
 
         [DllImport(GodotDllName)]
         internal static extern void godotsharp_array_filter_godot_objects_by_native(in godot_string_name p_native_name,
@@ -88,6 +92,9 @@ namespace Godot.NativeInterop
             out godot_array r_output);
 
         [DllImport(GodotDllName)]
+        public static extern void godotsharp_ref_new_from_ref_counted_ptr(out godot_ref r_dest, IntPtr p_ref_counted_ptr);
+
+        [DllImport(GodotDllName)]
         public static extern void godotsharp_ref_destroy(ref godot_ref p_instance);
 
         [DllImport(GodotDllName)]
diff --git a/modules/mono/glue/runtime_interop.cpp b/modules/mono/glue/runtime_interop.cpp
index 7150e2e35b..84db9473c5 100644
--- a/modules/mono/glue/runtime_interop.cpp
+++ b/modules/mono/glue/runtime_interop.cpp
@@ -285,7 +285,7 @@ GD_PINVOKE_EXPORT void godotsharp_internal_tie_native_managed_to_unmanaged(GCHan
 	CSharpLanguage::tie_native_managed_to_unmanaged(p_gchandle_intptr, p_unmanaged, p_native_name, p_ref_counted);
 }
 
-GD_PINVOKE_EXPORT void godotsharp_internal_tie_user_managed_to_unmanaged(GCHandleIntPtr p_gchandle_intptr, Object *p_unmanaged, CSharpScript *p_script, bool p_ref_counted) {
+GD_PINVOKE_EXPORT void godotsharp_internal_tie_user_managed_to_unmanaged(GCHandleIntPtr p_gchandle_intptr, Object *p_unmanaged, Ref<CSharpScript> *p_script, bool p_ref_counted) {
 	CSharpLanguage::tie_user_managed_to_unmanaged(p_gchandle_intptr, p_unmanaged, p_script, p_ref_counted);
 }
 
@@ -293,10 +293,13 @@ GD_PINVOKE_EXPORT void godotsharp_internal_tie_managed_to_unmanaged_with_pre_set
 	CSharpLanguage::tie_managed_to_unmanaged_with_pre_setup(p_gchandle_intptr, p_unmanaged);
 }
 
-GD_PINVOKE_EXPORT CSharpScript *godotsharp_internal_new_csharp_script() {
-	CSharpScript *script = memnew(CSharpScript);
-	CRASH_COND(!script);
-	return script;
+GD_PINVOKE_EXPORT void godotsharp_internal_new_csharp_script(Ref<CSharpScript> *r_dest) {
+	memnew_placement(r_dest, Ref<CSharpScript>(memnew(CSharpScript)));
+}
+
+GD_PINVOKE_EXPORT void godotsharp_internal_reload_registered_script(CSharpScript *p_script) {
+	CRASH_COND(!p_script);
+	CSharpScript::reload_registered_script(Ref<CSharpScript>(p_script));
 }
 
 GD_PINVOKE_EXPORT void godotsharp_array_filter_godot_objects_by_native(StringName *p_native_name, const Array *p_input, Array *r_output) {
@@ -321,6 +324,10 @@ GD_PINVOKE_EXPORT void godotsharp_array_filter_godot_objects_by_non_native(const
 	}
 }
 
+GD_PINVOKE_EXPORT void godotsharp_ref_new_from_ref_counted_ptr(Ref<RefCounted> *r_dest, RefCounted *p_ref_counted_ptr) {
+	memnew_placement(r_dest, Ref<RefCounted>(p_ref_counted_ptr));
+}
+
 GD_PINVOKE_EXPORT void godotsharp_ref_destroy(Ref<RefCounted> *p_instance) {
 	p_instance->~Ref();
 }
@@ -1281,7 +1288,7 @@ GD_PINVOKE_EXPORT void godotsharp_object_to_string(Object *p_ptr, godot_string *
 #endif
 
 // We need this to prevent the functions from being stripped.
-void *godotsharp_pinvoke_funcs[179] = {
+void *godotsharp_pinvoke_funcs[181] = {
 	(void *)godotsharp_method_bind_get_method,
 	(void *)godotsharp_get_class_constructor,
 	(void *)godotsharp_engine_get_singleton,
@@ -1297,8 +1304,10 @@ void *godotsharp_pinvoke_funcs[179] = {
 	(void *)godotsharp_internal_tie_user_managed_to_unmanaged,
 	(void *)godotsharp_internal_tie_managed_to_unmanaged_with_pre_setup,
 	(void *)godotsharp_internal_new_csharp_script,
+	(void *)godotsharp_internal_reload_registered_script,
 	(void *)godotsharp_array_filter_godot_objects_by_native,
 	(void *)godotsharp_array_filter_godot_objects_by_non_native,
+	(void *)godotsharp_ref_new_from_ref_counted_ptr,
 	(void *)godotsharp_ref_destroy,
 	(void *)godotsharp_string_name_new_from_string,
 	(void *)godotsharp_node_path_new_from_string,
diff --git a/modules/mono/mono_gd/gd_mono.cpp b/modules/mono/mono_gd/gd_mono.cpp
index 0792a88f52..7adb6f60eb 100644
--- a/modules/mono/mono_gd/gd_mono.cpp
+++ b/modules/mono/mono_gd/gd_mono.cpp
@@ -49,10 +49,9 @@
 #include <coreclr_delegates.h>
 #include <hostfxr.h>
 
-#warning TODO mobile
+// TODO mobile
 #if 0
 #ifdef ANDROID_ENABLED
-#include "android_mono_config.h"
 #include "support/android_support.h"
 #elif defined(IOS_ENABLED)
 #include "support/ios_support.h"
@@ -62,75 +61,6 @@
 GDMono *GDMono::singleton = nullptr;
 
 namespace {
-
-#warning "TODO .NET debugging and profiling. What's needed?"
-#if 0
-void gd_mono_profiler_init() {
-	String profiler_args = GLOBAL_DEF("mono/profiler/args", "log:calls,alloc,sample,output=output.mlpd");
-	bool profiler_enabled = GLOBAL_DEF("mono/profiler/enabled", false);
-	if (profiler_enabled) {
-		mono_profiler_load(profiler_args.utf8());
-		return;
-	}
-
-	const String env_var_name = "MONO_ENV_OPTIONS";
-	if (OS::get_singleton()->has_environment(env_var_name)) {
-		const String mono_env_ops = OS::get_singleton()->get_environment(env_var_name);
-		// Usually MONO_ENV_OPTIONS looks like:   --profile=jb:prof=timeline,ctl=remote,host=127.0.0.1:55467
-		const String prefix = "--profile=";
-		if (mono_env_ops.begins_with(prefix)) {
-			const String ops = mono_env_ops.substr(prefix.length(), mono_env_ops.length());
-			mono_profiler_load(ops.utf8());
-		}
-	}
-}
-
-void gd_mono_debug_init() {
-	CharString da_args = OS::get_singleton()->get_environment("GODOT_MONO_DEBUGGER_AGENT").utf8();
-
-	if (da_args.length()) {
-		OS::get_singleton()->set_environment("GODOT_MONO_DEBUGGER_AGENT", String());
-	}
-
-#ifdef TOOLS_ENABLED
-	int da_port = GLOBAL_DEF("mono/debugger_agent/port", 23685);
-	bool da_suspend = GLOBAL_DEF("mono/debugger_agent/wait_for_debugger", false);
-	int da_timeout = GLOBAL_DEF("mono/debugger_agent/wait_timeout", 3000);
-
-	if (Engine::get_singleton()->is_editor_hint() ||
-			ProjectSettings::get_singleton()->get_resource_path().is_empty() ||
-			Engine::get_singleton()->is_project_manager_hint()) {
-		if (da_args.size() == 0) {
-			return;
-		}
-	}
-
-	if (da_args.length() == 0) {
-		da_args = String("--debugger-agent=transport=dt_socket,address=127.0.0.1:" + itos(da_port) +
-				",embedding=1,server=y,suspend=" + (da_suspend ? "y,timeout=" + itos(da_timeout) : "n"))
-						  .utf8();
-	}
-#else
-	if (da_args.length() == 0) {
-		return; // Exported games don't use the project settings to setup the debugger agent
-	}
-#endif
-
-	// Debugging enabled
-
-	mono_debug_init(MONO_DEBUG_FORMAT_MONO);
-
-	// --debugger-agent=help
-	const char *options[] = {
-		"--soft-breakpoints",
-		da_args.get_data()
-	};
-	mono_jit_parse_options(2, (char **)options);
-}
-#endif
-} // namespace
-
-namespace {
 hostfxr_initialize_for_dotnet_command_line_fn hostfxr_initialize_for_dotnet_command_line = nullptr;
 hostfxr_initialize_for_runtime_config_fn hostfxr_initialize_for_runtime_config = nullptr;
 hostfxr_get_runtime_delegate_fn hostfxr_get_runtime_delegate = nullptr;
diff --git a/modules/mono/mono_gd/gd_mono_cache.h b/modules/mono/mono_gd/gd_mono_cache.h
index 7a75532fb7..7daa4c92d3 100644
--- a/modules/mono/mono_gd/gd_mono_cache.h
+++ b/modules/mono/mono_gd/gd_mono_cache.h
@@ -84,6 +84,7 @@ struct ManagedCallbacks {
 	using FuncScriptManagerBridge_HasScriptSignal = bool(GD_CLR_STDCALL *)(const CSharpScript *, const String *);
 	using FuncScriptManagerBridge_ScriptIsOrInherits = bool(GD_CLR_STDCALL *)(const CSharpScript *, const CSharpScript *);
 	using FuncScriptManagerBridge_AddScriptBridge = bool(GD_CLR_STDCALL *)(const CSharpScript *, const String *);
+	using FuncScriptManagerBridge_GetOrCreateScriptBridgeForPath = void(GD_CLR_STDCALL *)(const String *, Ref<CSharpScript> *);
 	using FuncScriptManagerBridge_RemoveScriptBridge = void(GD_CLR_STDCALL *)(const CSharpScript *);
 	using FuncScriptManagerBridge_UpdateScriptClassInfo = void(GD_CLR_STDCALL *)(const CSharpScript *, bool *, Dictionary *);
 	using FuncScriptManagerBridge_SwapGCHandleForType = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, GCHandleIntPtr *, bool);
@@ -113,6 +114,7 @@ struct ManagedCallbacks {
 	FuncScriptManagerBridge_HasScriptSignal ScriptManagerBridge_HasScriptSignal;
 	FuncScriptManagerBridge_ScriptIsOrInherits ScriptManagerBridge_ScriptIsOrInherits;
 	FuncScriptManagerBridge_AddScriptBridge ScriptManagerBridge_AddScriptBridge;
+	FuncScriptManagerBridge_GetOrCreateScriptBridgeForPath ScriptManagerBridge_GetOrCreateScriptBridgeForPath;
 	FuncScriptManagerBridge_RemoveScriptBridge ScriptManagerBridge_RemoveScriptBridge;
 	FuncScriptManagerBridge_UpdateScriptClassInfo ScriptManagerBridge_UpdateScriptClassInfo;
 	FuncScriptManagerBridge_SwapGCHandleForType ScriptManagerBridge_SwapGCHandleForType;