C#: Re-implement assembly reloading with ALCs

4 files changed, 57 insertions, 87 deletions

diff --git a/modules/mono/mono_gd/gd_mono.cpp b/modules/mono/mono_gd/gd_mono.cpp
index d57ad2831a..f5e38c2e61 100644
--- a/modules/mono/mono_gd/gd_mono.cpp
+++ b/modules/mono/mono_gd/gd_mono.cpp
@@ -501,106 +501,48 @@ void GDMono::_init_godot_api_hashes() {
 
 #ifdef TOOLS_ENABLED
 bool GDMono::_load_project_assembly() {
-	String appname = ProjectSettings::get_singleton()->get("application/config/name");
-	String appname_safe = OS::get_singleton()->get_safe_dir_name(appname);
-	if (appname_safe.is_empty()) {
-		appname_safe = "UnnamedProject";
-	}
+	String appname_safe = ProjectSettings::get_singleton()->get_safe_project_name();
 
 	String assembly_path = GodotSharpDirs::get_res_temp_assemblies_dir()
 								   .plus_file(appname_safe + ".dll");
 	assembly_path = ProjectSettings::get_singleton()->globalize_path(assembly_path);
 
-	return plugin_callbacks.LoadProjectAssemblyCallback(assembly_path.utf16());
-}
-#endif
-
-#warning TODO hot-reload
-#if 0
-Error GDMono::_unload_scripts_domain() {
-	ERR_FAIL_NULL_V(scripts_domain, ERR_BUG);
-
-	CSharpLanguage::get_singleton()->_on_scripts_domain_about_to_unload();
-
-	print_verbose("Mono: Finalizing scripts domain...");
-
-	if (mono_domain_get() != root_domain) {
-		mono_domain_set(root_domain, true);
-	}
-
-	finalizing_scripts_domain = true;
+	String loaded_assembly_path;
+	bool success = plugin_callbacks.LoadProjectAssemblyCallback(assembly_path.utf16(), &loaded_assembly_path);
 
-	if (!mono_domain_finalize(scripts_domain, 2000)) {
-		ERR_PRINT("Mono: Domain finalization timeout.");
+	if (success) {
+		project_assembly_path = loaded_assembly_path.simplify_path();
+		project_assembly_modified_time = FileAccess::get_modified_time(loaded_assembly_path);
 	}
 
-	finalizing_scripts_domain = false;
-
-	mono_gc_collect(mono_gc_max_generation());
-
-	core_api_assembly = nullptr;
-#ifdef TOOLS_ENABLED
-	editor_api_assembly = nullptr;
-#endif
-
-	project_assembly = nullptr;
-#ifdef TOOLS_ENABLED
-	tools_assembly = nullptr;
-#endif
-
-	MonoDomain *domain = scripts_domain;
-	scripts_domain = nullptr;
-
-	print_verbose("Mono: Unloading scripts domain...");
-
-	MonoException *exc = nullptr;
-	mono_domain_try_unload(domain, (MonoObject **)&exc);
-
-	if (exc) {
-		ERR_PRINT("Exception thrown when unloading scripts domain.");
-		GDMonoUtils::debug_unhandled_exception(exc);
-		return FAILED;
-	}
-
-	return OK;
+	return success;
 }
+#endif
 
 #ifdef GD_MONO_HOT_RELOAD
-Error GDMono::reload_scripts_domain() {
+Error GDMono::reload_project_assemblies() {
 	ERR_FAIL_COND_V(!runtime_initialized, ERR_BUG);
 
-	if (scripts_domain) {
-		Error domain_unload_err = _unload_scripts_domain();
-		ERR_FAIL_COND_V_MSG(domain_unload_err != OK, domain_unload_err, "Mono: Failed to unload scripts domain.");
-	}
-
-	Error domain_load_err = _load_scripts_domain();
-	ERR_FAIL_COND_V_MSG(domain_load_err != OK, domain_load_err, "Mono: Failed to load scripts domain.");
+	finalizing_scripts_domain = true;
 
-	// Load assemblies. The API and tools assemblies are required,
-	// the application is aborted if these assemblies cannot be loaded.
+	CSharpLanguage::get_singleton()->_on_scripts_domain_about_to_unload();
 
-	if (!_try_load_api_assemblies()) {
-		CRASH_NOW_MSG("Failed to load one of the API assemblies.");
+	if (!get_plugin_callbacks().UnloadProjectPluginCallback()) {
+		ERR_FAIL_V_MSG(Error::FAILED, ".NET: Failed to unload assemblies.");
 	}
 
-#if defined(TOOLS_ENABLED)
-	bool tools_assemblies_loaded = _load_tools_assemblies();
-	CRASH_COND_MSG(!tools_assemblies_loaded, "Mono: Failed to load '" TOOLS_ASM_NAME "' assemblies.");
-#endif
+	finalizing_scripts_domain = false;
 
 	// Load the project's main assembly. Here, during hot-reloading, we do
 	// consider failing to load the project's main assembly to be an error.
-	// However, unlike the API and tools assemblies, the application can continue working.
 	if (!_load_project_assembly()) {
-		print_error("Mono: Failed to load project assembly");
+		print_error(".NET: Failed to load project assembly.");
 		return ERR_CANT_OPEN;
 	}
 
 	return OK;
 }
 #endif
-#endif
 
 GDMono::GDMono() {
 	singleton = this;
diff --git a/modules/mono/mono_gd/gd_mono.h b/modules/mono/mono_gd/gd_mono.h
index 301782575c..776399a544 100644
--- a/modules/mono/mono_gd/gd_mono.h
+++ b/modules/mono/mono_gd/gd_mono.h
@@ -45,10 +45,12 @@ namespace gdmono {
 
 #ifdef TOOLS_ENABLED
 struct PluginCallbacks {
-	using FuncLoadProjectAssemblyCallback = bool(GD_CLR_STDCALL *)(const char16_t *);
+	using FuncLoadProjectAssemblyCallback = bool(GD_CLR_STDCALL *)(const char16_t *, String *);
 	using FuncLoadToolsAssemblyCallback = Object *(GD_CLR_STDCALL *)(const char16_t *);
+	using FuncUnloadProjectPluginCallback = bool(GD_CLR_STDCALL *)();
 	FuncLoadProjectAssemblyCallback LoadProjectAssemblyCallback = nullptr;
 	FuncLoadToolsAssemblyCallback LoadToolsAssemblyCallback = nullptr;
+	FuncUnloadProjectPluginCallback UnloadProjectPluginCallback = nullptr;
 };
 #endif
 
@@ -63,14 +65,13 @@ class GDMono {
 	void *hostfxr_dll_handle = nullptr;
 	bool is_native_aot = false;
 
+	String project_assembly_path;
+	uint64_t project_assembly_modified_time = 0;
+
 #ifdef TOOLS_ENABLED
 	bool _load_project_assembly();
 #endif
 
-	bool _try_load_api_assemblies();
-
-	Error _unload_scripts_domain();
-
 	uint64_t api_core_hash;
 #ifdef TOOLS_ENABLED
 	uint64_t api_editor_hash;
@@ -114,17 +115,32 @@ public:
 #endif
 	}
 
-	static GDMono *get_singleton() { return singleton; }
+	static GDMono *get_singleton() {
+		return singleton;
+	}
+
+	_FORCE_INLINE_ bool is_runtime_initialized() const {
+		return runtime_initialized;
+	}
+	_FORCE_INLINE_ bool is_finalizing_scripts_domain() {
+		return finalizing_scripts_domain;
+	}
 
-	_FORCE_INLINE_ bool is_runtime_initialized() const { return runtime_initialized; }
-	_FORCE_INLINE_ bool is_finalizing_scripts_domain() { return finalizing_scripts_domain; }
+	_FORCE_INLINE_ const String &get_project_assembly_path() const {
+		return project_assembly_path;
+	}
+	_FORCE_INLINE_ uint64_t get_project_assembly_modified_time() const {
+		return project_assembly_modified_time;
+	}
 
 #ifdef TOOLS_ENABLED
-	const gdmono::PluginCallbacks &get_plugin_callbacks() { return plugin_callbacks; }
+	const gdmono::PluginCallbacks &get_plugin_callbacks() {
+		return plugin_callbacks;
+	}
 #endif
 
 #ifdef GD_MONO_HOT_RELOAD
-	Error reload_scripts_domain();
+	Error reload_project_assemblies();
 #endif
 
 	void initialize();
diff --git a/modules/mono/mono_gd/gd_mono_cache.cpp b/modules/mono/mono_gd/gd_mono_cache.cpp
index fc47a0e09b..37433c59ee 100644
--- a/modules/mono/mono_gd/gd_mono_cache.cpp
+++ b/modules/mono/mono_gd/gd_mono_cache.cpp
@@ -52,6 +52,8 @@ void update_godot_api_cache(const ManagedCallbacks &p_managed_callbacks) {
 	CHECK_CALLBACK_NOT_NULL(SignalAwaiter, SignalCallback);
 	CHECK_CALLBACK_NOT_NULL(DelegateUtils, InvokeWithVariantArgs);
 	CHECK_CALLBACK_NOT_NULL(DelegateUtils, DelegateEquals);
+	CHECK_CALLBACK_NOT_NULL(DelegateUtils, TrySerializeDelegateWithGCHandle);
+	CHECK_CALLBACK_NOT_NULL(DelegateUtils, TryDeserializeDelegateWithGCHandle);
 	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, FrameCallback);
 	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, CreateManagedForGodotObjectBinding);
 	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, CreateManagedForGodotObjectScriptInstance);
@@ -64,6 +66,7 @@ void update_godot_api_cache(const ManagedCallbacks &p_managed_callbacks) {
 	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, AddScriptBridge);
 	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, GetOrCreateScriptBridgeForPath);
 	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, RemoveScriptBridge);
+	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, TryReloadRegisteredScriptWithClass);
 	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, UpdateScriptClassInfo);
 	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, SwapGCHandleForType);
 	CHECK_CALLBACK_NOT_NULL(ScriptManagerBridge, GetPropertyInfoList);
@@ -74,6 +77,8 @@ void update_godot_api_cache(const ManagedCallbacks &p_managed_callbacks) {
 	CHECK_CALLBACK_NOT_NULL(CSharpInstanceBridge, CallDispose);
 	CHECK_CALLBACK_NOT_NULL(CSharpInstanceBridge, CallToString);
 	CHECK_CALLBACK_NOT_NULL(CSharpInstanceBridge, HasMethodUnknownParams);
+	CHECK_CALLBACK_NOT_NULL(CSharpInstanceBridge, SerializeState);
+	CHECK_CALLBACK_NOT_NULL(CSharpInstanceBridge, DeserializeState);
 	CHECK_CALLBACK_NOT_NULL(GCHandleBridge, FreeGCHandle);
 	CHECK_CALLBACK_NOT_NULL(DebuggingUtils, GetCurrentStackInfo);
 	CHECK_CALLBACK_NOT_NULL(DisposablesTracker, OnGodotShuttingDown);
diff --git a/modules/mono/mono_gd/gd_mono_cache.h b/modules/mono/mono_gd/gd_mono_cache.h
index 763a7f3e5e..92778cc2c9 100644
--- a/modules/mono/mono_gd/gd_mono_cache.h
+++ b/modules/mono/mono_gd/gd_mono_cache.h
@@ -74,6 +74,8 @@ struct ManagedCallbacks {
 	using FuncSignalAwaiter_SignalCallback = void(GD_CLR_STDCALL *)(GCHandleIntPtr, const Variant **, int32_t, bool *);
 	using FuncDelegateUtils_InvokeWithVariantArgs = void(GD_CLR_STDCALL *)(GCHandleIntPtr, const Variant **, uint32_t, const Variant *);
 	using FuncDelegateUtils_DelegateEquals = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, GCHandleIntPtr);
+	using FuncDelegateUtils_TrySerializeDelegateWithGCHandle = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, const Array *);
+	using FuncDelegateUtils_TryDeserializeDelegateWithGCHandle = bool(GD_CLR_STDCALL *)(const Array *, GCHandleIntPtr *);
 	using FuncScriptManagerBridge_FrameCallback = void(GD_CLR_STDCALL *)();
 	using FuncScriptManagerBridge_CreateManagedForGodotObjectBinding = GCHandleIntPtr(GD_CLR_STDCALL *)(const StringName *, Object *);
 	using FuncScriptManagerBridge_CreateManagedForGodotObjectScriptInstance = bool(GD_CLR_STDCALL *)(const CSharpScript *, Object *, const Variant **, int32_t);
@@ -86,7 +88,8 @@ struct ManagedCallbacks {
 	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_TryReloadRegisteredScriptWithClass = bool(GD_CLR_STDCALL *)(const CSharpScript *);
+	using FuncScriptManagerBridge_UpdateScriptClassInfo = void(GD_CLR_STDCALL *)(const CSharpScript *, bool *, Dictionary *, Ref<CSharpScript> *);
 	using FuncScriptManagerBridge_SwapGCHandleForType = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, GCHandleIntPtr *, bool);
 	using FuncScriptManagerBridge_GetPropertyInfoList = void(GD_CLR_STDCALL *)(CSharpScript *, Callback_ScriptManagerBridge_GetPropertyInfoList_Add);
 	using FuncScriptManagerBridge_GetPropertyDefaultValues = void(GD_CLR_STDCALL *)(CSharpScript *, Callback_ScriptManagerBridge_GetPropertyDefaultValues_Add);
@@ -96,6 +99,8 @@ struct ManagedCallbacks {
 	using FuncCSharpInstanceBridge_CallDispose = void(GD_CLR_STDCALL *)(GCHandleIntPtr, bool);
 	using FuncCSharpInstanceBridge_CallToString = void(GD_CLR_STDCALL *)(GCHandleIntPtr, String *, bool *);
 	using FuncCSharpInstanceBridge_HasMethodUnknownParams = bool(GD_CLR_STDCALL *)(GCHandleIntPtr, const StringName *);
+	using FuncCSharpInstanceBridge_SerializeState = void(GD_CLR_STDCALL *)(GCHandleIntPtr, const Dictionary *, const Dictionary *);
+	using FuncCSharpInstanceBridge_DeserializeState = void(GD_CLR_STDCALL *)(GCHandleIntPtr, const Dictionary *, const Dictionary *);
 	using FuncGCHandleBridge_FreeGCHandle = void(GD_CLR_STDCALL *)(GCHandleIntPtr);
 	using FuncDebuggingUtils_GetCurrentStackInfo = void(GD_CLR_STDCALL *)(Vector<ScriptLanguage::StackInfo> *);
 	using FuncDisposablesTracker_OnGodotShuttingDown = void(GD_CLR_STDCALL *)();
@@ -104,6 +109,8 @@ struct ManagedCallbacks {
 	FuncSignalAwaiter_SignalCallback SignalAwaiter_SignalCallback;
 	FuncDelegateUtils_InvokeWithVariantArgs DelegateUtils_InvokeWithVariantArgs;
 	FuncDelegateUtils_DelegateEquals DelegateUtils_DelegateEquals;
+	FuncDelegateUtils_TrySerializeDelegateWithGCHandle DelegateUtils_TrySerializeDelegateWithGCHandle;
+	FuncDelegateUtils_TryDeserializeDelegateWithGCHandle DelegateUtils_TryDeserializeDelegateWithGCHandle;
 	FuncScriptManagerBridge_FrameCallback ScriptManagerBridge_FrameCallback;
 	FuncScriptManagerBridge_CreateManagedForGodotObjectBinding ScriptManagerBridge_CreateManagedForGodotObjectBinding;
 	FuncScriptManagerBridge_CreateManagedForGodotObjectScriptInstance ScriptManagerBridge_CreateManagedForGodotObjectScriptInstance;
@@ -116,6 +123,7 @@ struct ManagedCallbacks {
 	FuncScriptManagerBridge_AddScriptBridge ScriptManagerBridge_AddScriptBridge;
 	FuncScriptManagerBridge_GetOrCreateScriptBridgeForPath ScriptManagerBridge_GetOrCreateScriptBridgeForPath;
 	FuncScriptManagerBridge_RemoveScriptBridge ScriptManagerBridge_RemoveScriptBridge;
+	FuncScriptManagerBridge_TryReloadRegisteredScriptWithClass ScriptManagerBridge_TryReloadRegisteredScriptWithClass;
 	FuncScriptManagerBridge_UpdateScriptClassInfo ScriptManagerBridge_UpdateScriptClassInfo;
 	FuncScriptManagerBridge_SwapGCHandleForType ScriptManagerBridge_SwapGCHandleForType;
 	FuncScriptManagerBridge_GetPropertyInfoList ScriptManagerBridge_GetPropertyInfoList;
@@ -126,6 +134,8 @@ struct ManagedCallbacks {
 	FuncCSharpInstanceBridge_CallDispose CSharpInstanceBridge_CallDispose;
 	FuncCSharpInstanceBridge_CallToString CSharpInstanceBridge_CallToString;
 	FuncCSharpInstanceBridge_HasMethodUnknownParams CSharpInstanceBridge_HasMethodUnknownParams;
+	FuncCSharpInstanceBridge_SerializeState CSharpInstanceBridge_SerializeState;
+	FuncCSharpInstanceBridge_DeserializeState CSharpInstanceBridge_DeserializeState;
 	FuncGCHandleBridge_FreeGCHandle GCHandleBridge_FreeGCHandle;
 	FuncDebuggingUtils_GetCurrentStackInfo DebuggingUtils_GetCurrentStackInfo;
 	FuncDisposablesTracker_OnGodotShuttingDown DisposablesTracker_OnGodotShuttingDown;
@@ -137,9 +147,6 @@ extern bool godot_api_cache_updated;
 
 void update_godot_api_cache(const ManagedCallbacks &p_managed_callbacks);
 
-inline void clear_godot_api_cache() {
-	managed_callbacks = ManagedCallbacks();
-}
 } // namespace GDMonoCache
 
 #undef GD_CLR_STDCALL