support await

Author: blueloveTH

demo/MyScript.py

@@ -29,6 +29,19 @@ def _ready(self):
 		print('==> vector2:', Vector2(1.5, 2.5).angle())
 
 		self.health_changed.emit(100, 200)
+		start_coroutine(self.coro(3))
+
+	def coro_one_sec(self, i: int):
+		print(f'  coro_one_sec({i}) start')
+		yield self.owner.get_tree().create_timer(1).timeout
+		yield 3
+		print(f'  coro_one_sec({i}) end')
+
+	def coro(self, secs: int):
+		print(f'coro({secs}) start')
+		for i in range(secs):
+			yield from self.coro_one_sec(i)
+		print(f'coro({secs}) end')
 
 	def _process(self, delta: float) -> None:
 		if Input.is_key_pressed(KEY_SPACE):

demo/main.tscn

@@ -1,16 +1,16 @@
-[gd_scene load_steps=3 format=3 uid="uid://tudbnvddbxp6"]
+[gd_scene format=3 uid="uid://tudbnvddbxp6"]
 
 [ext_resource type="Script" uid="uid://dof0ku5rrw77i" path="res://new_script.gd" id="1_ig7tw"]
 [ext_resource type="Script" uid="uid://drm3k4ac6d87p" path="res://MyScript.py" id="2_0xm2m"]
 
-[node name="root" type="Node2D"]
+[node name="root" type="Node2D" unique_id=166675096]
 
-[node name="gds_node" type="Node" parent="." node_paths=PackedStringArray("y")]
+[node name="gds_node" type="Node" parent="." unique_id=1026672657 node_paths=PackedStringArray("y")]
 script = ExtResource("1_ig7tw")
 y = NodePath("../py_node")
 z = 4.8
 
-[node name="py_node" type="Node" parent="." node_paths=PackedStringArray("y")]
+[node name="py_node" type="Node" parent="." unique_id=420174823 node_paths=PackedStringArray("y")]
 script = ExtResource("2_0xm2m")
 z = 4.8
 y = NodePath("../gds_node")

src/lang/Bindings.cpp

@@ -13,6 +13,60 @@ namespace pkpy {
 
 void setup_bindings_generated();
 
+static bool call_next_for_coroutine(py_i64 id);
+
+static void call_next_for_coroutine_no_error(py_i64 id) {
+	py_Ref p0 = py_peek(0);
+	bool ok = call_next_for_coroutine(id);
+	if(!ok) log_python_error_and_clearexc(p0);
+}
+
+static bool call_next_for_coroutine(py_i64 id) {
+	std::thread::id current_thread_id = std::this_thread::get_id();
+	if (current_thread_id != pyctx()->main_thread_id) {
+		ERR_PRINT("coroutine can only be resumed in the main thread");
+		std::abort();
+	}
+	py_ItemRef gen = pythreadctx()->pending_coroutines.getptr(id);
+	if(gen == NULL) {
+		return RuntimeError("cannot find coroutine by id: %i", id);
+	}
+	int res = py_next(gen);
+	if(res == 1) {
+		if(py_retval()->type != pyctx()->tp_Variant) {
+			return TypeError("coroutine yielded value must be 'godot.Signal', got '%t'", py_typeof(py_retval()));
+		}
+		Variant v = to_variant_exact(py_retval());
+		if(v.get_type() != Variant::SIGNAL) {
+			CharString type_name = Variant::get_type_name(v.get_type()).utf8();
+			return TypeError("coroutine yielded value must be 'godot.Signal', got '%s'", type_name.get_data());
+		}
+		Signal signal = v;
+		Callable callable = callable_mp_static(call_next_for_coroutine_no_error);
+		signal.connect(callable.bind(id), Object::CONNECT_ONE_SHOT | Object::CONNECT_DEFERRED);
+		py_newnone(py_retval());
+		return true;
+	} else if (res == -1) {
+		pythreadctx()->pending_coroutines.erase(id);
+		return false;	// error
+	} else {
+		// generator finished
+		pythreadctx()->pending_coroutines.erase(id);
+		py_newnone(py_retval());
+		return true;
+	}
+}
+
+static void setup_awaitables() {
+	py_bindfunc(pyctx()->godot, "start_coroutine", [](int argc, py_Ref argv) -> bool {
+		PY_CHECK_ARGC(1);
+		PY_CHECK_ARG_TYPE(0, tp_generator);
+		py_i64 id = argv[0]._i64;
+		pythreadctx()->pending_coroutines[id] = argv[0];
+		return call_next_for_coroutine(id);
+	});
+}
+
 static void setup_exports() {
 	// export
 	pyctx()->tp_DefineStatement = py_newtype("_DefineStatement", tp_object, pyctx()->godot, [](void *ud) {
@@ -304,6 +358,9 @@ void setup_python_bindings() {
 #undef DEF_UNARY_OP
 
 	setup_bindings_generated();
+
+	setup_awaitables();
+
 	printf("==> setup_python_bindings() done!\n");
 }
 

src/lang/Common.hpp

@@ -105,6 +105,7 @@ struct GDNativeClass {
 struct PythonThreadContext {
 	Vector<Callable> pending_callables;
 	Vector<std::pair<GDNativeClass, py_Name>> pending_nativecalls;
+	HashMap<py_i64, py_TValue> pending_coroutines;
 };
 
 struct DefineStatement {

src/lang/PythonScriptInstance.cpp

@@ -216,6 +216,9 @@ void PythonScriptInstance::gc_mark_instances(void (*f)(py_Ref val, void *ctx), v
 		PythonScriptInstance *instance = kv.value;
 		f(&instance->py, ctx);
 	}
+	for(auto &kv: pythreadctx()->pending_coroutines) {
+		f(&kv.value, ctx);
+	}
 }
 
 HashMap<Object *, PythonScriptInstance *> PythonScriptInstance::known_instances;

stubgen/map.py

@@ -541,7 +541,7 @@ def gen_alias_pyi_writer(gdt_all_in_one: GodotInOne, pyi_writer: Writer) -> Writ
 
 def gen_init_pyi_writer(gdt_all_in_one: GodotInOne, pyi_writer: Writer, global_variant_classes: list[str]) -> Writer:
     pyi_writer.write(
-        """\
+        '''\
 from . import classes
 
 class PythonScriptInstance[T: classes.Object]:
@@ -553,7 +553,14 @@ def export[T](cls: type[T], default=None) -> T: ...
 def export_range[T: int | float](min: T, max: T, step: T, default: T | None = None) -> T: ...
 def signal(*args: str) -> classes.Signal: ...
 def load(path: str) -> classes.Resource: ...
-"""
+
+def start_coroutine(gen) -> None:
+    """Start a coroutine. The argument should be a `generator` object.
+
+    - To await a `godot.Signal`, use `yield your_signal`
+    - To await another coroutine, use `yield from another_coroutine()`
+    """
+'''
     )
 
     writer = pyi_writer