Issue #24400: Introduce a distinct type for 'async def' coroutines.
Summary of changes:
1. Coroutines now have a distinct, separate from generators
type at the C level: PyGen_Type, and a new typedef PyCoroObject.
PyCoroObject shares the initial segment of struct layout with
PyGenObject, making it possible to reuse existing generators
machinery. The new type is exposed as 'types.CoroutineType'.
As a consequence of having a new type, CO_GENERATOR flag is
no longer applied to coroutines.
2. Having a separate type for coroutines made it possible to add
an __await__ method to the type. Although it is not used by the
interpreter (see details on that below), it makes coroutines
naturally (without using __instancecheck__) conform to
collections.abc.Coroutine and collections.abc.Awaitable ABCs.
[The __instancecheck__ is still used for generator-based
coroutines, as we don't want to add __await__ for generators.]
3. Add new opcode: GET_YIELD_FROM_ITER. The opcode is needed to
allow passing native coroutines to the YIELD_FROM opcode.
Before this change, 'yield from o' expression was compiled to:
(o)
GET_ITER
LOAD_CONST
YIELD_FROM
Now, we use GET_YIELD_FROM_ITER instead of GET_ITER.
The reason for adding a new opcode is that GET_ITER is used
in some contexts (such as 'for .. in' loops) where passing
a coroutine object is invalid.
4. Add two new introspection functions to the inspec module:
getcoroutinestate(c) and getcoroutinelocals(c).
5. inspect.iscoroutine(o) is updated to test if 'o' is a native
coroutine object. Before this commit it used abc.Coroutine,
and it was requested to update inspect.isgenerator(o) to use
abc.Generator; it was decided, however, that inspect functions
should really be tailored for checking for native types.
6. sys.set_coroutine_wrapper(w) API is updated to work with only
native coroutines. Since types.coroutine decorator supports
any type of callables now, it would be confusing that it does
not work for all types of coroutines.
7. Exceptions logic in generators C implementation was updated
to raise clearer messages for coroutines:
Before: TypeError("generator raised StopIteration")
After: TypeError("coroutine raised StopIteration")
diff --git a/Include/genobject.h b/Include/genobject.h
index ee0b130..4c71861 100644
--- a/Include/genobject.h
+++ b/Include/genobject.h
@@ -10,27 +10,26 @@
struct _frame; /* Avoid including frameobject.h */
+/* _PyGenObject_HEAD defines the initial segment of generator
+ and coroutine objects. */
+#define _PyGenObject_HEAD(prefix) \
+ PyObject_HEAD \
+ /* Note: gi_frame can be NULL if the generator is "finished" */ \
+ struct _frame *prefix##_frame; \
+ /* True if generator is being executed. */ \
+ char prefix##_running; \
+ /* The code object backing the generator */ \
+ PyObject *prefix##_code; \
+ /* List of weak reference. */ \
+ PyObject *prefix##_weakreflist; \
+ /* Name of the generator. */ \
+ PyObject *prefix##_name; \
+ /* Qualified name of the generator. */ \
+ PyObject *prefix##_qualname;
+
typedef struct {
- PyObject_HEAD
/* The gi_ prefix is intended to remind of generator-iterator. */
-
- /* Note: gi_frame can be NULL if the generator is "finished" */
- struct _frame *gi_frame;
-
- /* True if generator is being executed. */
- char gi_running;
-
- /* The code object backing the generator */
- PyObject *gi_code;
-
- /* List of weak reference. */
- PyObject *gi_weakreflist;
-
- /* Name of the generator. */
- PyObject *gi_name;
-
- /* Qualified name of the generator. */
- PyObject *gi_qualname;
+ _PyGenObject_HEAD(gi)
} PyGenObject;
PyAPI_DATA(PyTypeObject) PyGen_Type;
@@ -38,12 +37,6 @@
#define PyGen_Check(op) PyObject_TypeCheck(op, &PyGen_Type)
#define PyGen_CheckExact(op) (Py_TYPE(op) == &PyGen_Type)
-#define PyGen_CheckCoroutineExact(op) (PyGen_CheckExact(op) && \
- (((PyCodeObject*) \
- ((PyGenObject*)op)->gi_code) \
- ->co_flags & (CO_ITERABLE_COROUTINE | \
- CO_COROUTINE)))
-
PyAPI_FUNC(PyObject *) PyGen_New(struct _frame *);
PyAPI_FUNC(PyObject *) PyGen_NewWithQualName(struct _frame *,
PyObject *name, PyObject *qualname);
@@ -52,7 +45,21 @@
PyObject *_PyGen_Send(PyGenObject *, PyObject *);
PyAPI_FUNC(void) _PyGen_Finalize(PyObject *self);
-PyObject *_PyGen_GetAwaitableIter(PyObject *o);
+#ifndef Py_LIMITED_API
+typedef struct {
+ _PyGenObject_HEAD(cr)
+} PyCoroObject;
+
+PyAPI_DATA(PyTypeObject) PyCoro_Type;
+PyAPI_DATA(PyTypeObject) _PyCoroWrapper_Type;
+
+#define PyCoro_CheckExact(op) (Py_TYPE(op) == &PyCoro_Type)
+PyObject *_PyCoro_GetAwaitableIter(PyObject *o);
+PyAPI_FUNC(PyObject *) PyCoro_New(struct _frame *,
+ PyObject *name, PyObject *qualname);
+#endif
+
+#undef _PyGenObject_HEAD
#ifdef __cplusplus
}