bpo-37194: Add a new public PyObject_CallNoArgs() function (GH-13890)
Add a new public PyObject_CallNoArgs() function to the C API: call a
callable Python object without any arguments.
It is the most efficient way to call a callback without any argument.
On x86-64, for example, PyObject_CallFunctionObjArgs(func, NULL)
allocates 960 bytes on the stack per call, whereas
PyObject_CallNoArgs(func) only allocates 624 bytes per call.
It is excluded from stable ABI 3.8.
Replace private _PyObject_CallNoArg() with public
PyObject_CallNoArgs() in C extensions: _asyncio, _datetime,
_elementtree, _pickle, _tkinter and readline.
diff --git a/Include/abstract.h b/Include/abstract.h
index c226aab..f36fafb 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -141,6 +141,12 @@
#endif
+#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03090000
+/* Call a callable Python object without any arguments */
+PyAPI_FUNC(PyObject *) PyObject_CallNoArgs(PyObject *func);
+#endif
+
+
/* Call a callable Python object 'callable' with arguments given by the
tuple 'args' and keywords arguments given by the dictionary 'kwargs'.
diff --git a/Include/cpython/abstract.h b/Include/cpython/abstract.h
index d036912..415f3e1 100644
--- a/Include/cpython/abstract.h
+++ b/Include/cpython/abstract.h
@@ -144,7 +144,9 @@
return _PyObject_Vectorcall(func, args, (size_t)nargs, NULL);
}
-/* Call a callable without any arguments */
+/* Call a callable without any arguments
+ Private static inline function variant of public function
+ PyObject_CallNoArgs(). */
static inline PyObject *
_PyObject_CallNoArg(PyObject *func) {
return _PyObject_Vectorcall(func, NULL, 0, NULL);