bpo-37340: Remove PyMethod_ClearFreeList() and PyCFunction_ClearFreeList() (GH-17284)

Remove PyMethod_ClearFreeList() and PyCFunction_ClearFreeList()
functions: the free lists of bound method objects have been removed.

Remove also _PyMethod_Fini() and _PyCFunction_Fini() functions.

Author: vstinner

Doc/whatsnew/3.9.rst

@@ -217,6 +217,7 @@ Build and C API Changes
   ``PyThreadState.recursion_depth`` field. Remove ``_Py_CheckRecursionLimit``
   from the stable ABI.
   (Contributed by Victor Stinner in :issue:`38644`.)
+
 * Add a new public :c:func:`PyObject_CallNoArgs` function to the C API, which
   calls a callable Python object without any arguments. It is the most efficient
   way to call a callable Python object without any argument.
@@ -230,6 +231,10 @@ Build and C API Changes
   ``pyfpe.h`` from ``Py_LIMITED_API`` (stable API).
   (Contributed by Victor Stinner in :issue:`38835`.)
 
+* Remove ``PyMethod_ClearFreeList()`` and ``PyCFunction_ClearFreeList()``
+  functions: the free lists of bound method objects have been removed.
+  (Contributed by Inada Naoki and Victor Stinner in :issue:`37340`.)
+
 
 Deprecated
 ==========

Include/classobject.h

@@ -33,8 +33,6 @@ PyAPI_FUNC(PyObject *) PyMethod_Self(PyObject *);
 #define PyMethod_GET_SELF(meth) \
         (((PyMethodObject *)meth) -> im_self)
 
-PyAPI_FUNC(int) PyMethod_ClearFreeList(void);
-
 typedef struct {
     PyObject_HEAD
     PyObject *func;

Include/internal/pycore_pylifecycle.h

@@ -59,9 +59,7 @@ extern PyStatus _PyGC_Init(PyThreadState *tstate);
 
 /* Various internal finalizers */
 
-extern void _PyMethod_Fini(void);
 extern void _PyFrame_Fini(void);
-extern void _PyCFunction_Fini(void);
 extern void _PyDict_Fini(void);
 extern void _PyTuple_Fini(void);
 extern void _PyList_Fini(void);

Include/methodobject.h

@@ -97,8 +97,6 @@ typedef struct {
 } PyCFunctionObject;
 #endif
 
-PyAPI_FUNC(int) PyCFunction_ClearFreeList(void);
-
 #ifdef __cplusplus
 }
 #endif

Misc/NEWS.d/next/C API/2019-11-20-11-08-06.bpo-37340.JBQJMS.rst

@@ -0,0 +1,2 @@
+Remove ``PyMethod_ClearFreeList()`` and ``PyCFunction_ClearFreeList()``
+functions: the free lists of bound method objects have been removed.

Modules/gcmodule.c

@@ -1029,9 +1029,7 @@ delete_garbage(PyThreadState *tstate, GCState *gcstate,
 static void
 clear_freelists(void)
 {
-    (void)PyMethod_ClearFreeList();
     (void)PyFrame_ClearFreeList();
-    (void)PyCFunction_ClearFreeList();
     (void)PyTuple_ClearFreeList();
     (void)PyUnicode_ClearFreeList();
     (void)PyFloat_ClearFreeList();

Objects/classobject.c

@@ -371,20 +371,6 @@ PyTypeObject PyMethod_Type = {
     method_new,                                 /* tp_new */
 };
 
-/* Clear out the free list */
-
-int
-PyMethod_ClearFreeList(void)
-{
-    return 0;
-}
-
-void
-_PyMethod_Fini(void)
-{
-    (void)PyMethod_ClearFreeList();
-}
-
 /* ------------------------------------------------------------------------
  * instance method
  */

Objects/methodobject.c

@@ -313,21 +313,6 @@ PyTypeObject PyCFunction_Type = {
     0,                                          /* tp_dict */
 };
 
-/* Clear out the free list */
-
-int
-PyCFunction_ClearFreeList(void)
-{
-    return 0;
-}
-
-void
-_PyCFunction_Fini(void)
-{
-    (void)PyCFunction_ClearFreeList();
-}
-
-
 /* Vectorcall functions for each of the PyCFunction calling conventions,
  * except for METH_VARARGS (possibly combined with METH_KEYWORDS) which
  * doesn't use vectorcall.

Python/pylifecycle.c

@@ -1173,9 +1173,7 @@ finalize_interp_types(PyThreadState *tstate, int is_main_interp)
 {
     if (is_main_interp) {
         /* Sundry finalizers */
-        _PyMethod_Fini();
         _PyFrame_Fini();
-        _PyCFunction_Fini();
         _PyTuple_Fini();
         _PyList_Fini();
         _PySet_Fini();