gh-127119: Remove check on accidental deallocation of immortal objects for free-threaded build

Misc/NEWS.d/next/Core_and_Builtins/2024-11-22-07-58-00.gh-issue-127119.p9Yv4U.rst

@@ -0,0 +1 @@
+Slightly optimize the :class:`int` deallocator by removing a redundant check.

Objects/boolobject.c

@@ -159,11 +159,15 @@ static PyNumberMethods bool_as_number = {
 static void
 bool_dealloc(PyObject *boolean)
 {
+#ifndef Py_GIL_DISABLED
     /* This should never get called, but we also don't want to SEGV if
      * we accidentally decref Booleans out of existence. Instead,
      * since bools are immortal, re-set the reference count.
+     *
+     * See PEP 683, section Accidental De-Immortalizing for details
      */
     _Py_SetImmortal(boolean);
+#endif
 }
 
 /* The type object for bool.  Note that this cannot be subclassed! */

Objects/longobject.c

@@ -3614,9 +3614,12 @@ long_richcompare(PyObject *self, PyObject *other, int op)
 static void
 long_dealloc(PyObject *self)
 {
+#ifndef Py_GIL_DISABLED
     /* This should never get called, but we also don't want to SEGV if
      * we accidentally decref small Ints out of existence. Instead,
      * since small Ints are immortal, re-set the reference count.
+     *
+     * See PEP 683, section Accidental De-Immortalizing for details
      */
     PyLongObject *pylong = (PyLongObject*)self;
     if (pylong && _PyLong_IsCompact(pylong)) {
@@ -3629,6 +3632,7 @@ long_dealloc(PyObject *self)
             }
         }
     }
+#endif
     Py_TYPE(self)->tp_free(self);
 }
 

Objects/object.c

@@ -2015,11 +2015,15 @@ none_repr(PyObject *op)
 static void
 none_dealloc(PyObject* none)
 {
+#ifndef Py_GIL_DISABLED
     /* This should never get called, but we also don't want to SEGV if
-     * we accidentally decref None out of existence. Instead,
-     * since None is an immortal object, re-set the reference count.
+     * we accidentally decref NotImplemented out of existence. Instead,
+     * since Notimplemented is an immortal object, re-set the reference count.
+     *
+     * See PEP 683, section Accidental De-Immortalizing for details
      */
     _Py_SetImmortal(none);
+#endif
 }
 
 static PyObject *
@@ -2161,11 +2165,15 @@ notimplemented_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 static void
 notimplemented_dealloc(PyObject *notimplemented)
 {
+#ifndef Py_GIL_DISABLED
     /* This should never get called, but we also don't want to SEGV if
      * we accidentally decref NotImplemented out of existence. Instead,
      * since Notimplemented is an immortal object, re-set the reference count.
+     *
+     * See PEP 683, section Accidental De-Immortalizing for details
      */
     _Py_SetImmortal(notimplemented);
+#endif
 }
 
 static int

Objects/sliceobject.c

@@ -34,11 +34,15 @@ ellipsis_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 static void
 ellipsis_dealloc(PyObject *ellipsis)
 {
+#ifndef Py_GIL_DISABLED
     /* This should never get called, but we also don't want to SEGV if
-     * we accidentally decref Ellipsis out of existence. Instead,
-     * since Ellipsis is an immortal object, re-set the reference count.
+     * we accidentally decref NotImplemented out of existence. Instead,
+     * since Notimplemented is an immortal object, re-set the reference count.
+     *
+     * See PEP 683, section Accidental De-Immortalizing for details
      */
     _Py_SetImmortal(ellipsis);
+#endif
 }
 
 static PyObject *

Objects/typevarobject.c

@@ -91,11 +91,15 @@ nodefault_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
 static void
 nodefault_dealloc(PyObject *nodefault)
 {
+#ifndef Py_GIL_DISABLED
     /* This should never get called, but we also don't want to SEGV if
-     * we accidentally decref NoDefault out of existence. Instead,
-     * since NoDefault is an immortal object, re-set the reference count.
+     * we accidentally decref NotImplemented out of existence. Instead,
+     * since Notimplemented is an immortal object, re-set the reference count.
+     *
+     * See PEP 683, section Accidental De-Immortalizing for details
      */
     _Py_SetImmortal(nodefault);
+#endif
 }
 
 PyDoc_STRVAR(nodefault_doc,