bpo-42294: Add borrowed/strong reference to doc glossary (GH-23206)
Add "borrowed reference" and "strong reference" to the documentation
glossary.
Enhance also Py_INCREF() and Py_NewRef() documentation.
diff --git a/Doc/c-api/refcounting.rst b/Doc/c-api/refcounting.rst
index b15c0e6..391907c 100644
--- a/Doc/c-api/refcounting.rst
+++ b/Doc/c-api/refcounting.rst
@@ -13,10 +13,14 @@
.. c:function:: void Py_INCREF(PyObject *o)
- Increment the reference count for object *o*. The object must not be ``NULL``; if
- you aren't sure that it isn't ``NULL``, use :c:func:`Py_XINCREF`.
+ Increment the reference count for object *o*.
- See also :c:func:`Py_NewRef`.
+ This function is usually used to convert a :term:`borrowed reference` to a
+ :term:`strong reference` in-place. The :c:func:`Py_NewRef` function can be
+ used to create a new :term:`strong reference`.
+
+ The object must not be ``NULL``; if you aren't sure that it isn't
+ ``NULL``, use :c:func:`Py_XINCREF`.
.. c:function:: void Py_XINCREF(PyObject *o)
@@ -29,9 +33,14 @@
.. c:function:: PyObject* Py_NewRef(PyObject *o)
- Increment the reference count of the object *o* and return the object *o*.
+ Create a new :term:`strong reference` to an object: increment the reference
+ count of the object *o* and return the object *o*.
- The object *o* must not be ``NULL``.
+ When the :term:`strong reference` is no longer needed, :c:func:`Py_DECREF`
+ should be called on it to decrement the object reference count.
+
+ The object *o* must not be ``NULL``; use :c:func:`Py_XNewRef` if *o* can be
+ ``NULL``.
For example::
@@ -42,6 +51,8 @@
self->attr = Py_NewRef(obj);
+ See also :c:func:`Py_INCREF`.
+
.. versionadded:: 3.10
@@ -56,10 +67,16 @@
.. c:function:: void Py_DECREF(PyObject *o)
- Decrement the reference count for object *o*. The object must not be ``NULL``; if
- you aren't sure that it isn't ``NULL``, use :c:func:`Py_XDECREF`. If the reference
- count reaches zero, the object's type's deallocation function (which must not be
- ``NULL``) is invoked.
+ Decrement the reference count for object *o*.
+
+ If the reference count reaches zero, the object's type's deallocation
+ function (which must not be ``NULL``) is invoked.
+
+ This function is usually used to delete a :term:`strong reference` before
+ exiting its scope.
+
+ The object must not be ``NULL``; if you aren't sure that it isn't ``NULL``,
+ use :c:func:`Py_XDECREF`.
.. warning::