Merge 3.6 (issue #28091)

1 files changed, 36 insertions, 0 deletions

diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index f8ef83a45d..54b99e0fd9 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -603,6 +603,24 @@ always available.
    .. versionchanged:: 3.6
       Added *platform_version*
 
+
+.. function:: get_asyncgen_hooks()
+
+   Returns an *asyncgen_hooks* object, which is similar to a
+   :class:`~collections.namedtuple` of the form `(firstiter, finalizer)`,
+   where *firstiter* and *finalizer* are expected to be either ``None`` or
+   functions which take an :term:`asynchronous generator iterator` as an
+   argument, and are used to schedule finalization of an asychronous
+   generator by an event loop.
+
+   .. versionadded:: 3.6
+      See :pep:`525` for more details.
+
+   .. note::
+      This function has been added on a provisional basis (see :pep:`411`
+      for details.)
+
+
 .. function:: get_coroutine_wrapper()
 
    Returns ``None``, or a wrapper set by :func:`set_coroutine_wrapper`.
@@ -1107,6 +1125,24 @@ always available.
       implementation platform, rather than part of the language definition, and
       thus may not be available in all Python implementations.
 
+.. function:: set_asyncgen_hooks(firstiter, finalizer)
+
+   Accepts two optional keyword arguments which are callables that accept an
+   :term:`asynchronous generator iterator` as an argument. The *firstiter*
+   callable will be called when an asynchronous generator is iterated for the
+   first time. The *finalizer* will be called when an asynchronous generator
+   is about to be garbage collected.
+
+   .. versionadded:: 3.6
+      See :pep:`525` for more details, and for a reference example of a
+      *finalizer* method see the implementation of
+      ``asyncio.Loop.shutdown_asyncgens`` in
+      :source:`Lib/asyncio/base_events.py`
+
+   .. note::
+      This function has been added on a provisional basis (see :pep:`411`
+      for details.)
+
 
 .. function:: set_coroutine_wrapper(wrapper)