bpo-33540: Add block_on_close attr to socketserver (GH-6911)

Add a new block_on_close class attribute to ForkingMixIn and
ThreadingMixIn classes of socketserver to opt-in for pre-3.7 behaviour.

2 files changed, 30 insertions, 6 deletions

diff --git a/Doc/library/socketserver.rst b/Doc/library/socketserver.rst
index 5600027..1b3062d 100644
--- a/Doc/library/socketserver.rst
+++ b/Doc/library/socketserver.rst
@@ -116,10 +116,13 @@ server classes.
    only available on POSIX platforms that support :func:`~os.fork`.
 
    :meth:`socketserver.ForkingMixIn.server_close` waits until all child
-   processes complete.
+   processes complete, except if
+   :attr:`socketserver.ForkingMixIn.block_on_close` attribute is false.
 
    :meth:`socketserver.ThreadingMixIn.server_close` waits until all non-daemon
-   threads complete. Use daemonic threads by setting
+   threads complete, except if
+   :attr:`socketserver.ThreadingMixIn.block_on_close` attribute is false. Use
+   daemonic threads by setting
    :data:`ThreadingMixIn.daemon_threads` to ``True`` to not wait until threads
    complete.
 
@@ -128,6 +131,8 @@ server classes.
       :meth:`socketserver.ForkingMixIn.server_close` and
       :meth:`socketserver.ThreadingMixIn.server_close` now waits until all
       child processes and non-daemonic threads complete.
+      Add a new :attr:`socketserver.ForkingMixIn.block_on_close` class
+      attribute to opt-in for the pre-3.7 behaviour.
 
 
 .. class:: ForkingTCPServer
diff --git a/Doc/whatsnew/3.7.rst b/Doc/whatsnew/3.7.rst
index 46015af..b466e74 100644
--- a/Doc/whatsnew/3.7.rst
+++ b/Doc/whatsnew/3.7.rst
@@ -1216,6 +1216,18 @@ by default.
 (Contributed by Christian Heimes in :issue:`28134`.)
 
 
+socketserver
+------------
+
+:meth:`socketserver.ThreadingMixIn.server_close` now waits until all non-daemon
+threads complete. :meth:`socketserver.ForkingMixIn.server_close` now waits
+until all child processes complete.
+
+Add a new :attr:`socketserver.ForkingMixIn.block_on_close` class attribute to
+:class:`socketserver.ForkingMixIn` and :class:`socketserver.ThreadingMixIn`
+classes. Set the class attribute to ``False`` to get the pre-3.7 behaviour.
+
+
 sqlite3
 -------
 
@@ -2156,10 +2168,17 @@ Changes in the Python API
   and module are affected by this change. (Contributed by INADA Naoki and
   Eugene Toder in :issue:`29463`.)
 
-* :meth:`~socketserver.BaseServer.server_close` in
-  :class:`socketserver.ThreadingMixIn` and :class:`socketserver.ForkingMixIn`
-  now waits until all non-daemon threads complete.
-  (Contributed by Victor Stinner in :issue:`31233` and :issue:`31151`.)
+* :meth:`socketserver.ThreadingMixIn.server_close` now waits until all
+  non-daemon threads complete.  Set the new
+  :attr:`socketserver.ThreadingMixIn.block_on_close` class attribute to
+  ``False`` to get the pre-3.7 behaviour.
+  (Contributed by Victor Stinner in :issue:`31233` and :issue:`33540`.)
+
+* :meth:`socketserver.ForkingMixIn.server_close` now waits until all
+  child processes complete. Set the new
+  :attr:`socketserver.ForkingMixIn.block_on_close` class attribute to ``False``
+  to get the pre-3.7 behaviour.
+  (Contributed by Victor Stinner in :issue:`31151` and :issue:`33540`.)
 
 * The :func:`locale.localeconv` function now temporarily sets the ``LC_CTYPE``
   locale to the value of ``LC_NUMERIC`` in some cases.