gh-103673: Add missing ForkingUnixStreamServer and ForkingUnixDatagramServer socketservers (#103674)

sockserver gains ForkingUnixStreamServer and ForkingUnixDatagramServer classes for consistency with all of the others. Ironically these existed but were buried in our test suite.

Addresses #103673 

<!-- gh-issue-number: gh-103673 -->
* Issue: gh-103673
<!-- /gh-issue-number -->

---------

Co-authored-by: Gregory P. Smith <greg@krypto.org>
Co-authored-by: Nikita Sobolev <mail@sobolevn.me>

Doc/library/socketserver.rst

@@ -140,9 +140,16 @@ server is the address family.
            ForkingUDPServer
            ThreadingTCPServer
            ThreadingUDPServer
+           ForkingUnixStreamServer
+           ForkingUnixDatagramServer
+           ThreadingUnixStreamServer
+           ThreadingUnixDatagramServer
 
    These classes are pre-defined using the mix-in classes.
 
+.. versionadded:: 3.12
+   The ``ForkingUnixStreamServer`` and ``ForkingUnixDatagramServer`` classes
+   were added.
 
 To implement a service, you must derive a class from :class:`BaseRequestHandler`
 and redefine its :meth:`~BaseRequestHandler.handle` method.

Lib/socketserver.py

@@ -141,6 +141,8 @@ if hasattr(socket, "AF_UNIX"):
     __all__.extend(["UnixStreamServer","UnixDatagramServer",
                     "ThreadingUnixStreamServer",
                     "ThreadingUnixDatagramServer"])
+    if hasattr(os, "fork"):
+        __all__.extend(["ForkingUnixStreamServer", "ForkingUnixDatagramServer"])
 
 # poll/select have the advantage of not requiring any extra file descriptor,
 # contrarily to epoll/kqueue (also, they require a single syscall).
@@ -727,6 +729,11 @@ if hasattr(socket, 'AF_UNIX'):
 
     class ThreadingUnixDatagramServer(ThreadingMixIn, UnixDatagramServer): pass
 
+    if hasattr(os, "fork"):
+        class ForkingUnixStreamServer(ForkingMixIn, UnixStreamServer): pass
+
+        class ForkingUnixDatagramServer(ForkingMixIn, UnixDatagramServer): pass
+
 class BaseRequestHandler:
 
     """Base class for request handler classes.

Lib/test/test_socketserver.py

@@ -47,14 +47,6 @@ def receive(sock, n, timeout=test.support.SHORT_TIMEOUT):
     else:
         raise RuntimeError("timed out on %r" % (sock,))
 
-if HAVE_UNIX_SOCKETS and HAVE_FORKING:
-    class ForkingUnixStreamServer(socketserver.ForkingMixIn,
-                                  socketserver.UnixStreamServer):
-        pass
-
-    class ForkingUnixDatagramServer(socketserver.ForkingMixIn,
-                                    socketserver.UnixDatagramServer):
-        pass
 
 @test.support.requires_fork()
 @contextlib.contextmanager
@@ -211,7 +203,7 @@ class SocketServerTest(unittest.TestCase):
     @requires_forking
     def test_ForkingUnixStreamServer(self):
         with simple_subprocess(self):
-            self.run_server(ForkingUnixStreamServer,
+            self.run_server(socketserver.ForkingUnixStreamServer,
                             socketserver.StreamRequestHandler,
                             self.stream_examine)
 
@@ -247,7 +239,7 @@ class SocketServerTest(unittest.TestCase):
     @requires_unix_sockets
     @requires_forking
     def test_ForkingUnixDatagramServer(self):
-        self.run_server(ForkingUnixDatagramServer,
+        self.run_server(socketserver.ForkingUnixDatagramServer,
                         socketserver.DatagramRequestHandler,
                         self.dgram_examine)
 

Misc/ACKS

@@ -160,6 +160,7 @@ Brice Berna
 Olivier Bernard
 Vivien Bernet-Rollande
 Maxwell Bernstein
+Jay Berry
 Eric Beser
 Steven Bethard
 Stephen Bevan

Misc/NEWS.d/next/Library/2023-04-22-02-41-06.gh-issue-103673.oE7S_k.rst

@@ -0,0 +1,2 @@
+:mod:`socketserver` gains ``ForkingUnixStreamServer`` and
+``ForkingUnixDatagramServer`` classes. Patch by Jay Berry.