[Python-checkins] Re-add `reuse_address` parameter to `create_server` (GH-29733)

[asvetlov]

https://github.com/python/cpython/commit/f3c16a5e72aaf06bec863fa3a172f3deaa491bc9
commit: f3c16a5e72aaf06bec863fa3a172f3deaa491bc9
branch: main
author: Jim Crist-Harif <jcristharif at gmail.com>
committer: asvetlov <andrew.svetlov at gmail.com>
date: 2021-12-12T11:47:01+02:00
summary:

Re-add `reuse_address` parameter to `create_server` (GH-29733)

This parameter was accidentally removed when fixing
https://bugs.python.org/issue45129, this reverts the unnecessary changes
there.

Co-authored-by: Andrew Svetlov <andrew.svetlov at gmail.com>

files:
M Lib/asyncio/base_events.py

diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py
index cfaf082587bb2..cbf6d5db0a002 100644
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
@@ -1394,6 +1394,7 @@ async def create_server(
             sock=None,
             backlog=100,
             ssl=None,
+            reuse_address=None,
             reuse_port=None,
             ssl_handshake_timeout=None,
             start_serving=True):
@@ -1424,6 +1425,8 @@ async def create_server(
                 raise ValueError(
                     'host/port and sock can not be specified at the same time')
 
+            if reuse_address is None:
+                reuse_address = os.name == "posix" and sys.platform != "cygwin"
             sockets = []
             if host == '':
                 hosts = [None]
@@ -1453,6 +1456,9 @@ async def create_server(
                                            af, socktype, proto, exc_info=True)
                         continue
                     sockets.append(sock)
+                    if reuse_address:
+                        sock.setsockopt(
+                            socket.SOL_SOCKET, socket.SO_REUSEADDR, True)
                     if reuse_port:
                         _set_reuseport(sock)
                     # Disable IPv4/IPv6 dual stack support (enabled by