Issue #28174: Handle when SO_REUSEPORT isn't properly supported (asyncio)

Patch by Seth Michael Larson.

1 files changed, 13 insertions, 12 deletions

diff --git a/Lib/asyncio/base_events.py b/Lib/asyncio/base_events.py
index 8d926dc..03935ea 100644
--- a/Lib/asyncio/base_events.py
+++ b/Lib/asyncio/base_events.py
@@ -76,6 +76,17 @@ def _format_pipe(fd):
         return repr(fd)
 
 
+def _set_reuseport(sock):
+    if not hasattr(socket, 'SO_REUSEPORT'):
+        raise ValueError('reuse_port not supported by socket module')
+    else:
+        try:
+            sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+        except OSError:
+            raise ValueError('reuse_port not supported by socket module, '
+                             'SO_REUSEPORT defined but not implemented.')
+
+
 # Linux's sock.type is a bitmask that can include extra info about socket.
 _SOCKET_TYPE_MASK = 0
 if hasattr(socket, 'SOCK_NONBLOCK'):
@@ -873,12 +884,7 @@ class BaseEventLoop(events.AbstractEventLoop):
                         sock.setsockopt(
                             socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
                     if reuse_port:
-                        if not hasattr(socket, 'SO_REUSEPORT'):
-                            raise ValueError(
-                                'reuse_port not supported by socket module')
-                        else:
-                            sock.setsockopt(
-                                socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+                        _set_reuseport(sock)
                     if allow_broadcast:
                         sock.setsockopt(
                             socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
@@ -1001,12 +1007,7 @@ class BaseEventLoop(events.AbstractEventLoop):
                         sock.setsockopt(
                             socket.SOL_SOCKET, socket.SO_REUSEADDR, True)
                     if reuse_port:
-                        if not hasattr(socket, 'SO_REUSEPORT'):
-                            raise ValueError(
-                                'reuse_port not supported by socket module')
-                        else:
-                            sock.setsockopt(
-                                socket.SOL_SOCKET, socket.SO_REUSEPORT, True)
+                        _set_reuseport(sock)
                     # Disable IPv4/IPv6 dual stack support (enabled by
                     # default on Linux) which makes a single socket
                     # listen on both address families.