Detach socket in create_server, create_connection, and other APIs

Author: 1st1

Diff for: asyncio/base_events.py

@@ -87,6 +87,12 @@ def _set_reuseport(sock):
                              'SO_REUSEPORT defined but not implemented.')
 
 
+def _copy_and_detach_socket(sock):
+    new_sock = socket.socket(sock.family, sock.type, sock.proto, sock.fileno())
+    sock.detach()
+    return new_sock
+
+
 # Linux's sock.type is a bitmask that can include extra info about socket.
 _SOCKET_TYPE_MASK = 0
 if hasattr(socket, 'SOCK_NONBLOCK'):
@@ -768,9 +774,11 @@ def create_connection(self, protocol_factory, host=None, port=None, *,
                     raise OSError('Multiple exceptions: {}'.format(
                         ', '.join(str(exc) for exc in exceptions)))
 
-        elif sock is None:
-            raise ValueError(
-                'host and port was not specified and no sock specified')
+        else:
+            if sock is None:
+                raise ValueError(
+                    'host and port was not specified and no sock specified')
+            sock = _copy_and_detach_socket(sock)
 
         transport, protocol = yield from self._create_connection_transport(
             sock, protocol_factory, ssl, server_hostname)
@@ -827,6 +835,7 @@ def create_datagram_endpoint(self, protocol_factory,
                 raise ValueError(
                     'socket modifier keyword arguments can not be used '
                     'when sock is specified. ({})'.format(problems))
+            sock = _copy_and_detach_socket(sock)
             sock.setblocking(False)
             r_addr = None
         else:
@@ -1024,6 +1033,7 @@ def create_server(self, protocol_factory, host=None, port=None,
         else:
             if sock is None:
                 raise ValueError('Neither host/port nor sock were specified')
+            sock = _copy_and_detach_socket(sock)
             sockets = [sock]
 
         server = Server(self, sockets)
@@ -1045,6 +1055,7 @@ def connect_accepted_socket(self, protocol_factory, sock, *, ssl=None):
         This method is a coroutine.  When completed, the coroutine
         returns a (transport, protocol) pair.
         """
+        sock = _copy_and_detach_socket(sock)
         transport, protocol = yield from self._create_connection_transport(
             sock, protocol_factory, ssl, '', server_side=True)
         if self._debug:

Diff for: tests/test_events.py

@@ -1240,11 +1240,12 @@ def connection_made(self, transport):
         sock_ob = socket.socket(type=socket.SOCK_STREAM)
         sock_ob.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
         sock_ob.bind(('0.0.0.0', 0))
+        sock_ob_fd = sock_ob.fileno()
 
         f = self.loop.create_server(TestMyProto, sock=sock_ob)
         server = self.loop.run_until_complete(f)
         sock = server.sockets[0]
-        self.assertIs(sock, sock_ob)
+        self.assertEqual(sock.fileno(), sock_ob_fd)
 
         host, port = sock.getsockname()
         self.assertEqual(host, '0.0.0.0')

Diff for: tests/test_streams.py

@@ -582,7 +582,7 @@ def start(self):
                     asyncio.start_server(self.handle_client,
                                          sock=sock,
                                          loop=self.loop))
-                return sock.getsockname()
+                return self.server.sockets[0].getsockname()
 
             def handle_client_callback(self, client_reader, client_writer):
                 self.loop.create_task(self.handle_client(client_reader,