Get metadata flags test working

src/python/grpcio_tests/tests/unit/_metadata_flags_test.py

@@ -25,7 +25,7 @@ import grpc
 from tests.unit import test_common
 from tests.unit.framework.common import test_constants
 import tests.unit.framework.common
-from tests.unit.framework.common import listening_socket
+from tests.unit.framework.common import bound_socket
 
 _UNARY_UNARY = '/test/UnaryUnary'
 _UNARY_STREAM = '/test/UnaryStream'
@@ -123,7 +123,7 @@ class _GenericHandler(grpc.GenericRpcHandler):
 def create_dummy_channel():
     """Creating dummy channels is a workaround for retries"""
     # _, addr = get_free_loopback_tcp_port()
-    with listening_socket() as host, port:
+    with bound_socket() as (host, port):
         return grpc.insecure_channel('{}:{}'.format(host, port))
 
 
@@ -224,7 +224,7 @@ class MetadataFlagsTest(unittest.TestCase):
         #   main thread. So, it need another method to store the
         #   exceptions and raise them again in main thread.
         unhandled_exceptions = queue.Queue()
-        with listening_socket() as (host, port):
+        with bound_socket(listen=False) as (host, port):
             addr = '{}:{}'.format(host, port)
             wg = test_common.WaitGroup(len(_ALL_CALL_CASES))
 

src/python/grpcio_tests/tests/unit/framework/common/__init__.py

@@ -16,7 +16,7 @@ import contextlib
 import socket
 
 
-def get_socket(bind_address='localhost', sock_options=(socket.SO_REUSEPORT,)):
+def get_socket(bind_address='localhost', listen=True, sock_options=(socket.SO_REUSEPORT,)):
     """Opens a listening socket on an arbitrary port.
 
     Useful for reserving a port for a system-under-test.
@@ -38,7 +38,8 @@ def get_socket(bind_address='localhost', sock_options=(socket.SO_REUSEPORT,)):
             for sock_option in _sock_options:
                 sock.setsockopt(socket.SOL_SOCKET, sock_option, 1)
             sock.bind((bind_address, 0))
-            sock.listen(1)
+            if listen:
+                sock.listen(1)
             return bind_address, sock.getsockname()[1], sock
         except socket.error:
             continue
@@ -46,9 +47,10 @@ def get_socket(bind_address='localhost', sock_options=(socket.SO_REUSEPORT,)):
 
 
 @contextlib.contextmanager
-def listening_socket(bind_address='localhost', sock_options=(socket.SO_REUSEPORT,)):
+def bound_socket(bind_address='localhost', listen=True, sock_options=(socket.SO_REUSEPORT,)):
     # TODO: Docstring.
-    host, port, sock = get_socket(bind_address=bind_address, sock_options=sock_options)
+    # TODO: Just yield address?
+    host, port, sock = get_socket(bind_address=bind_address, listen=listen, sock_options=sock_options)
     try:
         yield host, port
     finally: