Supply the event loop to aio iomgr in test case level

src/python/grpcio_tests/commands.py

@@ -119,8 +119,6 @@ class TestAio(setuptools.Command):
         pass
 
     def run(self):
-        from grpc.experimental import aio
-        aio.init_grpc_aio()
         self._add_eggs_to_path()
 
         import tests

src/python/grpcio_tests/tests_aio/unit/BUILD.bazel

@@ -20,6 +20,12 @@ package(
 GRPC_ASYNC_TESTS = glob(["*_test.py"])
 
 
+py_library(
+    name = "_test_base",
+    srcs_version = "PY3",
+    srcs = ["_test_base.py"],
+)
+
 py_library(
     name = "_test_server",
     srcs_version = "PY3",
@@ -41,6 +47,7 @@ py_library(
         python_version="PY3",
         deps=[
             ":_test_server",
+            ":_test_base",
             "//src/python/grpcio/grpc:grpcio",
             "//src/proto/grpc/testing:py_messages_proto",
             "//src/proto/grpc/testing:benchmark_service_py_pb2_grpc",

src/python/grpcio_tests/tests_aio/unit/channel_test.py

@@ -22,9 +22,10 @@ from grpc.experimental import aio
 from src.proto.grpc.testing import messages_pb2
 from tests.unit.framework.common import test_constants
 from tests_aio.unit._test_server import start_test_server
+from tests_aio.unit._test_base import AioTestBase
 
 
-class TestChannel(unittest.TestCase):
+class TestChannel(AioTestBase):
 
     def test_async_context(self):
 
@@ -40,7 +41,7 @@ class TestChannel(unittest.TestCase):
                 )
                 await hi(messages_pb2.SimpleRequest())
 
-        asyncio.get_event_loop().run_until_complete(coro())
+        self._loop.run_until_complete(coro())
 
     def test_unary_unary(self):
 
@@ -58,7 +59,7 @@ class TestChannel(unittest.TestCase):
 
             await channel.close()
 
-        asyncio.get_event_loop().run_until_complete(coro())
+        self._loop.run_until_complete(coro())
 
     def test_unary_call_times_out(self):
 
@@ -90,7 +91,7 @@ class TestChannel(unittest.TestCase):
                 self.assertIsNotNone(
                     exception_context.exception.trailing_metadata())
 
-        asyncio.get_event_loop().run_until_complete(coro())
+        self._loop.run_until_complete(coro())
 
 
 if __name__ == '__main__':