Merge pull request #13667 from mehrdada/servicercontext-abort

Introduce ServicerContext.abort for terminating RPCs with non-OK status

src/python/grpcio/grpc/__init__.py

@@ -834,28 +834,48 @@ class ServicerContext(six.with_metaclass(abc.ABCMeta, RpcContext)):
     """
         raise NotImplementedError()
 
+    @abc.abstractmethod
+    def abort(self, code, details):
+        """Raises an exception to terminate the RPC with a non-OK status.
+
+        The code and details passed as arguments will supercede any existing
+        ones.
+
+        Args:
+          code: A StatusCode object to be sent to the client.
+            It must not be StatusCode.OK.
+          details: An ASCII-encodable string to be sent to the client upon
+            termination of the RPC.
+
+        Raises:
+          Exception: An exception is always raised to signal the abortion the
+            RPC to the gRPC runtime.
+        """
+        raise NotImplementedError()
+
     @abc.abstractmethod
     def set_code(self, code):
         """Sets the value to be used as status code upon RPC completion.
 
-    This method need not be called by method implementations if they wish the
-    gRPC runtime to determine the status code of the RPC.
+        This method need not be called by method implementations if they wish
+        the gRPC runtime to determine the status code of the RPC.
 
-    Args:
-      code: A StatusCode object to be sent to the client.
-    """
+        Args:
+          code: A StatusCode object to be sent to the client.
+        """
         raise NotImplementedError()
 
     @abc.abstractmethod
     def set_details(self, details):
         """Sets the value to be used as detail string upon RPC completion.
 
-    This method need not be called by method implementations if they have no
-    details to transmit.
+        This method need not be called by method implementations if they have
+        no details to transmit.
 
-    Args:
-      details: An arbitrary string to be sent to the client upon completion.
-    """
+        Args:
+          details: An ASCII-encodable string to be sent to the client upon
+            termination of the RPC.
+        """
         raise NotImplementedError()
 
 

src/python/grpcio/grpc/_server.py

@@ -96,6 +96,7 @@ class _RPCState(object):
         self.statused = False
         self.rpc_errors = []
         self.callbacks = []
+        self.abortion = None
 
 
 def _raise_rpc_error(state):
@@ -273,6 +274,13 @@ class _Context(grpc.ServicerContext):
         with self._state.condition:
             self._state.trailing_metadata = trailing_metadata
 
+    def abort(self, code, details):
+        with self._state.condition:
+            self._state.code = code
+            self._state.details = _common.encode(details)
+            self._state.abortion = Exception()
+            raise self._state.abortion
+
     def set_code(self, code):
         with self._state.condition:
             self._state.code = code
@@ -369,7 +377,10 @@ def _call_behavior(rpc_event, state, behavior, argument, request_deserializer):
         return behavior(argument, context), True
     except Exception as exception:  # pylint: disable=broad-except
         with state.condition:
-            if exception not in state.rpc_errors:
+            if exception is state.abortion:
+                _abort(state, rpc_event.operation_call,
+                       cygrpc.StatusCode.unknown, b'RPC Aborted')
+            elif exception not in state.rpc_errors:
                 details = 'Exception calling application: {}'.format(exception)
                 logging.exception(details)
                 _abort(state, rpc_event.operation_call,
@@ -384,7 +395,10 @@ def _take_response_from_response_iterator(rpc_event, state, response_iterator):
         return None, True
     except Exception as exception:  # pylint: disable=broad-except
         with state.condition:
-            if exception not in state.rpc_errors:
+            if exception is state.abortion:
+                _abort(state, rpc_event.operation_call,
+                       cygrpc.StatusCode.unknown, b'RPC Aborted')
+            elif exception not in state.rpc_errors:
                 details = 'Exception iterating responses: {}'.format(exception)
                 logging.exception(details)
                 _abort(state, rpc_event.operation_call,
@@ -430,12 +444,11 @@ def _send_response(rpc_event, state, serialized_response):
 def _status(rpc_event, state, serialized_response):
     with state.condition:
         if state.client is not _CANCELLED:
-            trailing_metadata = state.trailing_metadata
             code = _completion_code(state)
             details = _details(state)
             operations = [
                 cygrpc.operation_send_status_from_server(
-                    trailing_metadata, code, details, _EMPTY_FLAGS),
+                    state.trailing_metadata, code, details, _EMPTY_FLAGS),
             ]
             if state.initial_metadata_allowed:
                 operations.append(

src/python/grpcio_testing/grpc_testing/_server/_servicer_context.py

@@ -67,6 +67,9 @@ class ServicerContext(grpc.ServicerContext):
         self._rpc.set_trailing_metadata(
             _common.fuss_with_metadata(trailing_metadata))
 
+    def abort(self, code, details):
+        raise NotImplementedError()
+
     def set_code(self, code):
         self._rpc.set_code(code)
 

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

@@ -56,6 +56,7 @@ class _Servicer(object):
 
     def __init__(self):
         self._lock = threading.Lock()
+        self._abort_call = False
         self._code = None
         self._details = None
         self._exception = False
@@ -67,10 +68,13 @@ class _Servicer(object):
             self._received_client_metadata = context.invocation_metadata()
             context.send_initial_metadata(_SERVER_INITIAL_METADATA)
             context.set_trailing_metadata(_SERVER_TRAILING_METADATA)
-            if self._code is not None:
-                context.set_code(self._code)
-            if self._details is not None:
-                context.set_details(self._details)
+            if self._abort_call:
+                context.abort(self._code, self._details)
+            else:
+                if self._code is not None:
+                    context.set_code(self._code)
+                if self._details is not None:
+                    context.set_details(self._details)
             if self._exception:
                 raise test_control.Defect()
             else:
@@ -81,10 +85,13 @@ class _Servicer(object):
             self._received_client_metadata = context.invocation_metadata()
             context.send_initial_metadata(_SERVER_INITIAL_METADATA)
             context.set_trailing_metadata(_SERVER_TRAILING_METADATA)
-            if self._code is not None:
-                context.set_code(self._code)
-            if self._details is not None:
-                context.set_details(self._details)
+            if self._abort_call:
+                context.abort(self._code, self._details)
+            else:
+                if self._code is not None:
+                    context.set_code(self._code)
+                if self._details is not None:
+                    context.set_details(self._details)
             for _ in range(test_constants.STREAM_LENGTH // 2):
                 yield _SERIALIZED_RESPONSE
             if self._exception:
@@ -95,14 +102,16 @@ class _Servicer(object):
             self._received_client_metadata = context.invocation_metadata()
             context.send_initial_metadata(_SERVER_INITIAL_METADATA)
             context.set_trailing_metadata(_SERVER_TRAILING_METADATA)
-            if self._code is not None:
-                context.set_code(self._code)
-            if self._details is not None:
-                context.set_details(self._details)
             # TODO(https://github.com/grpc/grpc/issues/6891): just ignore the
             # request iterator.
-            for ignored_request in request_iterator:
-                pass
+            list(request_iterator)
+            if self._abort_call:
+                context.abort(self._code, self._details)
+            else:
+                if self._code is not None:
+                    context.set_code(self._code)
+                if self._details is not None:
+                    context.set_details(self._details)
             if self._exception:
                 raise test_control.Defect()
             else:
@@ -113,19 +122,25 @@ class _Servicer(object):
             self._received_client_metadata = context.invocation_metadata()
             context.send_initial_metadata(_SERVER_INITIAL_METADATA)
             context.set_trailing_metadata(_SERVER_TRAILING_METADATA)
-            if self._code is not None:
-                context.set_code(self._code)
-            if self._details is not None:
-                context.set_details(self._details)
             # TODO(https://github.com/grpc/grpc/issues/6891): just ignore the
             # request iterator.
-            for ignored_request in request_iterator:
-                pass
+            list(request_iterator)
+            if self._abort_call:
+                context.abort(self._code, self._details)
+            else:
+                if self._code is not None:
+                    context.set_code(self._code)
+                if self._details is not None:
+                    context.set_details(self._details)
             for _ in range(test_constants.STREAM_LENGTH // 3):
                 yield object()
             if self._exception:
                 raise test_control.Defect()
 
+    def set_abort_call(self):
+        with self._lock:
+            self._abort_call = True
+
     def set_code(self, code):
         with self._lock:
             self._code = code
@@ -212,11 +227,10 @@ class MetadataCodeDetailsTest(unittest.TestCase):
     def testSuccessfulUnaryStream(self):
         self._servicer.set_details(_DETAILS)
 
-        call = self._unary_stream(
+        response_iterator_call = self._unary_stream(
             _SERIALIZED_REQUEST, metadata=_CLIENT_METADATA)
-        received_initial_metadata = call.initial_metadata()
-        for _ in call:
-            pass
+        received_initial_metadata = response_iterator_call.initial_metadata()
+        list(response_iterator_call)
 
         self.assertTrue(
             test_common.metadata_transmitted(
@@ -225,10 +239,11 @@ class MetadataCodeDetailsTest(unittest.TestCase):
             test_common.metadata_transmitted(_SERVER_INITIAL_METADATA,
                                              received_initial_metadata))
         self.assertTrue(
-            test_common.metadata_transmitted(_SERVER_TRAILING_METADATA,
-                                             call.trailing_metadata()))
-        self.assertIs(grpc.StatusCode.OK, call.code())
-        self.assertEqual(_DETAILS, call.details())
+            test_common.metadata_transmitted(
+                _SERVER_TRAILING_METADATA,
+                response_iterator_call.trailing_metadata()))
+        self.assertIs(grpc.StatusCode.OK, response_iterator_call.code())
+        self.assertEqual(_DETAILS, response_iterator_call.details())
 
     def testSuccessfulStreamUnary(self):
         self._servicer.set_details(_DETAILS)
@@ -252,12 +267,11 @@ class MetadataCodeDetailsTest(unittest.TestCase):
     def testSuccessfulStreamStream(self):
         self._servicer.set_details(_DETAILS)
 
-        call = self._stream_stream(
+        response_iterator_call = self._stream_stream(
             iter([object()] * test_constants.STREAM_LENGTH),
             metadata=_CLIENT_METADATA)
-        received_initial_metadata = call.initial_metadata()
-        for _ in call:
-            pass
+        received_initial_metadata = response_iterator_call.initial_metadata()
+        list(response_iterator_call)
 
         self.assertTrue(
             test_common.metadata_transmitted(
@@ -266,10 +280,106 @@ class MetadataCodeDetailsTest(unittest.TestCase):
             test_common.metadata_transmitted(_SERVER_INITIAL_METADATA,
                                              received_initial_metadata))
         self.assertTrue(
-            test_common.metadata_transmitted(_SERVER_TRAILING_METADATA,
-                                             call.trailing_metadata()))
-        self.assertIs(grpc.StatusCode.OK, call.code())
-        self.assertEqual(_DETAILS, call.details())
+            test_common.metadata_transmitted(
+                _SERVER_TRAILING_METADATA,
+                response_iterator_call.trailing_metadata()))
+        self.assertIs(grpc.StatusCode.OK, response_iterator_call.code())
+        self.assertEqual(_DETAILS, response_iterator_call.details())
+
+    def testAbortedUnaryUnary(self):
+        self._servicer.set_code(_NON_OK_CODE)
+        self._servicer.set_details(_DETAILS)
+        self._servicer.set_abort_call()
+
+        with self.assertRaises(grpc.RpcError) as exception_context:
+            self._unary_unary.with_call(object(), metadata=_CLIENT_METADATA)
+
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _CLIENT_METADATA, self._servicer.received_client_metadata()))
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _SERVER_INITIAL_METADATA,
+                exception_context.exception.initial_metadata()))
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _SERVER_TRAILING_METADATA,
+                exception_context.exception.trailing_metadata()))
+        self.assertIs(_NON_OK_CODE, exception_context.exception.code())
+        self.assertEqual(_DETAILS, exception_context.exception.details())
+
+    def testAbortedUnaryStream(self):
+        self._servicer.set_code(_NON_OK_CODE)
+        self._servicer.set_details(_DETAILS)
+        self._servicer.set_abort_call()
+
+        response_iterator_call = self._unary_stream(
+            _SERIALIZED_REQUEST, metadata=_CLIENT_METADATA)
+        received_initial_metadata = response_iterator_call.initial_metadata()
+        with self.assertRaises(grpc.RpcError):
+            self.assertEqual(len(list(response_iterator_call)), 0)
+
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _CLIENT_METADATA, self._servicer.received_client_metadata()))
+        self.assertTrue(
+            test_common.metadata_transmitted(_SERVER_INITIAL_METADATA,
+                                             received_initial_metadata))
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _SERVER_TRAILING_METADATA,
+                response_iterator_call.trailing_metadata()))
+        self.assertIs(_NON_OK_CODE, response_iterator_call.code())
+        self.assertEqual(_DETAILS, response_iterator_call.details())
+
+    def testAbortedStreamUnary(self):
+        self._servicer.set_code(_NON_OK_CODE)
+        self._servicer.set_details(_DETAILS)
+        self._servicer.set_abort_call()
+
+        with self.assertRaises(grpc.RpcError) as exception_context:
+            self._stream_unary.with_call(
+                iter([_SERIALIZED_REQUEST] * test_constants.STREAM_LENGTH),
+                metadata=_CLIENT_METADATA)
+
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _CLIENT_METADATA, self._servicer.received_client_metadata()))
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _SERVER_INITIAL_METADATA,
+                exception_context.exception.initial_metadata()))
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _SERVER_TRAILING_METADATA,
+                exception_context.exception.trailing_metadata()))
+        self.assertIs(_NON_OK_CODE, exception_context.exception.code())
+        self.assertEqual(_DETAILS, exception_context.exception.details())
+
+    def testAbortedStreamStream(self):
+        self._servicer.set_code(_NON_OK_CODE)
+        self._servicer.set_details(_DETAILS)
+        self._servicer.set_abort_call()
+
+        response_iterator_call = self._stream_stream(
+            iter([object()] * test_constants.STREAM_LENGTH),
+            metadata=_CLIENT_METADATA)
+        received_initial_metadata = response_iterator_call.initial_metadata()
+        with self.assertRaises(grpc.RpcError):
+            self.assertEqual(len(list(response_iterator_call)), 0)
+
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _CLIENT_METADATA, self._servicer.received_client_metadata()))
+        self.assertTrue(
+            test_common.metadata_transmitted(_SERVER_INITIAL_METADATA,
+                                             received_initial_metadata))
+        self.assertTrue(
+            test_common.metadata_transmitted(
+                _SERVER_TRAILING_METADATA,
+                response_iterator_call.trailing_metadata()))
+        self.assertIs(_NON_OK_CODE, response_iterator_call.code())
+        self.assertEqual(_DETAILS, response_iterator_call.details())
 
     def testCustomCodeUnaryUnary(self):
         self._servicer.set_code(_NON_OK_CODE)
@@ -296,12 +406,11 @@ class MetadataCodeDetailsTest(unittest.TestCase):
         self._servicer.set_code(_NON_OK_CODE)
         self._servicer.set_details(_DETAILS)
 
-        call = self._unary_stream(
+        response_iterator_call = self._unary_stream(
             _SERIALIZED_REQUEST, metadata=_CLIENT_METADATA)
-        received_initial_metadata = call.initial_metadata()
+        received_initial_metadata = response_iterator_call.initial_metadata()
         with self.assertRaises(grpc.RpcError):
-            for _ in call:
-                pass
+            list(response_iterator_call)
 
         self.assertTrue(
             test_common.metadata_transmitted(
@@ -310,10 +419,11 @@ class MetadataCodeDetailsTest(unittest.TestCase):
             test_common.metadata_transmitted(_SERVER_INITIAL_METADATA,
                                              received_initial_metadata))
         self.assertTrue(
-            test_common.metadata_transmitted(_SERVER_TRAILING_METADATA,
-                                             call.trailing_metadata()))
-        self.assertIs(_NON_OK_CODE, call.code())
-        self.assertEqual(_DETAILS, call.details())
+            test_common.metadata_transmitted(
+                _SERVER_TRAILING_METADATA,
+                response_iterator_call.trailing_metadata()))
+        self.assertIs(_NON_OK_CODE, response_iterator_call.code())
+        self.assertEqual(_DETAILS, response_iterator_call.details())
 
     def testCustomCodeStreamUnary(self):
         self._servicer.set_code(_NON_OK_CODE)
@@ -342,13 +452,12 @@ class MetadataCodeDetailsTest(unittest.TestCase):
         self._servicer.set_code(_NON_OK_CODE)
         self._servicer.set_details(_DETAILS)
 
-        call = self._stream_stream(
+        response_iterator_call = self._stream_stream(
             iter([object()] * test_constants.STREAM_LENGTH),
             metadata=_CLIENT_METADATA)
-        received_initial_metadata = call.initial_metadata()
+        received_initial_metadata = response_iterator_call.initial_metadata()
         with self.assertRaises(grpc.RpcError) as exception_context:
-            for _ in call:
-                pass
+            list(response_iterator_call)
 
         self.assertTrue(
             test_common.metadata_transmitted(
@@ -390,12 +499,11 @@ class MetadataCodeDetailsTest(unittest.TestCase):
         self._servicer.set_details(_DETAILS)
         self._servicer.set_exception()
 
-        call = self._unary_stream(
+        response_iterator_call = self._unary_stream(
             _SERIALIZED_REQUEST, metadata=_CLIENT_METADATA)
-        received_initial_metadata = call.initial_metadata()
+        received_initial_metadata = response_iterator_call.initial_metadata()
         with self.assertRaises(grpc.RpcError):
-            for _ in call:
-                pass
+            list(response_iterator_call)
 
         self.assertTrue(
             test_common.metadata_transmitted(
@@ -404,10 +512,11 @@ class MetadataCodeDetailsTest(unittest.TestCase):
             test_common.metadata_transmitted(_SERVER_INITIAL_METADATA,
                                              received_initial_metadata))
         self.assertTrue(
-            test_common.metadata_transmitted(_SERVER_TRAILING_METADATA,
-                                             call.trailing_metadata()))
-        self.assertIs(_NON_OK_CODE, call.code())
-        self.assertEqual(_DETAILS, call.details())
+            test_common.metadata_transmitted(
+                _SERVER_TRAILING_METADATA,
+                response_iterator_call.trailing_metadata()))
+        self.assertIs(_NON_OK_CODE, response_iterator_call.code())
+        self.assertEqual(_DETAILS, response_iterator_call.details())
 
     def testCustomCodeExceptionStreamUnary(self):
         self._servicer.set_code(_NON_OK_CODE)
@@ -438,13 +547,12 @@ class MetadataCodeDetailsTest(unittest.TestCase):
         self._servicer.set_details(_DETAILS)
         self._servicer.set_exception()
 
-        call = self._stream_stream(
+        response_iterator_call = self._stream_stream(
             iter([object()] * test_constants.STREAM_LENGTH),
             metadata=_CLIENT_METADATA)
-        received_initial_metadata = call.initial_metadata()
+        received_initial_metadata = response_iterator_call.initial_metadata()
         with self.assertRaises(grpc.RpcError):
-            for _ in call:
-                pass
+            list(response_iterator_call)
 
         self.assertTrue(
             test_common.metadata_transmitted(
@@ -453,10 +561,11 @@ class MetadataCodeDetailsTest(unittest.TestCase):
             test_common.metadata_transmitted(_SERVER_INITIAL_METADATA,
                                              received_initial_metadata))
         self.assertTrue(
-            test_common.metadata_transmitted(_SERVER_TRAILING_METADATA,
-                                             call.trailing_metadata()))
-        self.assertIs(_NON_OK_CODE, call.code())
-        self.assertEqual(_DETAILS, call.details())
+            test_common.metadata_transmitted(
+                _SERVER_TRAILING_METADATA,
+                response_iterator_call.trailing_metadata()))
+        self.assertIs(_NON_OK_CODE, response_iterator_call.code())
+        self.assertEqual(_DETAILS, response_iterator_call.details())
 
     def testCustomCodeReturnNoneUnaryUnary(self):
         self._servicer.set_code(_NON_OK_CODE)