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Diffstat (limited to 'src/python/grpcio/grpc/_channel.py')
| -rw-r--r-- | src/python/grpcio/grpc/_channel.py | 904 |
1 files changed, 904 insertions, 0 deletions
diff --git a/src/python/grpcio/grpc/_channel.py b/src/python/grpcio/grpc/_channel.py new file mode 100644 index 0000000000..a89b501303 --- /dev/null +++ b/src/python/grpcio/grpc/_channel.py @@ -0,0 +1,904 @@ +# Copyright 2016, Google Inc. +# All rights reserved. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above +# copyright notice, this list of conditions and the following disclaimer +# in the documentation and/or other materials provided with the +# distribution. +# * Neither the name of Google Inc. nor the names of its +# contributors may be used to endorse or promote products derived from +# this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +"""Invocation-side implementation of gRPC Python.""" + +import sys +import threading +import time + +import grpc +from grpc import _common +from grpc import _grpcio_metadata +from grpc.framework.foundation import callable_util +from grpc._cython import cygrpc + +_USER_AGENT = 'Python-gRPC-{}'.format(_grpcio_metadata.__version__) + +_EMPTY_FLAGS = 0 +_INFINITE_FUTURE = cygrpc.Timespec(float('+inf')) +_EMPTY_METADATA = cygrpc.Metadata(()) + +_UNARY_UNARY_INITIAL_DUE = ( + cygrpc.OperationType.send_initial_metadata, + cygrpc.OperationType.send_message, + cygrpc.OperationType.send_close_from_client, + cygrpc.OperationType.receive_initial_metadata, + cygrpc.OperationType.receive_message, + cygrpc.OperationType.receive_status_on_client, +) +_UNARY_STREAM_INITIAL_DUE = ( + cygrpc.OperationType.send_initial_metadata, + cygrpc.OperationType.send_message, + cygrpc.OperationType.send_close_from_client, + cygrpc.OperationType.receive_initial_metadata, + cygrpc.OperationType.receive_status_on_client, +) +_STREAM_UNARY_INITIAL_DUE = ( + cygrpc.OperationType.send_initial_metadata, + cygrpc.OperationType.receive_initial_metadata, + cygrpc.OperationType.receive_message, + cygrpc.OperationType.receive_status_on_client, +) +_STREAM_STREAM_INITIAL_DUE = ( + cygrpc.OperationType.send_initial_metadata, + cygrpc.OperationType.receive_initial_metadata, + cygrpc.OperationType.receive_status_on_client, +) + +_CHANNEL_SUBSCRIPTION_CALLBACK_ERROR_LOG_MESSAGE = ( + 'Exception calling channel subscription callback!') + + +def _deadline(timeout): + if timeout is None: + return None, _INFINITE_FUTURE + else: + deadline = time.time() + timeout + return deadline, cygrpc.Timespec(deadline) + + +def _unknown_code_details(unknown_cygrpc_code, details): + return 'Server sent unknown code {} and details "{}"'.format( + unknown_cygrpc_code, details) + + +def _wait_once_until(condition, until): + if until is None: + condition.wait() + else: + remaining = until - time.time() + if remaining < 0: + raise grpc.FutureTimeoutError() + else: + condition.wait(timeout=remaining) + + +class _RPCState(object): + + def __init__(self, due, initial_metadata, trailing_metadata, code, details): + self.condition = threading.Condition() + # The cygrpc.OperationType objects representing events due from the RPC's + # completion queue. + self.due = set(due) + self.initial_metadata = initial_metadata + self.response = None + self.trailing_metadata = trailing_metadata + self.code = code + self.details = details + # The semantics of grpc.Future.cancel and grpc.Future.cancelled are + # slightly wonky, so they have to be tracked separately from the rest of the + # result of the RPC. This field tracks whether cancellation was requested + # prior to termination of the RPC. + self.cancelled = False + self.callbacks = [] + + +def _abort(state, code, details): + if state.code is None: + state.code = code + state.details = details + if state.initial_metadata is None: + state.initial_metadata = _EMPTY_METADATA + state.trailing_metadata = _EMPTY_METADATA + + +def _handle_event(event, state, response_deserializer): + callbacks = [] + for batch_operation in event.batch_operations: + operation_type = batch_operation.type + state.due.remove(operation_type) + if operation_type == cygrpc.OperationType.receive_initial_metadata: + state.initial_metadata = batch_operation.received_metadata + elif operation_type == cygrpc.OperationType.receive_message: + serialized_response = batch_operation.received_message.bytes() + if serialized_response is not None: + response = _common.deserialize( + serialized_response, response_deserializer) + if response is None: + details = 'Exception deserializing response!' + _abort(state, grpc.StatusCode.INTERNAL, details) + else: + state.response = response + elif operation_type == cygrpc.OperationType.receive_status_on_client: + state.trailing_metadata = batch_operation.received_metadata + if state.code is None: + code = _common.CYGRPC_STATUS_CODE_TO_STATUS_CODE.get( + batch_operation.received_status_code) + if code is None: + state.code = grpc.StatusCode.UNKNOWN + state.details = _unknown_code_details( + batch_operation.received_status_code, + batch_operation.received_status_details) + else: + state.code = code + state.details = batch_operation.received_status_details + callbacks.extend(state.callbacks) + state.callbacks = None + return callbacks + + +def _event_handler(state, call, response_deserializer): + def handle_event(event): + with state.condition: + callbacks = _handle_event(event, state, response_deserializer) + state.condition.notify_all() + done = not state.due + for callback in callbacks: + callback() + return call if done else None + return handle_event + + +def _consume_request_iterator( + request_iterator, state, call, request_serializer): + event_handler = _event_handler(state, call, None) + + def consume_request_iterator(): + for request in request_iterator: + serialized_request = _common.serialize(request, request_serializer) + with state.condition: + if state.code is None and not state.cancelled: + if serialized_request is None: + call.cancel() + details = 'Exception serializing request!' + _abort(state, grpc.StatusCode.INTERNAL, details) + return + else: + operations = ( + cygrpc.operation_send_message( + serialized_request, _EMPTY_FLAGS), + ) + call.start_batch(cygrpc.Operations(operations), event_handler) + state.due.add(cygrpc.OperationType.send_message) + while True: + state.condition.wait() + if state.code is None: + if cygrpc.OperationType.send_message not in state.due: + break + else: + return + else: + return + with state.condition: + if state.code is None: + operations = ( + cygrpc.operation_send_close_from_client(_EMPTY_FLAGS), + ) + call.start_batch(cygrpc.Operations(operations), event_handler) + state.due.add(cygrpc.OperationType.send_close_from_client) + + def stop_consumption_thread(timeout): + with state.condition: + if state.code is None: + call.cancel() + state.cancelled = True + _abort(state, grpc.StatusCode.CANCELLED, 'Cancelled!') + state.condition.notify_all() + + consumption_thread = _common.CleanupThread( + stop_consumption_thread, target=consume_request_iterator) + consumption_thread.start() + + +class _Rendezvous(grpc.RpcError, grpc.Future, grpc.Call): + + def __init__(self, state, call, response_deserializer, deadline): + super(_Rendezvous, self).__init__() + self._state = state + self._call = call + self._response_deserializer = response_deserializer + self._deadline = deadline + + def cancel(self): + with self._state.condition: + if self._state.code is None: + self._call.cancel() + self._state.cancelled = True + _abort(self._state, grpc.StatusCode.CANCELLED, 'Cancelled!') + self._state.condition.notify_all() + return False + + def cancelled(self): + with self._state.condition: + return self._state.cancelled + + def running(self): + with self._state.condition: + return self._state.code is None + + def done(self): + with self._state.condition: + return self._state.code is not None + + def result(self, timeout=None): + until = None if timeout is None else time.time() + timeout + with self._state.condition: + while True: + if self._state.code is None: + _wait_once_until(self._state.condition, until) + elif self._state.code is grpc.StatusCode.OK: + return self._state.response + elif self._state.cancelled: + raise grpc.FutureCancelledError() + else: + raise self + + def exception(self, timeout=None): + until = None if timeout is None else time.time() + timeout + with self._state.condition: + while True: + if self._state.code is None: + _wait_once_until(self._state.condition, until) + elif self._state.code is grpc.StatusCode.OK: + return None + elif self._state.cancelled: + raise grpc.FutureCancelledError() + else: + return self + + def traceback(self, timeout=None): + until = None if timeout is None else time.time() + timeout + with self._state.condition: + while True: + if self._state.code is None: + _wait_once_until(self._state.condition, until) + elif self._state.code is grpc.StatusCode.OK: + return None + elif self._state.cancelled: + raise grpc.FutureCancelledError() + else: + try: + raise self + except grpc.RpcError: + return sys.exc_info()[2] + + def add_done_callback(self, fn): + with self._state.condition: + if self._state.code is None: + self._state.callbacks.append(lambda: fn(self)) + return + + fn(self) + + def _next(self): + with self._state.condition: + if self._state.code is None: + event_handler = _event_handler( + self._state, self._call, self._response_deserializer) + self._call.start_batch( + cygrpc.Operations( + (cygrpc.operation_receive_message(_EMPTY_FLAGS),)), + event_handler) + self._state.due.add(cygrpc.OperationType.receive_message) + elif self._state.code is grpc.StatusCode.OK: + raise StopIteration() + else: + raise self + while True: + self._state.condition.wait() + if self._state.response is not None: + response = self._state.response + self._state.response = None + return response + elif cygrpc.OperationType.receive_message not in self._state.due: + if self._state.code is grpc.StatusCode.OK: + raise StopIteration() + elif self._state.code is not None: + raise self + + def __iter__(self): + return self + + def __next__(self): + return self._next() + + def next(self): + return self._next() + + def is_active(self): + with self._state.condition: + return self._state.code is None + + def time_remaining(self): + if self._deadline is None: + return None + else: + return max(self._deadline - time.time(), 0) + + def add_cancellation_callback(self, callback): + with self._state.condition: + if self._state.callbacks is None: + return False + else: + self._state.callbacks.append(lambda unused_future: callback()) + return True + + def initial_metadata(self): + with self._state.condition: + while self._state.initial_metadata is None: + self._state.condition.wait() + return _common.application_metadata(self._state.initial_metadata) + + def trailing_metadata(self): + with self._state.condition: + while self._state.trailing_metadata is None: + self._state.condition.wait() + return _common.application_metadata(self._state.trailing_metadata) + + def code(self): + with self._state.condition: + while self._state.code is None: + self._state.condition.wait() + return self._state.code + + def details(self): + with self._state.condition: + while self._state.details is None: + self._state.condition.wait() + return _common.decode(self._state.details) + + def _repr(self): + with self._state.condition: + if self._state.code is None: + return '<_Rendezvous object of in-flight RPC>' + else: + return '<_Rendezvous of RPC that terminated with ({}, {})>'.format( + self._state.code, _common.decode(self._state.details)) + + def __repr__(self): + return self._repr() + + def __str__(self): + return self._repr() + + def __del__(self): + with self._state.condition: + if self._state.code is None: + self._call.cancel() + self._state.cancelled = True + self._state.code = grpc.StatusCode.CANCELLED + self._state.condition.notify_all() + + +def _start_unary_request(request, timeout, request_serializer): + deadline, deadline_timespec = _deadline(timeout) + serialized_request = _common.serialize(request, request_serializer) + if serialized_request is None: + state = _RPCState( + (), _EMPTY_METADATA, _EMPTY_METADATA, grpc.StatusCode.INTERNAL, + 'Exception serializing request!') + rendezvous = _Rendezvous(state, None, None, deadline) + return deadline, deadline_timespec, None, rendezvous + else: + return deadline, deadline_timespec, serialized_request, None + + +def _end_unary_response_blocking(state, with_call, deadline): + if state.code is grpc.StatusCode.OK: + if with_call: + rendezvous = _Rendezvous(state, None, None, deadline) + return state.response, rendezvous + else: + return state.response + else: + raise _Rendezvous(state, None, None, deadline) + + +class _UnaryUnaryMultiCallable(grpc.UnaryUnaryMultiCallable): + + def __init__( + self, channel, create_managed_call, method, request_serializer, + response_deserializer): + self._channel = channel + self._create_managed_call = create_managed_call + self._method = method + self._request_serializer = request_serializer + self._response_deserializer = response_deserializer + + def _prepare(self, request, timeout, metadata): + deadline, deadline_timespec, serialized_request, rendezvous = ( + _start_unary_request(request, timeout, self._request_serializer)) + if serialized_request is None: + return None, None, None, None, rendezvous + else: + state = _RPCState(_UNARY_UNARY_INITIAL_DUE, None, None, None, None) + operations = ( + cygrpc.operation_send_initial_metadata( + _common.cygrpc_metadata(metadata), _EMPTY_FLAGS), + cygrpc.operation_send_message(serialized_request, _EMPTY_FLAGS), + cygrpc.operation_send_close_from_client(_EMPTY_FLAGS), + cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS), + cygrpc.operation_receive_message(_EMPTY_FLAGS), + cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS), + ) + return state, operations, deadline, deadline_timespec, None + + def _blocking(self, request, timeout, metadata, credentials): + state, operations, deadline, deadline_timespec, rendezvous = self._prepare( + request, timeout, metadata) + if rendezvous: + raise rendezvous + else: + completion_queue = cygrpc.CompletionQueue() + call = self._channel.create_call( + None, 0, completion_queue, self._method, None, deadline_timespec) + if credentials is not None: + call.set_credentials(credentials._credentials) + call.start_batch(cygrpc.Operations(operations), None) + _handle_event(completion_queue.poll(), state, self._response_deserializer) + return state, deadline + + def __call__(self, request, timeout=None, metadata=None, credentials=None): + state, deadline, = self._blocking(request, timeout, metadata, credentials) + return _end_unary_response_blocking(state, False, deadline) + + def with_call(self, request, timeout=None, metadata=None, credentials=None): + state, deadline, = self._blocking(request, timeout, metadata, credentials) + return _end_unary_response_blocking(state, True, deadline) + + def future(self, request, timeout=None, metadata=None, credentials=None): + state, operations, deadline, deadline_timespec, rendezvous = self._prepare( + request, timeout, metadata) + if rendezvous: + return rendezvous + else: + call = self._create_managed_call( + None, 0, self._method, None, deadline_timespec) + if credentials is not None: + call.set_credentials(credentials._credentials) + event_handler = _event_handler(state, call, self._response_deserializer) + with state.condition: + call.start_batch(cygrpc.Operations(operations), event_handler) + return _Rendezvous(state, call, self._response_deserializer, deadline) + + +class _UnaryStreamMultiCallable(grpc.UnaryStreamMultiCallable): + + def __init__( + self, channel, create_managed_call, method, request_serializer, + response_deserializer): + self._channel = channel + self._create_managed_call = create_managed_call + self._method = method + self._request_serializer = request_serializer + self._response_deserializer = response_deserializer + + def __call__(self, request, timeout=None, metadata=None, credentials=None): + deadline, deadline_timespec, serialized_request, rendezvous = ( + _start_unary_request(request, timeout, self._request_serializer)) + if serialized_request is None: + raise rendezvous + else: + state = _RPCState(_UNARY_STREAM_INITIAL_DUE, None, None, None, None) + call = self._create_managed_call( + None, 0, self._method, None, deadline_timespec) + if credentials is not None: + call.set_credentials(credentials._credentials) + event_handler = _event_handler(state, call, self._response_deserializer) + with state.condition: + call.start_batch( + cygrpc.Operations( + (cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),)), + event_handler) + operations = ( + cygrpc.operation_send_initial_metadata( + _common.cygrpc_metadata(metadata), _EMPTY_FLAGS), + cygrpc.operation_send_message(serialized_request, _EMPTY_FLAGS), + cygrpc.operation_send_close_from_client(_EMPTY_FLAGS), + cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS), + ) + call.start_batch(cygrpc.Operations(operations), event_handler) + return _Rendezvous(state, call, self._response_deserializer, deadline) + + +class _StreamUnaryMultiCallable(grpc.StreamUnaryMultiCallable): + + def __init__( + self, channel, create_managed_call, method, request_serializer, + response_deserializer): + self._channel = channel + self._create_managed_call = create_managed_call + self._method = method + self._request_serializer = request_serializer + self._response_deserializer = response_deserializer + + def _blocking(self, request_iterator, timeout, metadata, credentials): + deadline, deadline_timespec = _deadline(timeout) + state = _RPCState(_STREAM_UNARY_INITIAL_DUE, None, None, None, None) + completion_queue = cygrpc.CompletionQueue() + call = self._channel.create_call( + None, 0, completion_queue, self._method, None, deadline_timespec) + if credentials is not None: + call.set_credentials(credentials._credentials) + with state.condition: + call.start_batch( + cygrpc.Operations( + (cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),)), + None) + operations = ( + cygrpc.operation_send_initial_metadata( + _common.cygrpc_metadata(metadata), _EMPTY_FLAGS), + cygrpc.operation_receive_message(_EMPTY_FLAGS), + cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS), + ) + call.start_batch(cygrpc.Operations(operations), None) + _consume_request_iterator( + request_iterator, state, call, self._request_serializer) + while True: + event = completion_queue.poll() + with state.condition: + _handle_event(event, state, self._response_deserializer) + state.condition.notify_all() + if not state.due: + break + return state, deadline + + def __call__( + self, request_iterator, timeout=None, metadata=None, credentials=None): + state, deadline, = self._blocking( + request_iterator, timeout, metadata, credentials) + return _end_unary_response_blocking(state, False, deadline) + + def with_call( + self, request_iterator, timeout=None, metadata=None, credentials=None): + state, deadline, = self._blocking( + request_iterator, timeout, metadata, credentials) + return _end_unary_response_blocking(state, True, deadline) + + def future( + self, request_iterator, timeout=None, metadata=None, credentials=None): + deadline, deadline_timespec = _deadline(timeout) + state = _RPCState(_STREAM_UNARY_INITIAL_DUE, None, None, None, None) + call = self._create_managed_call( + None, 0, self._method, None, deadline_timespec) + if credentials is not None: + call.set_credentials(credentials._credentials) + event_handler = _event_handler(state, call, self._response_deserializer) + with state.condition: + call.start_batch( + cygrpc.Operations( + (cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),)), + event_handler) + operations = ( + cygrpc.operation_send_initial_metadata( + _common.cygrpc_metadata(metadata), _EMPTY_FLAGS), + cygrpc.operation_receive_message(_EMPTY_FLAGS), + cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS), + ) + call.start_batch(cygrpc.Operations(operations), event_handler) + _consume_request_iterator( + request_iterator, state, call, self._request_serializer) + return _Rendezvous(state, call, self._response_deserializer, deadline) + + +class _StreamStreamMultiCallable(grpc.StreamStreamMultiCallable): + + def __init__( + self, channel, create_managed_call, method, request_serializer, + response_deserializer): + self._channel = channel + self._create_managed_call = create_managed_call + self._method = method + self._request_serializer = request_serializer + self._response_deserializer = response_deserializer + + def __call__( + self, request_iterator, timeout=None, metadata=None, credentials=None): + deadline, deadline_timespec = _deadline(timeout) + state = _RPCState(_STREAM_STREAM_INITIAL_DUE, None, None, None, None) + call = self._create_managed_call( + None, 0, self._method, None, deadline_timespec) + if credentials is not None: + call.set_credentials(credentials._credentials) + event_handler = _event_handler(state, call, self._response_deserializer) + with state.condition: + call.start_batch( + cygrpc.Operations( + (cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),)), + event_handler) + operations = ( + cygrpc.operation_send_initial_metadata( + _common.cygrpc_metadata(metadata), _EMPTY_FLAGS), + cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS), + ) + call.start_batch(cygrpc.Operations(operations), event_handler) + _consume_request_iterator( + request_iterator, state, call, self._request_serializer) + return _Rendezvous(state, call, self._response_deserializer, deadline) + + +class _ChannelCallState(object): + + def __init__(self, channel): + self.lock = threading.Lock() + self.channel = channel + self.completion_queue = cygrpc.CompletionQueue() + self.managed_calls = None + + +def _run_channel_spin_thread(state): + def channel_spin(): + while True: + event = state.completion_queue.poll() + completed_call = event.tag(event) + if completed_call is not None: + with state.lock: + state.managed_calls.remove(completed_call) + if not state.managed_calls: + state.managed_calls = None + return + + def stop_channel_spin(timeout): + with state.lock: + if state.managed_calls is not None: + for call in state.managed_calls: + call.cancel() + + channel_spin_thread = _common.CleanupThread( + stop_channel_spin, target=channel_spin) + channel_spin_thread.start() + + +def _create_channel_managed_call(state): + def create_channel_managed_call(parent, flags, method, host, deadline): + """Creates a managed cygrpc.Call. + + Callers of this function must conduct at least one operation on the returned + call. The tags associated with operations conducted on the returned call + must be no-argument callables that return None to indicate that this channel + should continue polling for events associated with the call and return the + call itself to indicate that no more events associated with the call will be + generated. + + Args: + parent: A cygrpc.Call to be used as the parent of the created call. + flags: An integer bitfield of call flags. + method: The RPC method. + host: A host string for the created call. + deadline: A cygrpc.Timespec to be the deadline of the created call. + + Returns: + A cygrpc.Call with which to conduct an RPC. + """ + with state.lock: + call = state.channel.create_call( + parent, flags, state.completion_queue, method, host, deadline) + if state.managed_calls is None: + state.managed_calls = set((call,)) + _run_channel_spin_thread(state) + else: + state.managed_calls.add(call) + return call + return create_channel_managed_call + + +class _ChannelConnectivityState(object): + + def __init__(self, channel): + self.lock = threading.Lock() + self.channel = channel + self.polling = False + self.connectivity = None + self.try_to_connect = False + self.callbacks_and_connectivities = [] + self.delivering = False + + +def _deliveries(state): + callbacks_needing_update = [] + for callback_and_connectivity in state.callbacks_and_connectivities: + callback, callback_connectivity, = callback_and_connectivity + if callback_connectivity is not state.connectivity: + callbacks_needing_update.append(callback) + callback_and_connectivity[1] = state.connectivity + return callbacks_needing_update + + +def _deliver(state, initial_connectivity, initial_callbacks): + connectivity = initial_connectivity + callbacks = initial_callbacks + while True: + for callback in callbacks: + callable_util.call_logging_exceptions( + callback, _CHANNEL_SUBSCRIPTION_CALLBACK_ERROR_LOG_MESSAGE, + connectivity) + with state.lock: + callbacks = _deliveries(state) + if callbacks: + connectivity = state.connectivity + else: + state.delivering = False + return + + +def _spawn_delivery(state, callbacks): + delivering_thread = threading.Thread( + target=_deliver, args=(state, state.connectivity, callbacks,)) + delivering_thread.start() + state.delivering = True + + +# NOTE(https://github.com/grpc/grpc/issues/3064): We'd rather not poll. +def _poll_connectivity(state, channel, initial_try_to_connect): + try_to_connect = initial_try_to_connect + connectivity = channel.check_connectivity_state(try_to_connect) + with state.lock: + state.connectivity = ( + _common.CYGRPC_CONNECTIVITY_STATE_TO_CHANNEL_CONNECTIVITY[ + connectivity]) + callbacks = tuple( + callback for callback, unused_but_known_to_be_none_connectivity + in state.callbacks_and_connectivities) + for callback_and_connectivity in state.callbacks_and_connectivities: + callback_and_connectivity[1] = state.connectivity + if callbacks: + _spawn_delivery(state, callbacks) + completion_queue = cygrpc.CompletionQueue() + while True: + channel.watch_connectivity_state( + connectivity, cygrpc.Timespec(time.time() + 0.2), + completion_queue, None) + event = completion_queue.poll() + with state.lock: + if not state.callbacks_and_connectivities and not state.try_to_connect: + state.polling = False + state.connectivity = None + break + try_to_connect = state.try_to_connect + state.try_to_connect = False + if event.success or try_to_connect: + connectivity = channel.check_connectivity_state(try_to_connect) + with state.lock: + state.connectivity = ( + _common.CYGRPC_CONNECTIVITY_STATE_TO_CHANNEL_CONNECTIVITY[ + connectivity]) + if not state.delivering: + callbacks = _deliveries(state) + if callbacks: + _spawn_delivery(state, callbacks) + + +def _moot(state): + with state.lock: + del state.callbacks_and_connectivities[:] + + +def _subscribe(state, callback, try_to_connect): + with state.lock: + if not state.callbacks_and_connectivities and not state.polling: + def cancel_all_subscriptions(timeout): + _moot(state) + polling_thread = _common.CleanupThread( + cancel_all_subscriptions, target=_poll_connectivity, + args=(state, state.channel, bool(try_to_connect))) + polling_thread.start() + state.polling = True + state.callbacks_and_connectivities.append([callback, None]) + elif not state.delivering and state.connectivity is not None: + _spawn_delivery(state, (callback,)) + state.try_to_connect |= bool(try_to_connect) + state.callbacks_and_connectivities.append( + [callback, state.connectivity]) + else: + state.try_to_connect |= bool(try_to_connect) + state.callbacks_and_connectivities.append([callback, None]) + + +def _unsubscribe(state, callback): + with state.lock: + for index, (subscribed_callback, unused_connectivity) in enumerate( + state.callbacks_and_connectivities): + if callback == subscribed_callback: + state.callbacks_and_connectivities.pop(index) + break + + +def _options(options): + if options is None: + pairs = ((cygrpc.ChannelArgKey.primary_user_agent_string, _USER_AGENT),) + else: + pairs = list(options) + [ + (cygrpc.ChannelArgKey.primary_user_agent_string, _USER_AGENT)] + encoded_pairs = [ + (_common.encode(arg_name), arg_value) if isinstance(arg_value, int) + else (_common.encode(arg_name), _common.encode(arg_value)) + for arg_name, arg_value in pairs] + return cygrpc.ChannelArgs([ + cygrpc.ChannelArg(arg_name, arg_value) + for arg_name, arg_value in encoded_pairs]) + + +class Channel(grpc.Channel): + + def __init__(self, target, options, credentials): + """Constructor. + + Args: + target: The target to which to connect. + options: Configuration options for the channel. + credentials: A cygrpc.ChannelCredentials or None. + """ + self._channel = cygrpc.Channel( + _common.encode(target), _options(options), credentials) + self._call_state = _ChannelCallState(self._channel) + self._connectivity_state = _ChannelConnectivityState(self._channel) + + def subscribe(self, callback, try_to_connect=None): + _subscribe(self._connectivity_state, callback, try_to_connect) + + def unsubscribe(self, callback): + _unsubscribe(self._connectivity_state, callback) + + def unary_unary( + self, method, request_serializer=None, response_deserializer=None): + return _UnaryUnaryMultiCallable( + self._channel, _create_channel_managed_call(self._call_state), + _common.encode(method), request_serializer, response_deserializer) + + def unary_stream( + self, method, request_serializer=None, response_deserializer=None): + return _UnaryStreamMultiCallable( + self._channel, _create_channel_managed_call(self._call_state), + _common.encode(method), request_serializer, response_deserializer) + + def stream_unary( + self, method, request_serializer=None, response_deserializer=None): + return _StreamUnaryMultiCallable( + self._channel, _create_channel_managed_call(self._call_state), + _common.encode(method), request_serializer, response_deserializer) + + def stream_stream( + self, method, request_serializer=None, response_deserializer=None): + return _StreamStreamMultiCallable( + self._channel, _create_channel_managed_call(self._call_state), + _common.encode(method), request_serializer, response_deserializer) + + def __del__(self): + _moot(self._connectivity_state) |