Python concurrent.futures.CancelledError() Examples

def serve_forever(self):
        if self._serving_forever_fut is not None:
            raise RuntimeError(
                f'server {self!r} is already being awaited on serve_forever()')
        if self._sockets is None:
            raise RuntimeError(f'server {self!r} is closed')

        self._start_serving()
        self._serving_forever_fut = self._loop.create_future()

        try:
            await self._serving_forever_fut
        except futures.CancelledError:
            try:
                self.close()
                await self.wait_closed()
            finally:
                raise
        finally:
            self._serving_forever_fut = None 

def wait(self, timeout=None):
        """Block until the internal flag is true.

        Returns a Future, which raises `tornado.util.TimeoutError` after a
        timeout.
        """
        fut = Future()
        if self._value:
            fut.set_result(None)
            return fut
        self._waiters.add(fut)
        fut.add_done_callback(lambda fut: self._waiters.remove(fut))
        if timeout is None:
            return fut
        else:
            timeout_fut = gen.with_timeout(timeout, fut, quiet_exceptions=(CancelledError,))
            # This is a slightly clumsy workaround for the fact that
            # gen.with_timeout doesn't cancel its futures. Cancelling
            # fut will remove it from the waiters list.
            timeout_fut.add_done_callback(lambda tf: fut.cancel() if not fut.done() else None)
            return timeout_fut 

def wait(self, timeout: Union[float, datetime.timedelta] = None) -> Awaitable[None]:
        """Block until the internal flag is true.

        Returns an awaitable, which raises `tornado.util.TimeoutError` after a
        timeout.
        """
        fut = Future()  # type: Future[None]
        if self._value:
            fut.set_result(None)
            return fut
        self._waiters.add(fut)
        fut.add_done_callback(lambda fut: self._waiters.remove(fut))
        if timeout is None:
            return fut
        else:
            timeout_fut = gen.with_timeout(
                timeout, fut, quiet_exceptions=(CancelledError,)
            )
            # This is a slightly clumsy workaround for the fact that
            # gen.with_timeout doesn't cancel its futures. Cancelling
            # fut will remove it from the waiters list.
            timeout_fut.add_done_callback(
                lambda tf: fut.cancel() if not fut.done() else None
            )
            return timeout_fut 

def run(self):
        while not self.closed:
            try:
                segment, future = self.futures.get(block=True, timeout=0.5)
            except queue.Empty:
                continue

            # End of stream
            if future is None:
                break

            while not self.closed:
                try:
                    result = future.result(timeout=0.5)
                except futures.TimeoutError:
                    continue
                except futures.CancelledError:
                    break

                if result is not None:
                    self.write(segment, result)

                break

        self.close() 

def wait(self, timeout: Union[float, datetime.timedelta] = None) -> Awaitable[None]:
        """Block until the internal flag is true.

        Returns an awaitable, which raises `tornado.util.TimeoutError` after a
        timeout.
        """
        fut = Future()  # type: Future[None]
        if self._value:
            fut.set_result(None)
            return fut
        self._waiters.add(fut)
        fut.add_done_callback(lambda fut: self._waiters.remove(fut))
        if timeout is None:
            return fut
        else:
            timeout_fut = gen.with_timeout(
                timeout, fut, quiet_exceptions=(CancelledError,)
            )
            # This is a slightly clumsy workaround for the fact that
            # gen.with_timeout doesn't cancel its futures. Cancelling
            # fut will remove it from the waiters list.
            timeout_fut.add_done_callback(
                lambda tf: fut.cancel() if not fut.done() else None
            )
            return timeout_fut 

def _receive_credential(self, result_type: CredentialType) -> Optional[str]:
        if self.cancelled:
            return None
        self.current_status = {
            "next_step": result_type.value,
        }
        if result_type == CredentialType.AUTHORIZATION:
            self.current_status["manual_auth_url"] = make_login_url(self.device_name)
        try:
            return self.queue.send_to_async(self.current_status,
                                            lambda: self._set_expecting(result_type))
        except futures.TimeoutError:
            self.cancel()
            return None
        except futures.CancelledError:
            return None 

def test_recv_json_cancelled(self):
        @asyncio.coroutine
        def test():
            a, b = self.create_bound_pair(zmq.PUSH, zmq.PULL)
            f = b.recv_json()
            assert not f.done()
            f.cancel()
            # cycle eventloop to allow cancel events to fire
            yield from asyncio.sleep(0)
            obj = dict(a=5)
            yield from a.send_json(obj)
            with pytest.raises(CancelledError):
                recvd = yield from f
            assert f.done()
            # give it a chance to incorrectly consume the event
            events = yield from b.poll(timeout=5)
            assert events
            yield from asyncio.sleep(0)
            # make sure cancelled recv didn't eat up event
            f = b.recv_json()
            recvd = yield from asyncio.wait_for(f, timeout=5)
            assert recvd == obj
        self.loop.run_until_complete(test()) 

def test_server(self):

        host = "0.0.0.0"
        port = 5489
        socket_timeout = 60

        def timeout_server():
            # need a more robust mechanism for when to cancel the future
            time.sleep(2)
            self.stop_server_future.cancel()

        thread = threading.Thread(target=timeout_server)
        thread.daemon = True
        thread.start()

        with self.assertRaises(CancelledError):
            start_server(host=host, port=port,
                         loop=self.loop,
                         socket_timeout=socket_timeout,
                         stop_server_future=self.stop_server_future) 

def wait(self, timeout: Union[float, datetime.timedelta] = None) -> Awaitable[None]:
        """Block until the internal flag is true.

        Returns an awaitable, which raises `tornado.util.TimeoutError` after a
        timeout.
        """
        fut = Future()  # type: Future[None]
        if self._value:
            fut.set_result(None)
            return fut
        self._waiters.add(fut)
        fut.add_done_callback(lambda fut: self._waiters.remove(fut))
        if timeout is None:
            return fut
        else:
            timeout_fut = gen.with_timeout(
                timeout, fut, quiet_exceptions=(CancelledError,)
            )
            # This is a slightly clumsy workaround for the fact that
            # gen.with_timeout doesn't cancel its futures. Cancelling
            # fut will remove it from the waiters list.
            timeout_fut.add_done_callback(
                lambda tf: fut.cancel() if not fut.done() else None
            )
            return timeout_fut 

def submit(self, label, command, opts):
        """Submit a bgutil command to run it asynchronously."""
        task = BgUtilTask(label, datetime.now())
        self.tasks.append(task)

        def _done_callback(f):
            try:
                result = f.result()
                task.completed(result)
            except futures.CancelledError as e:
                task.cancelled(e)
            except futures.TimeoutError as e:
                task.timed_out(e)
            except Exception as e:
                task.failed(e)

        future = self._executor.submit(
            self._wrap_command, task, context.accessor, command, opts
        )
        task.submitted()
        future.add_done_callback(_done_callback) 

def start(self):
        try:
            if not self.isConnected():
                await self._connect()
            while self.isConnected():
                await self.client.parse()
        except CancelledError:
            pass
        except Exception as err:
            exc_type, exc_value, exc_traceback = sys.exc_info()
            traceback.print_exception(exc_type, exc_value, exc_traceback)
            log.info("FICSConnection.run: %s" % repr(err),
                     extra={"task": (self.host, "raw")})
            self.close()
            if isinstance(err,
                          (IOError, LogOnException, EOFError, socket.error,
                           socket.gaierror, socket.herror)):
                self.emit("error", err)
            else:
                raise
        finally:
            if isinstance(self, FICSMainConnection):
                self.emit("disconnected") 

def _do_heartbeat(self):
        while True:
            try:
                if self._socket.getsockopt(zmq.TYPE) == zmq.ROUTER:
                    yield from self._do_router_heartbeat()
                elif self._socket.getsockopt(zmq.TYPE) == zmq.DEALER:
                    yield from self._do_dealer_heartbeat()
                yield from asyncio.sleep(self._heartbeat_interval,
                                         loop=self._event_loop)
            except CancelledError:  # pylint: disable=try-except-raise
                # The concurrent.futures.CancelledError is caught by asyncio
                # when the Task associated with the coroutine is cancelled.
                # The raise is required to stop this component.
                raise
            except Exception as e:  # pylint: disable=broad-except
                LOGGER.exception(
                    "An error occurred while sending heartbeat: %s", e) 

def start_login(self, request: web.Request) -> web.Response:
        user_id = self.verify_token(request)
        manual = request.query.get("manual")
        if manual and (manual == "1" or manual.lower() == "true"):
            manual = True
        else:
            manual = False
        user = u.User.get_by_mxid(user_id)
        if user.client:
            return web.json_response({
                "status": "success",
                "name": await user.name_future,
            })
        try:
            return web.json_response(self.ongoing[user.mxid].current_status)
        except KeyError:
            pass
        login = WebCredentialsPrompt(self, user, manual, self.device_name, self.loop)
        self.ongoing[user.mxid] = login
        try:
            return web.json_response(await login.start())
        except asyncio.CancelledError:
            raise ErrorResponse(410, "Login cancelled", "HANGOUTS_LOGIN_CANCELLED") 

def test_recv_json_cancelled(self):
        @asyncio.coroutine
        def test():
            a, b = self.create_bound_pair(zmq.PUSH, zmq.PULL)
            f = b.recv_json()
            assert not f.done()
            f.cancel()
            # cycle eventloop to allow cancel events to fire
            yield from asyncio.sleep(0)
            obj = dict(a=5)
            yield from a.send_json(obj)
            with pytest.raises(CancelledError):
                recvd = yield from f
            assert f.done()
            # give it a chance to incorrectly consume the event
            events = yield from b.poll(timeout=5)
            assert events
            yield from asyncio.sleep(0)
            # make sure cancelled recv didn't eat up event
            f = b.recv_json()
            recvd = yield from asyncio.wait_for(f, timeout=5)
            assert recvd == obj
        self.loop.run_until_complete(test()) 

def wait(self, timeout=None):
        """Block until the internal flag is true.

        Returns a Future, which raises `tornado.util.TimeoutError` after a
        timeout.
        """
        fut = Future()
        if self._value:
            fut.set_result(None)
            return fut
        self._waiters.add(fut)
        fut.add_done_callback(lambda fut: self._waiters.remove(fut))
        if timeout is None:
            return fut
        else:
            timeout_fut = gen.with_timeout(timeout, fut, quiet_exceptions=(CancelledError,))
            # This is a slightly clumsy workaround for the fact that
            # gen.with_timeout doesn't cancel its futures. Cancelling
            # fut will remove it from the waiters list.
            timeout_fut.add_done_callback(lambda tf: fut.cancel() if not fut.done() else None)
            return timeout_fut 

def serve_forever(self):
        if self._serving_forever_fut is not None:
            raise RuntimeError(
                f'server {self!r} is already being awaited on serve_forever()')
        if self._sockets is None:
            raise RuntimeError(f'server {self!r} is closed')

        self._start_serving()
        self._serving_forever_fut = self._loop.create_future()

        try:
            await self._serving_forever_fut
        except futures.CancelledError:
            try:
                self.close()
                await self.wait_closed()
            finally:
                raise
        finally:
            self._serving_forever_fut = None 

def websocket_handler(request):
    """Handle a new socket connection."""

    logger.debug('New websocket connection.')
    websocket = web.WebSocketResponse()
    yield from websocket.prepare(request)
    uuid = uuid4()
    request.app['dispatcher'].subscribe(uuid, websocket)

    while True:
        # Consume input buffer
        try:
            msg = yield from websocket.receive()
        except RuntimeError as e:
            logger.debug('Websocket exception: %s', str(e))
            break
        except CancelledError:
            logger.debug('Websocket closed')
            break
        if msg.type == aiohttp.WSMsgType.CLOSED:
            logger.debug('Websocket closed')
            break
        elif msg.type == aiohttp.WSMsgType.ERROR:
            logger.debug('Websocket exception: %s', websocket.exception())
            break

    request.app['dispatcher'].unsubscribe(uuid)
    return websocket 

def invoke_sync(self, interface, method, content, *, spanctx, timeout_ms, **headers):
        """blocking call to interface, returns responsepkg.content(as bytes)"""
        assert isinstance(timeout_ms, (int, float))
        header = SofaHeader.build_header(spanctx, interface, method, **headers)
        pkg = BoltRequest.new_request(header, content, timeout_ms=timeout_ms)
        fut = asyncio.run_coroutine_threadsafe(self.invoke(pkg), loop=self._loop)
        try:
            ret = fut.result(timeout=timeout_ms / 1000)
        except (TimeoutError, CancelledError) as e:
            logger.error("call to [{}:{}] timeout/cancelled. {}".format(interface, method, e))
            raise
        return ret.content 

def cancel(self):
        """Request that this task cancel itself.

        This arranges for a CancelledError to be thrown into the
        wrapped coroutine on the next cycle through the event loop.
        The coroutine then has a chance to clean up or even deny
        the request using try/except/finally.

        Unlike Future.cancel, this does not guarantee that the
        task will be cancelled: the exception might be caught and
        acted upon, delaying cancellation of the task or preventing
        cancellation completely.  The task may also return a value or
        raise a different exception.

        Immediately after this method is called, Task.cancelled() will
        not return True (unless the task was already cancelled).  A
        task will be marked as cancelled when the wrapped coroutine
        terminates with a CancelledError exception (even if cancel()
        was not called).
        """
        self._log_traceback = False
        if self.done():
            return False
        if self._fut_waiter is not None:
            if self._fut_waiter.cancel():
                # Leave self._fut_waiter; it may be a Task that
                # catches and ignores the cancellation so we may have
                # to cancel it again later.
                return True
        # It must be the case that self._step is already scheduled.
        self._must_cancel = True
        return True 

def test_trio_future_cancelled():
    fut = Future()

    async def do_set():
        fut.cancel()

    async with trio.open_nursery() as nursery:
        nursery.start_soon(do_set)
        with pytest.raises(CancelledError):
            await fut 

def websocket_handler(request):
    """Handle a new socket connection."""

    logger.debug('New websocket connection.')
    websocket = web.WebSocketResponse()
    yield from websocket.prepare(request)
    uuid = uuid4()
    request.app['dispatcher'].subscribe(uuid, websocket)

    while True:
        # Consume input buffer
        try:
            msg = yield from websocket.receive()
        except RuntimeError as e:
            logger.debug('Websocket exception: %s', str(e))
            break
        except CancelledError:
            logger.debug('Websocket closed')
            break
        if msg.type == aiohttp.WSMsgType.CLOSED:
            logger.debug('Websocket closed')
            break
        elif msg.type == aiohttp.WSMsgType.ERROR:
            logger.debug('Websocket exception: %s', websocket.exception())
            break

    request.app['dispatcher'].unsubscribe(uuid)
    return websocket 

def _recv_response(self, reader, writer):
        """
        wait response and put it in response_mapping, than notify the invoke coro
        :param reader:
        :return:
        """
        while True:
            pkg = None
            try:
                fixed_header_bs = await reader.readexactly(BoltResponse.bolt_header_size())
                header = BoltResponse.bolt_header_from_stream(fixed_header_bs)
                bs = await reader.readexactly(header['class_len'] + header['header_len'] + header['content_len'])
                pkg = BoltResponse.bolt_content_from_stream(bs, header)
                if pkg.class_name != BoltResponse.class_name:
                    raise ServerError("wrong class_name:[{}]".format(pkg.class_name))
                if pkg.cmdcode == CMDCODE.HEARTBEAT:
                    continue
                elif pkg.cmdcode == CMDCODE.REQUEST:
                    # raise error, the connection will be dropped
                    raise ServerError("wrong cmdcode:[{}]".format(pkg.cmdcode))
                if pkg.respstatus != RESPSTATUS.SUCCESS:
                    raise ServerError.from_statuscode(pkg.respstatus)
                if pkg.request_id not in self.request_mapping:
                    continue
                self.response_mapping[pkg.request_id] = pkg

            except PyboltError as e:
                logger.error(e)
            except (asyncio.CancelledError, EOFError, ConnectionResetError) as e:
                logger.error(e)
                writer.close()
                break
            except Exception:
                logger.error(traceback.format_exc())
                writer.close()
                break
            finally:
                with suppress(AttributeError, KeyError):
                    # wake up the coro
                    event = self.request_mapping.pop(pkg.request_id)
                    event.set() 

def wait(self, _timeout=None):
        if self._awaited:
            try:
                self._future.result(timeout=_timeout)
            except FutureTimeoutError:
                self.set_timedout()
            except FutureCancelledError:
                self.cancel()
        return self 

def __exit__(self, exc_type, exc_val, exc_tb):
        if exc_type is futures.CancelledError and self._cancelled:
            self._cancel_handler = None
            self._task = None
            raise futures.TimeoutError
        self._cancel_handler.cancel()
        self._cancel_handler = None
        self._task = None 

def test_result_with_timeout(self):
        self.assertRaises(futures.TimeoutError,
                          PENDING_FUTURE.result, timeout=0)
        self.assertRaises(futures.TimeoutError,
                          RUNNING_FUTURE.result, timeout=0)
        self.assertRaises(futures.CancelledError,
                          CANCELLED_FUTURE.result, timeout=0)
        self.assertRaises(futures.CancelledError,
                          CANCELLED_AND_NOTIFIED_FUTURE.result, timeout=0)
        self.assertRaises(OSError, EXCEPTION_FUTURE.result, timeout=0)
        self.assertEqual(SUCCESSFUL_FUTURE.result(timeout=0), 42) 

def cancel(self):
        """Request that this task cancel itself.

        This arranges for a CancelledError to be thrown into the
        wrapped coroutine on the next cycle through the event loop.
        The coroutine then has a chance to clean up or even deny
        the request using try/except/finally.

        Unlike Future.cancel, this does not guarantee that the
        task will be cancelled: the exception might be caught and
        acted upon, delaying cancellation of the task or preventing
        cancellation completely.  The task may also return a value or
        raise a different exception.

        Immediately after this method is called, Task.cancelled() will
        not return True (unless the task was already cancelled).  A
        task will be marked as cancelled when the wrapped coroutine
        terminates with a CancelledError exception (even if cancel()
        was not called).
        """
        if self.done():
            return False
        if self._fut_waiter is not None:
            if self._fut_waiter.cancel():
                # Leave self._fut_waiter; it may be a Task that
                # catches and ignores the cancellation so we may have
                # to cancel it again later.
                return True
        # It must be the case that self._step is already scheduled.
        self._must_cancel = True
        return True 

def test_set_model_exception_metadata_exception():
    """Tests cases where accessing metadata throws exceptions
    """
    # State "running" prevents termination when the object is created.
    mock_client = setup_client_mock(1, 2, state='running')

    class ModelFutureRaiseExc(_model.ModelFuture):
        def __init__(self, exc, *args, **kwargs):
            self.__exc = exc
            super().__init__(*args, **kwargs)

        @property
        def metadata(self):
            raise self.__exc('What a spectacular failure, you say!')

    # exception types get caught!
    for exc in [FileNotFoundError, CivisJobFailure, CancelledError]:
        fut = ModelFutureRaiseExc(exc, 1, 2, client=mock_client)
        _model.ModelFuture._set_model_exception(fut)

    with pytest.warns(UserWarning):
        # The KeyError is caught, but sends a warning
        fut = ModelFutureRaiseExc(KeyError, 1, 2, client=mock_client)
        _model.ModelFuture._set_model_exception(fut)

    fut = ModelFutureRaiseExc(RuntimeError, 1, 2, client=mock_client)
    with pytest.raises(RuntimeError):
        _model.ModelFuture._set_model_exception(fut) 

def test_result_with_cancel(self):
        # TODO(brian@sweetapp.com): This test is timing dependent.
        def notification():
            # Wait until the main thread is waiting for the result.
            time.sleep(1)
            f1.cancel()

        f1 = create_future(state=PENDING)
        t = threading.Thread(target=notification)
        t.start()

        self.assertRaises(futures.CancelledError, f1.result, timeout=5) 

def handle_exit(client):
    client.loop.create_task(client.logout())
    for t in asyncio.Task.all_tasks(loop=client.loop):
        if t.done():
            t.exception()
            continue
        t.cancel()
        try:
            client.loop.run_until_complete(asyncio.wait_for(t, 5, loop=client.loop))
            t.exception()
        except (InvalidStateError, TimeoutError, asyncio.CancelledError, futures.CancelledError):
            pass
        except:
            traceback.print_exc() 

def websocket_handler(request):
    """Handle a new socket connection."""

    logger.debug('New websocket connection.')
    websocket = web.WebSocketResponse()
    yield from websocket.prepare(request)
    uuid = uuid4()
    request.app['dispatcher'].subscribe(uuid, websocket)

    while True:
        # Consume input buffer
        try:
            msg = yield from websocket.receive()
        except RuntimeError as e:
            logger.debug('Websocket exception: %s', str(e))
            break
        except CancelledError:
            logger.debug('Websocket closed')
            break
        if msg.type == aiohttp.WSMsgType.CLOSED:
            logger.debug('Websocket closed')
            break
        elif msg.type == aiohttp.WSMsgType.ERROR:
            logger.debug('Websocket exception: %s', websocket.exception())
            break

    request.app['dispatcher'].unsubscribe(uuid)
    return websocket