Python zmq.POLLIN Examples

def test_timeout(self):
        """make sure Poller.poll timeout has the right units (milliseconds)."""
        s1, s2 = self.create_bound_pair(zmq.PAIR, zmq.PAIR)
        poller = self.Poller()
        poller.register(s1, zmq.POLLIN)
        tic = time.time()
        evt = poller.poll(.005)
        toc = time.time()
        self.assertTrue(toc-tic < 0.1)
        tic = time.time()
        evt = poller.poll(5)
        toc = time.time()
        self.assertTrue(toc-tic < 0.1)
        self.assertTrue(toc-tic > .001)
        tic = time.time()
        evt = poller.poll(500)
        toc = time.time()
        self.assertTrue(toc-tic < 1)
        self.assertTrue(toc-tic > 0.1) 

def __init__(self, exchange='', addr='ipc:///tmp/feed.ipc', timeout=30):
        """

        :param period: int: Data sampling period
        :param pairs: list: Pair symbols to trade
        :param exchange: str: FeedDaemon exchange to query
        :param addr: str: Client socked address
        :param timeout: int:
        """
        super(DataFeed, self).__init__()

        # Sock objects
        self.context = zmq.Context()
        self.addr = addr
        self.exchange = exchange
        self.timeout = timeout * 1000

        self.sock = self.context.socket(zmq.REQ)
        self.sock.connect(addr)

        self.poll = zmq.Poller()
        self.poll.register(self.sock, zmq.POLLIN) 

def __init__(self, port, pipeline=100, host='localhost', log_file=None):
        """Create a new ZMQDealer object.
        """
        context = zmq.Context.instance()
        # noinspection PyUnresolvedReferences
        self.socket = context.socket(zmq.DEALER)
        self.socket.hwm = pipeline
        self.socket.connect('tcp://%s:%d' % (host, port))
        self._log_file = log_file
        self.poller = zmq.Poller()
        # noinspection PyUnresolvedReferences
        self.poller.register(self.socket, zmq.POLLIN)

        if self._log_file is not None:
            self._log_file = Path(self._log_file).resolve()
            # If log file directory does not exists, create it
            log_dir: Path = self._log_file.parent
            log_dir.mkdir(parents=True, exist_ok=True)
            # time stamp the file
            now = datetime.now()
            time_stamp = now.strftime('%Y%m%d_%H%M%S%f')
            ext = self._log_file.suffix
            self._log_file = str(log_dir / f'{self._log_file.stem}_{time_stamp}{ext}') 

def run(self):
        """ Contents of the infinite loop. """
        # Create zmq sockets
        sockets = SupvisorsZmq(self.supvisors)
        # create poller
        poller = zmq.Poller()
        # register sockets
        poller.register(sockets.internal_subscriber.socket, zmq.POLLIN)
        poller.register(sockets.puller.socket, zmq.POLLIN)
        # poll events forever
        while not self.stopping():
            socks = dict(poller.poll(500))
            # test stop condition again: if Supervisor is stopping,
            # any XML-RPC call would block this thread, and the other
            # because of the join
            if not self.stopping():
                self.check_requests(sockets, socks)
                self.check_events(sockets.internal_subscriber, socks)
        # close resources gracefully
        poller.unregister(sockets.puller.socket)
        poller.unregister(sockets.internal_subscriber.socket)
        sockets.close() 

def check_events(self, subscriber, socks):
        """ Forward external Supervisor events to main thread. """
        if subscriber.socket in socks and \
            socks[subscriber.socket] == zmq.POLLIN:
            try:
                message = subscriber.receive()
            except:
                print >> stderr, '[ERROR] failed to get data from subscriber'
            else:
                # The events received are not processed directly in this thread
                # because it would conflict with the processing in the
                # Supervisor thread, as they use the same data.
                # That's why a RemoteCommunicationEvent is used to push the
                # event in the Supervisor thread.
                self.send_remote_comm_event(
                    RemoteCommEvents.SUPVISORS_EVENT,
                    json.dumps(message)) 

def test_poll_base_socket(self):
        @asyncio.coroutine
        def test():
            ctx = zmq.Context()
            url = 'inproc://test'
            a = ctx.socket(zmq.PUSH)
            b = ctx.socket(zmq.PULL)
            self.sockets.extend([a, b])
            a.bind(url)
            b.connect(url)

            poller = zaio.Poller()
            poller.register(b, zmq.POLLIN)

            f = poller.poll(timeout=1000)
            assert not f.done()
            a.send_multipart([b'hi', b'there'])
            evt = yield from f
            self.assertEqual(evt, [(b, zmq.POLLIN)])
            recvd = b.recv_multipart()
            self.assertEqual(recvd, [b'hi', b'there'])
        self.loop.run_until_complete(test()) 

def test_poll(self):
        @asyncio.coroutine
        def test():
            a, b = self.create_bound_pair(zmq.PUSH, zmq.PULL)
            f = b.poll(timeout=0)
            yield from asyncio.sleep(0)
            self.assertEqual(f.result(), 0)

            f = b.poll(timeout=1)
            assert not f.done()
            evt = yield from f

            self.assertEqual(evt, 0)

            f = b.poll(timeout=1000)
            assert not f.done()
            yield from a.send_multipart([b'hi', b'there'])
            evt = yield from f
            self.assertEqual(evt, zmq.POLLIN)
            recvd = yield from b.recv_multipart()
            self.assertEqual(recvd, [b'hi', b'there'])
        self.loop.run_until_complete(test()) 

def _notify_stream_qt(kernel, stream):

    from IPython.external.qt_for_kernel import QtCore

    if _on_os_x_10_9() and kernel._darwin_app_nap:
        from IPython.external.appnope import nope_scope as context
    else:
        from IPython.core.interactiveshell import NoOpContext as context

    def process_stream_events():
        while stream.getsockopt(zmq.EVENTS) & zmq.POLLIN:
            with context():
                kernel.do_one_iteration()

    fd = stream.getsockopt(zmq.FD)
    notifier = QtCore.QSocketNotifier(fd, QtCore.QSocketNotifier.Read, kernel.app)
    notifier.activated.connect(process_stream_events) 

def _abort_queue(self, stream):
        poller = zmq.Poller()
        poller.register(stream.socket, zmq.POLLIN)
        while True:
            idents,msg = self.session.recv(stream, zmq.NOBLOCK, content=True)
            if msg is None:
                return

            self.log.info("Aborting:")
            self.log.info("%s", msg)
            msg_type = msg['header']['msg_type']
            reply_type = msg_type.split('_')[0] + '_reply'

            status = {'status' : 'aborted'}
            md = {'engine' : self.ident}
            md.update(status)
            reply_msg = self.session.send(stream, reply_type, metadata=md,
                        content=status, parent=msg, ident=idents)
            self.log.debug("%s", reply_msg)
            # We need to wait a bit for requests to come in. This can probably
            # be set shorter for true asynchronous clients.
            poller.poll(50) 

def __send_recv_msg(self, msg):
        # Make sure we're sending bytes instead of strings
        msg = list(map(lambda s: str.encode(s) if type(s) is str else s, msg))
        self.__socket.send_multipart(msg)

        events = dict(self.__poller.poll(SEND_TIMEOUT))
        if events.get(self.__socket) == zmq.POLLIN:
            try:
                # Receive response and make sure the return is converted to string if necessary
                ret_msg = self.__socket.recv_multipart()[0]
                return bytes.decode(ret_msg) if type(ret_msg) is bytes else ret_msg
            except zmq.error.Again:
                # If the receive timed out then return None
                self.__logger.warning("Receive operation timed out!")
                self.__create_socket()
                return None
        else:
            self.__logger.warning("Send operation timed out!")
            self.__create_socket()
            return None 

def check_trigger(self):
        """ Wait to receive the json file and reply with the duration of the
        experiment. Then, to the `queue_trigger_params` the received dict,
        so that the `Experiment` can store it with the rest of the data.
        """

        poller = zmq.Poller()
        poller.register(self.zmq_socket, zmq.POLLIN)
        try:
            self.protocol_duration = self.duration_queue.get(timeout=0.0001)
            print(self.protocol_duration)
        except Empty:
            pass
        if poller.poll(10):
            self.scope_config = self.zmq_socket.recv_json()
            self.device_params_queue.put(self.scope_config)
            self.zmq_socket.send_json(self.protocol_duration)
            return True
        else:
            return False 

def run(self):
        """Start the Authentication Agent thread task"""
        self.authenticator.start()
        self.started.set()
        zap = self.authenticator.zap_socket
        poller = zmq.Poller()
        poller.register(self.pipe, zmq.POLLIN)
        poller.register(zap, zmq.POLLIN)
        while True:
            try:
                socks = dict(poller.poll())
            except zmq.ZMQError:
                break  # interrupted

            if self.pipe in socks and socks[self.pipe] == zmq.POLLIN:
                terminate = self._handle_pipe()
                if terminate:
                    break

            if zap in socks and socks[zap] == zmq.POLLIN:
                self._handle_zap()

        self.pipe.close()
        self.authenticator.stop() 

def _handle_events(self, fd, events):
        """This method is the actual handler for IOLoop, that gets called whenever
        an event on my socket is posted. It dispatches to _handle_recv, etc."""
        if not self.socket:
            gen_log.warning("Got events for closed stream %s", fd)
            return
        zmq_events = self.socket.EVENTS
        try:
            # dispatch events:
            if zmq_events & zmq.POLLIN and self.receiving():
                self._handle_recv()
                if not self.socket:
                    return
            if zmq_events & zmq.POLLOUT and self.sending():
                self._handle_send()
                if not self.socket:
                    return

            # rebuild the poll state
            self._rebuild_io_state()
        except Exception:
            gen_log.error("Uncaught exception in zmqstream callback",
                          exc_info=True)
            raise 

def __init__(self, port, topic='', timeout=0.01):
        """ Constructs the Listener object with a subscriber port
        over which to listen for messages

        :param port: TCP port to listen on
        :param topic: Topic to listen on
        :param timeout: Timeout in seconds to recheck stop flag
        """
        super().__init__()

        self.port = port
        self.topic = topic
        self.context = zmq.Context()
        log.debug("%s has ZMQ Context: %r" % (self.__class__.__name__, self.context))
        self.subscriber = self.context.socket(zmq.SUB)
        self.subscriber.connect('tcp://localhost:%d' % port)
        self.subscriber.setsockopt(zmq.SUBSCRIBE, topic.encode())
        log.info("%s connected to '%s' topic on tcp://localhost:%d" % (
            self.__class__.__name__, topic, port))

        self.poller = zmq.Poller()
        self.poller.register(self.subscriber, zmq.POLLIN)
        self.timeout = timeout 

def _handle_events(self, fd, events):
        """This method is the actual handler for IOLoop, that gets called whenever
        an event on my socket is posted. It dispatches to _handle_recv, etc."""
        if not self.socket:
            gen_log.warning("Got events for closed stream %s", fd)
            return
        zmq_events = self.socket.EVENTS
        try:
            # dispatch events:
            if zmq_events & zmq.POLLIN and self.receiving():
                self._handle_recv()
                if not self.socket:
                    return
            if zmq_events & zmq.POLLOUT and self.sending():
                self._handle_send()
                if not self.socket:
                    return

            # rebuild the poll state
            self._rebuild_io_state()
        except Exception:
            gen_log.error("Uncaught exception in zmqstream callback",
                          exc_info=True)
            raise 

def run(self):
        """Start the Authentication Agent thread task"""
        self.authenticator.start()
        self.started.set()
        zap = self.authenticator.zap_socket
        poller = zmq.Poller()
        poller.register(self.pipe, zmq.POLLIN)
        poller.register(zap, zmq.POLLIN)
        while True:
            try:
                socks = dict(poller.poll())
            except zmq.ZMQError:
                break  # interrupted

            if self.pipe in socks and socks[self.pipe] == zmq.POLLIN:
                terminate = self._handle_pipe()
                if terminate:
                    break

            if zap in socks and socks[zap] == zmq.POLLIN:
                self._handle_zap()

        self.pipe.close()
        self.authenticator.stop() 

def __init__(self, port, topic='', timeout=0.01):
        """ Constructs the Listener object with a subscriber port
        over which to listen for messages

        :param port: TCP port to listen on
        :param topic: Topic to listen on
        :param timeout: Timeout in seconds to recheck stop flag
        """
        super().__init__()

        self.port = port
        self.topic = topic
        self.context = zmq.Context()
        log.debug("%s has ZMQ Context: %r" % (self.__class__.__name__, self.context))
        self.subscriber = self.context.socket(zmq.SUB)
        self.subscriber.connect('tcp://localhost:%d' % port)
        self.subscriber.setsockopt(zmq.SUBSCRIBE, topic.encode())
        log.info("%s connected to '%s' topic on tcp://localhost:%d" % (
            self.__class__.__name__, topic, port))

        self.poller = zmq.Poller()
        self.poller.register(self.subscriber, zmq.POLLIN)
        self.timeout = timeout 

def test_poll_base_socket(self):
        @gen.coroutine
        def test():
            ctx = zmq.Context()
            url = 'inproc://test'
            a = ctx.socket(zmq.PUSH)
            b = ctx.socket(zmq.PULL)
            self.sockets.extend([a, b])
            a.bind(url)
            b.connect(url)

            poller = future.Poller()
            poller.register(b, zmq.POLLIN)

            f = poller.poll(timeout=1000)
            assert not f.done()
            a.send_multipart([b'hi', b'there'])
            evt = yield f
            self.assertEqual(evt, [(b, zmq.POLLIN)])
            recvd = b.recv_multipart()
            self.assertEqual(recvd, [b'hi', b'there'])
            a.close()
            b.close()
            ctx.term()
        self.loop.run_sync(test) 

def reconnect_to_broker(self):
        """Connect or reconnect to broker"""
        if self.worker:
            self.poller.unregister(self.worker)
            self.worker.close()
        self.worker = self.ctx.socket(zmq.DEALER)
        self.worker.linger = 0
        self.worker.connect(self.broker)
        self.poller.register(self.worker, zmq.POLLIN)
        if self.verbose:
            logging.info("I: connecting to broker at %s…", self.broker)

        # Register service with broker
        self.send_to_broker(MDP.W_READY, pickle.dumps(self.service), [])

        # If liveness hits zero, queue is considered disconnected
        self.liveness = self.HEARTBEAT_LIVENESS
        self.heartbeat_at = time.time() + 1e-3 * self.heartbeat 

def support_test_send_to_multiple_addresses(self, address1, address2):
        poller = zmq.Poller()

        socket1 = self.context.socket(roles['listener'])
        socket2 = self.context.socket(roles['listener'])
        try:
            socket1.bind("tcp://%s" % address1)
            socket2.bind("tcp://%s" % address2)
            poller.register(socket1, zmq.POLLIN)
            poller.register(socket2, zmq.POLLIN)
            polled = dict(poller.poll(2000))
            if socket1 in polled:
                socket1.recv()
                socket1.send(nw0.sockets._serialise(address1))
            elif socket2 in polled:
                socket2.recv()
                socket2.send(nw0.sockets._serialise(address2))
            else:
                raise RuntimeError("Nothing found")
        finally:
            socket1.close()
            socket2.close() 

def _add_recv_event(self, kind, kwargs=None, future=None):
        """Add a recv event, returning the corresponding Future"""
        f = future or self._Future()
        if kind.startswith('recv') and kwargs.get('flags', 0) & _zmq.DONTWAIT:
            # short-circuit non-blocking calls
            recv = getattr(self._shadow_sock, kind)
            try:
                r = recv(**kwargs)
            except Exception as e:
                f.set_exception(e)
            else:
                f.set_result(r)
            return f

        # we add it to the list of futures before we add the timeout as the
        # timeout will remove the future from recv_futures to avoid leaks
        self._recv_futures.append(
            _FutureEvent(f, kind, kwargs, msg=None)
        )

        # Don't let the Future sit in _recv_events after it's done
        f.add_done_callback(lambda f: self._remove_finished_future(f, self._recv_futures))

        if hasattr(_zmq, 'RCVTIMEO'):
            timeout_ms = self._shadow_sock.rcvtimeo
            if timeout_ms >= 0:
                self._add_timeout(f, timeout_ms * 1e-3)

        if self._shadow_sock.EVENTS & POLLIN:
            # recv immediately, if we can
            self._handle_recv()
        if self._recv_futures:
            self._add_io_state(POLLIN)
        return f 

def _rebuild_io_state(self):
        """rebuild io state based on self.sending() and receiving()"""
        if self.socket is None:
            return
        state = 0
        if self.receiving():
            state |= zmq.POLLIN
        if self.sending():
            state |= zmq.POLLOUT

        self._state = state
        self._update_handler(state) 

def _wait_read(self):
        assert self.__readable.ready(), "Only one greenlet can be waiting on this event"
        self.__readable = AsyncResult()
        # timeout is because libzmq cannot always be trusted to play nice with libevent.
        # I can only confirm that this actually happens for send, but lets be symmetrical
        # with our dirty hacks.
        # this is effectively a maximum poll interval of 1s
        tic = time.time()
        dt = self._gevent_bug_timeout
        if dt:
            timeout = gevent.Timeout(seconds=dt)
        else:
            timeout = None
        try:
            if timeout:
                timeout.start()
            self.__readable.get(block=True)
        except gevent.Timeout as t:
            if t is not timeout:
                raise
            toc = time.time()
            # gevent bug: get can raise timeout even on clean return
            # don't display zmq bug warning for gevent bug (this is getting ridiculous)
            if self._debug_gevent and timeout and toc-tic > dt and \
                    self.getsockopt(zmq.EVENTS) & zmq.POLLIN:
                print("BUG: gevent may have missed a libzmq recv event on %i!" % self.FD, file=sys.stderr)
        finally:
            if timeout:
                timeout.cancel()
            self.__readable.set() 

def _create_socket(self):
        if self.socket is not None:
            # close previous socket, before opening a new one
            self.poller.unregister(self.socket)
            self.socket.close()
        self.socket = self.context.socket(zmq.REQ)
        self.socket.setsockopt(zmq.LINGER, 0)
        self.socket.connect(self.address)

        self.poller.register(self.socket, zmq.POLLIN) 

def do_one_iteration(self):
        """step eventloop just once"""
        InteractiveShell.set_instance(self.shell)
        if self.control_stream:
            self.control_stream.flush()
        for stream in self.shell_streams:
            # handle at most one request per iteration
            stream.flush(zmq.POLLIN, 1)
            stream.flush(zmq.POLLOUT) 

def _setup_pipe_in(self):
        """setup listening pipe for subprocesses"""
        ctx = self.pub_socket.context
        
        # use UUID to authenticate pipe messages
        self._pipe_uuid = uuid.uuid4().bytes
        
        self._pipe_in = ctx.socket(zmq.PULL)
        self._pipe_in.linger = 0
        self._pipe_port = self._pipe_in.bind_to_random_port("tcp://127.0.0.1")
        self._pipe_poller = zmq.Poller()
        self._pipe_poller.register(self._pipe_in, zmq.POLLIN) 

def monitored_queue(in_socket, out_socket, mon_socket,
                    in_prefix=b'in', out_prefix=b'out'):
    
    swap_ids = in_socket.type == zmq.ROUTER and out_socket.type == zmq.ROUTER
    
    poller = zmq.Poller()
    poller.register(in_socket, zmq.POLLIN)
    poller.register(out_socket, zmq.POLLIN)
    while True:
        events = dict(poller.poll())
        if in_socket in events:
            _relay(in_socket, out_socket, mon_socket, in_prefix, swap_ids)
        if out_socket in events:
            _relay(out_socket, in_socket, mon_socket, out_prefix, swap_ids) 

def _get_descriptors(self):
        """Returns three elements tuple with socket descriptors ready
        for gevent.select.select
        """
        rlist = []
        wlist = []
        xlist = []

        for socket, flags in self.sockets:
            if isinstance(socket, zmq.Socket):
                rlist.append(socket.getsockopt(zmq.FD))
                continue
            elif isinstance(socket, int):
                fd = socket
            elif hasattr(socket, 'fileno'):
                try:
                    fd = int(socket.fileno())
                except:
                    raise ValueError('fileno() must return an valid integer fd')
            else:
                raise TypeError('Socket must be a 0MQ socket, an integer fd '
                                'or have a fileno() method: %r' % socket)

            if flags & zmq.POLLIN:
                rlist.append(fd)
            if flags & zmq.POLLOUT:
                wlist.append(fd)
            if flags & zmq.POLLERR:
                xlist.append(fd)

        return (rlist, wlist, xlist) 

def device(device_type, isocket, osocket):
    """Start a zeromq device (gevent-compatible).
    
    Unlike the true zmq.device, this does not release the GIL.

    Parameters
    ----------
    device_type : (QUEUE, FORWARDER, STREAMER)
        The type of device to start (ignored).
    isocket : Socket
        The Socket instance for the incoming traffic.
    osocket : Socket
        The Socket instance for the outbound traffic.
    """
    p = Poller()
    if osocket == -1:
        osocket = isocket
    p.register(isocket, zmq.POLLIN)
    p.register(osocket, zmq.POLLIN)
    
    while True:
        events = dict(p.poll())
        if isocket in events:
            osocket.send_multipart(isocket.recv_multipart())
        if osocket in events:
            isocket.send_multipart(osocket.recv_multipart()) 

def __state_changed(self, event=None, _evtype=None):
        if self.closed:
            self.__cleanup_events()
            return
        try:
            # avoid triggering __state_changed from inside __state_changed
            events = super(_Socket, self).getsockopt(zmq.EVENTS)
        except zmq.ZMQError as exc:
            self.__writable.set_exception(exc)
            self.__readable.set_exception(exc)
        else:
            if events & zmq.POLLOUT:
                self.__writable.set()
            if events & zmq.POLLIN:
                self.__readable.set()