Method _do_poll_problems

dwave/cloud/client/base.py:1641–1765

Poll the server for the status of a set of problems. Note: This method is always run inside of a daemon thread.

(self)

        self._poll_queue.put((created_at, future))

    def _do_poll_problems(self):
        """Poll the server for the status of a set of problems.

        Note:
            This method is always run inside of a daemon thread.
        """
        session = self.create_session()
        session.set_accept(media_type='application/vnd.dwave.sapi.problems+json',
                           accept_version='~=3.0', ask_version='3.0.0')
        try:
            # grouped futures (all scheduled within _POLL_GROUP_TIMEFRAME)
            # and/or up to _STATUS_QUERY_SIZE (depending on strategy)
            frame_futures = {}

            use_long_polling = (
                self.config.polling_schedule.strategy == PollingStrategy.LONG_POLLING)

            def task_done():
                self._poll_queue.task_done()

            def add(future):
                # add future to query frame_futures
                # returns: worker lives on?

                # `None` task signifies thread termination
                if future is None:
                    task_done()
                    return False

                if future.id not in frame_futures and not future.done():
                    frame_futures[future.id] = future
                else:
                    task_done()

                return True

            while True:
                frame_futures.clear()

                # blocking add first scheduled
                frame_earliest, future = self._poll_queue.get()
                if not add(future):
                    return

                # try grouping if scheduled within grouping timeframe
                # (or in the long polling case, add up to _STATUS_QUERY_SIZE available futures)
                while len(frame_futures) < self._STATUS_QUERY_SIZE:
                    try:
                        task = self._poll_queue.get_nowait()
                    except queue.Empty:
                        break

                    at, future = task
                    if use_long_polling or (at - frame_earliest <= self._POLL_GROUP_TIMEFRAME):
                        if not add(future):
                            return
                    else:
                        self._poll_queue.put(task)