def run_once(self, *args, **kwargs):
        self.get_process_values(kwargs)
        pool = GreenPool(self.concurrency)
        containers_to_delete = set([])
        self.report_first_time = self.report_last_time = time()
        self.report_objects = 0
        try:
            self.logger.debug('Run begin')
            containers, objects = \
                self.swift.get_account_info(self.expiring_objects_account)
            self.logger.info(_('Pass beginning; %s possible containers; %s '
                               'possible objects') % (containers, objects))

            for container, obj in self.iter_cont_objs_to_expire():
                containers_to_delete.add(container)

                if not obj:
                    continue

                timestamp, actual_obj = obj.split('-', 1)
                timestamp = int(timestamp)
                if timestamp > int(time()):
                    break
                pool.spawn_n(
                    self.delete_object, actual_obj, timestamp,
                    container, obj)

            pool.waitall()
            for container in containers_to_delete:
                try:
                    self.swift.delete_container(
                        self.expiring_objects_account,
                        container,
                        acceptable_statuses=(2, HTTP_NOT_FOUND, HTTP_CONFLICT))
                except (Exception, Timeout) as err:
                    self.logger.exception(
                        _('Exception while deleting container %(container)s '
                          '%(err)s') % {'container': container,
                                        'err': str(err)})
            self.logger.debug('Run end')
            self.report(final=True)
        except (Exception, Timeout):
            self.logger.exception(_('Unhandled exception'))
Executes a single pass, looking for objects to expire.
dataset/ETHPy150Open openstack/swift/swift/obj/expirer.py/ObjectExpirer.run_once