code: def worker_loop(
      queue,
      parsed_args,
      single_experiment=False,
      timeout=0,
      verbose=None,
  ):
      fetch_artifacts = True
  
      logger = logs.get_logger("worker_loop")
  
      hold_period = 4
      retval = 0
      while True:
          msg = queue.dequeue(acknowledge=False, timeout=timeout)
          if not msg:
              break
  
          first_exp, ack_key = msg
  
          data_dict = json.loads(sixdecode(first_exp))
          experiment_key = data_dict["experiment"]["key"]
          config = data_dict["config"]
  
          parsed_args.config = config
          if verbose:
              config["verbose"] = verbose
          else:
              verbose = model.parse_verbosity(
                  config.get("verbose", None)
              )
  
          logger.setLevel(verbose)
  
          logger.debug("Received message: \n{}".format(data_dict))
  
          executor = LocalExecutor(queue, parsed_args)
  
          with model.get_db_provider(config) as db:
              # experiment = experiment_from_dict(data_dict['experiment'])
              def try_get_experiment():
                  experiment = db.get_experiment(experiment_key)
                  if experiment is None:
                      raise ValueError(
                          "experiment is not found - indicates storage failure"
                      )
                  return experiment
  
              experiment = retry(
                  try_get_experiment, sleep_time=10, logger=logger
              )
  
              if (
                  config.get("experimentLifetime", None)
                  and int(
                      str2duration(
                          config["experimentLifetime"]
                      ).total_seconds()
                  )
                  + experiment.time_added
                  < time.time()
              ):
                  logger.info(
                      "Experiment expired (max lifetime of {0} was exceeded)".format(
                          config.get("experimentLifetime", None)
                      )
                  )
                  queue.acknowledge(ack_key)
                  continue
  
              if allocate_resources(
                  experiment, config, verbose=verbose
              ):
  
                  def hold_job():
                      queue.hold(ack_key, hold_period)
  
                  hold_job()
                  sched = BackgroundScheduler()
                  sched.add_job(
                      hold_job, "interval", minutes=hold_period / 2
                  )
                  sched.start()
  
                  try:
                      python = "python"
                      if experiment.pythonver[0] == "3":
                          python = "python3"
                      if (
                          "_singularity"
                          not in experiment.artifacts.keys()
                      ):
                          pip_diff = pip_needed_packages(
                              experiment.pythonenv, python
                          )
                          if any(pip_diff):
                              logger.info(
                                  "Setting up python packages for experiment"
                              )
                              if (
                                  pip_install_packages(
                                      pip_diff, python, logger
                                  )
                                  != 0
                              ):
                                  logger.info(
                                      "Installation of all packages together "
                                      + " failed, "
                                      "trying one package at a time"
                                  )
  
                                  for pkg in pip_diff:
                                      pip_install_packages(
                                          [pkg], python, logger
                                      )
  
                      for tag, item in experiment.artifacts.items():
                          art: Artifact = item
                          if fetch_artifacts or art.local_path is None:
                              get_only_newer: bool = True
                              if tag == "workspace":
                                  get_only_newer = False
  
                              if not art.is_mutable:
                                  logger.info(
                                      "Fetching artifact " + tag
                                  )
                                  art.local_path = retry(
                                      lambda: db.get_artifact(
                                          art, only_newer=get_only_newer
                                      ),
                                      sleep_time=10,
                                      logger=logger,
                                  )
                              else:
                                  logger.info(
                                      "Skipping mutable artifact " + tag
                                  )
  
                      returncode = executor.run(experiment)
                      if returncode != 0:
                          retval = returncode
                  finally:
                      sched.shutdown()
                      queue.acknowledge(ack_key)
  
                  if single_experiment:
                      logger.info("single_experiment is True, quitting")
                      return retval
              else:
                  logger.info(
                      "Cannot run experiment "
                      + experiment.key
                      + " due lack of resources. Will retry"
                  )
                  # Debounce failed requests we cannot service yet
                  time.sleep(config.get("sleep_time", 5))
  
      logger.info(
          "Queue in {0} is empty, quitting".format(
              fs_tracker.get_queue_directory()
          )
      )
  
      return retval
  
imports: import os
  import sys
  import subprocess
  import argparse
  import json
  import psutil
  import time
  import six
  import signal
  import pdb
  from apscheduler.schedulers.background import BackgroundScheduler
  from studio import fs_tracker, model
  from studio.util import logs
  from studio.queues.local_queue import LocalQueue
  from studio.util.gpu_util import get_available_gpus, get_gpu_mapping, get_gpus_summary
  from studio.artifacts.artifact import Artifact
  from studio.experiments.experiment import Experiment
  from studio.util.util import sixdecode, str2duration, retry, parse_verbosity, check_for_kb_interrupt
label_desc: Use image node_id 5 for calling a global function with example usage: worker_loop(queue, parsed_args, single_experiment, timeout, verbose) and returns: retval, experiment, retval