code: def fiber_background(listen_addr, event_dict):
      global admin_host, admin_port
  
      # Background thread for handling inter fiber process admin traffic
      ip, port = listen_addr
      host = ""
  
      sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
      sock.bind((host, port))
      logger.debug(
          "fiber background thread attempt to bind %s:%s", host, port
      )
      # fix port number (could be 0 previously)
      _, port = sock.getsockname()
      logger.debug(
          "fiber background thread bind addr is to %s:%s", host, port
      )
      # backlog argument becomes optional since Python 3.5, but in order
      # to make Fiber work with 3.4, here we set a reasonable listen backlog
      # size. See https://docs.python.org/3.4/library/socket.html
      sock.listen(5)
  
      admin_host = ip
      admin_port = port
  
      sentinel = event_dict[-1]
      # notifi master thread that background thread is ready
      sentinel.set()
      logger.debug("fiber_background thread ready")
      while True:
          conn, addr = sock.accept()
          logger.debug("got connection from %s", addr)
          # fixed 4 byte id
          buf = conn.recv(4)
          # struct.unpack returns a tuple event if the result only has
          # one element
          ident = struct.unpack("<I", buf)[0]
          event = event_dict.get(ident, None)
          if event is None:
              logger.warn(
                  "something is wrong, no event found for this id: %s",
                  ident,
              )
              continue
          logger.debug("got connection for id %s", ident)
          event_dict[ident] = conn
          event.set()
  
imports: import fcntl
  import io
  import itertools
  import logging
  import multiprocessing
  import os
  import socket
  import struct
  import subprocess
  import sys
  import threading
  import time
  from multiprocessing import reduction, spawn, util
  from multiprocessing.context import set_spawning_popen
  import cloudpickle
  import requests
  import fiber.util
  import fiber.config
  from fiber.backend import get_backend
  from fiber.core import JobSpec
  from fiber.core import ProcessStatus
label_desc: Use image node_id 2 for calling a global function with example usage: fiber_background(listen_addr, event_dict) without return types