code: def running_jobs(self, exit_on_error=True):
          
          with self.handling_exceptions():
              if self.using_jobs:
                  from concurrent.futures import ProcessPoolExecutor
                  try:
                      with ProcessPoolExecutor(self.jobs) as self.executor:
                          yield
                  finally:
                      self.executor = None
              else:
                  yield
          if exit_on_error:
              self.exit_on_error()
docs: Initialize multiprocessing.