code: def _wait_for_lock(self, lock_file):
          
          sleeptime = .5
          first_message_flag = False
          dot_count = 0
          recover_file = self._recoverfile_from_lockfile(lock_file)
          while os.path.isfile(lock_file):
              if first_message_flag is False:
                  self.timestamp("Waiting for file lock: " + lock_file)
                  self._set_status_flag(WAIT_FLAG)
                  first_message_flag = True
              else:
                  sys.stdout.write(".")
                  dot_count = dot_count + 1
                  if dot_count % 60 == 0:
                      print("")  # linefeed
              # prevents the issue of pypier waiting for the lock file to be gone infinitely
              # in case the recovery flag is sticked by other pipeline when it's interrupted
              if os.path.isfile(recover_file):
                  sys.stdout.write(" Dynamic recovery flag found")
                  break
              time.sleep(sleeptime)
              sleeptime = min(sleeptime + 2.5, 60)
  
          if first_message_flag:
              self.timestamp("File unlocked.")
              self._set_status_flag(RUN_FLAG)
docs: Just sleep until the lock_file does not exist or a lock_file-related dynamic recovery flag is spotted
  
          :param str lock_file: Lock file to wait upon.