code: def meantsubpool(d, data_read):
      
  
      logger.info('Subtracting mean visibility in time...')
      data_read = numpyview(data_read_mem, 'complex64', datashape(d))
      tsubpart = partial(rtlib.meantsub, data_read)
  
      blranges = [(d['nbl'] * t/d['nthread'], d['nbl']*(t+1)/d['nthread']) for t in range(d['nthread'])]
      with closing(mp.Pool(1, initializer=initreadonly, initargs=(data_read_mem,))) as tsubpool:
          tsubpool.map(tsubpart, blr)
docs: Wrapper for mean visibility subtraction in time.
      Doesn't work when called from pipeline using multiprocessing pool.