protected void processReaderEvent() throws IOException {
    // There should be a reader event available, or coming soon, so okay to be blocking call.
    ReaderEvent event = getReaderEvent();
    switch (event.getEventType()) {
      case DONE:
        break;
      default:
        throw new IOException("Expected reader event with done status, but got "
            + event.getEventType() + " with message " + event.getMessage());
    }
  }
Base LLAP RecordReader to handle receiving of the data from the LLAP daemon.
llap-client/src/java/org/apache/hadoop/hive/llap/LlapBaseRecordReader.java