protected boolean hasInput() throws IOException {
    din.mark(1);
    if (din.read() >= 0) {
      din.reset();
      return true;
    }
    return false;
  }
Define success/error events which are passed to the reader from a different thread.
The reader will check for these events on end of input and interruption of the reader thread.
llap-client/src/java/org/apache/hadoop/hive/llap/LlapBaseRecordReader.java