@Override
      public void run() {
        long prev = mvcc.getReadPoint();
        while (!finished.get()) {
          long newPrev = mvcc.getReadPoint();
          if (newPrev < prev) {
            // serious problem.
            System.out.println("Reader got out of order, prev: " + prev + " next was: " + newPrev);
            readerFailed.set(true);
            // might as well give up
            failedAt.set(newPrev);
            return;
          }
        }
      }
This is a hammer test that verifies MultiVersionConcurrencyControl in a multiple writer single
reader scenario.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestMultiVersionConcurrencyControl.java