public LongAdder getSinglePutMessageTopicTimesTotal(String topic) {
        LongAdder rs = putMessageTopicTimesTotal.get(topic);
        if (null == rs) {
            rs = new LongAdder();
            LongAdder previous = putMessageTopicTimesTotal.putIfAbsent(topic, rs);
            if (previous != null) {
                rs = previous;
            }
        }
        return rs;
    }
@Test
    public void getSinglePutMessageTopicTimesTotal() throws Exception {
        final StoreStatsService storeStatsService = new StoreStatsService();
        int num = Runtime.getRuntime().availableProcessors() * 2;
        for (int j = 0; j < 100; j++) {
            final AtomicReference<LongAdder> reference = new AtomicReference<>(null);
            final CountDownLatch latch = new CountDownLatch(num);
            final CyclicBarrier barrier = new CyclicBarrier(num);
            for (int i = 0; i < num; i++) {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            barrier.await();
                            LongAdder longAdder = storeStatsService.getSinglePutMessageTopicTimesTotal("test");
                            if (reference.compareAndSet(null, longAdder)) {
                            } else if (reference.get() != longAdder) {
                                throw new RuntimeException("Reference should be same!");
                            }
                        } catch (InterruptedException | BrokenBarrierException e) {
                            e.printStackTrace();
                        } finally {
                            latch.countDown();
                        }
                    }
                }).start();
            }
            latch.await();
        }
    }