随手写的. 可能有点问题

public Byte[] segmentSort(Byte[] bytes, int step, int threadNum) throws InterruptedException {
    final int len = bytes.length;
    Byte[] res = new Byte[len];
    final AtomicInteger cur = new AtomicInteger(0);
    CountDownLatch countDownLatch = new CountDownLatch(threadNum);
    IntStream.range(0, threadNum).forEach(i -> {
        final Thread thread = new Thread(() -> {
            int left = 0;
            int right = 0;
            while (left != len) {       //[left,right)
                do {
                    left = cur.get();
                    right = Math.min(left + step, len);
                } while (!cur.compareAndSet(left, right));
                if (left == right) break;
                Arrays.sort(bytes, left, right, ((o1, o2) -> o2 - o1));
                System.arraycopy(bytes, left, res, left, right - left);
            }
            countDownLatch.countDown();
        });
        thread.setName("segment_thread_" + i);
        thread.setDaemon(true);
        thread.start();
    });
    countDownLatch.await();
    return res;
}