10000个线程更新同一行数据

@Test
public void threadTestOrderBy() throws InterruptedException {

    final Long id=141284830240768L;
    int threadCount=1000;
    final CountDownLatch begin = new CountDownLatch(1);
    final CountDownLatch end = new CountDownLatch(threadCount);
    final int[] result={0,0};
    final Object lock = new Object();
    ExecutorService executorService = Executors.newFixedThreadPool(1000);

    for (int i = 0; i < threadCount; i++) {
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    begin.await();
                    baseSiteService.updateOrderBy(id);
                    synchronized(lock){
                        result[0]++;
                    }
                } catch (Exception ex) {
                    synchronized(lock) {
                        result[1]++;
                    }
                    ex.printStackTrace();
                }finally{
                    end.countDown();
                }
            }
        });
        executorService.submit(thread);
    }
    System.out.println("1000个线程开始");
    begin.countDown();
    end.await();
    System.out.println("1000个线程更新结束");
    System.out.println("成功"+result[0]+",失败"+result[1]);
    BaseSiteEntity byId = this.baseSiteService.getById(id);
    System.out.println(byId.getOrderBy());
}

@Override
@Transactional
public void updateOrderBy(Long id) {
   BaseSiteEntity byId = this.baseSiteDao.getById(id);
   if (byId.getOrderBy() >= 1) {
      this.baseSiteDao.updateOrderBy(id);
   } else {
      throw new BusinessException("没有库存");
   }
}

<update id="updateOrderBy">
        update t_base_site t set t.order_by=t.order_by-1 where t.site_id=#{id}
    </update>
</mapper>

update t_base_site t set t.order_by=1 where t.site_id='141284830240768';

　　条件后期不成立,但是已经开始排队更新,导致结果为-数