面试题：在分布式系统，你能想出来几种生成唯一ID的方案？(15)_系统唯一ID是我们在设计一个系统的时候

return timestamp;

protected long timeGen()
{
return (long)(DateTime.UtcNow - new DateTime(1970 1 1 0 0 0 DateTimeKind.Utc)).TotalMilliseconds;

测试代码如下：

private static void TestIdWorker()
{
HashSet<long> set = new HashSet<long>();
IdWorker idWorker1 = new IdWorker(0 0);
IdWorker idWorker2 = new IdWorker(1 0);
Thread t1 = new Thread(() => DoTestIdWoker(idWorker1 set));
Thread t2 = new Thread(() => DoTestIdWoker(idWorker2 set));