模拟顾客服务,具体有:代理服务,顾客数目,启动线程,计算顾客的等待时间,顾客数，并累计总的等待时间,释放一个顾客等.-Simulation of customer service, specifically are: agency services, the number of customers, start threads, calculating the customer' s waiting time, customer number, and a cumulative total