class TicketsSystem
{
    public static void main(String[] args)
    {
        SellThread st=new SellThread();
        new Thread(st).start();
        new Thread(st).start();
        new Thread(st).start();
        new Thread(st).start();
    }
}

class SellThread implements Runnable
{
    int tickets=100;
    public void run()
    {
        while(true)
        {
            if(tickets>0)
            {
                System.out.println(Thread.currentThread().getName()+" sell tickets:    "+tickets);
                tickets--;
            }
        }
    }
}
为什么结果不是按顺序的？

谢谢两位版主！