当你在程序中使用多线程时，这经常会用到，而且这些线程需要同时访问同一个资源时，这个可能性很大，这时候你就需要用到线程同步技术。有些线程以只读方式访问资源，我们叫它ReadThread，而有些线程却需要对资源进行写入，我们叫它WriteThread，我们暂时先这样称呼。如果一个线程对资源的访问是读写方式，我们把它看作是WriteThread。

-when you process multiple threads, which are often used, but these threads need to visit the same resources, the great possibility that when you need to use thread synchronization technology. Some threads to read-only access to resources, we ask ReadThread, and some thread is the need for resources to write, we ask WriteThread the time being, we do call first. If a thread right of access to resources is reading and writing, we see it as WriteThread.