这是一个展示c++中volatile类型的很好的例子，里面同时嵌入了汇编语言，通过例子说明了volatile能够具有让编译器丧失优化功能，从而，程序能及时从内存中访问变量-This is a show c++ very good example of the type of volatile, which at the same time embedded in the assembly language examples illustrate the volatile loss of comp