作者：华清远见嵌入式学院。《Linux设备驱动开发详解》（08&09年度畅销榜TOP50）第9章、Linux设备驱动中的异步通知与异步I/O。在设备驱动中使用异步通知可以使得对设备的访问可进行时，由驱动主动通知应用程序进行访问。这样，使用无阻塞I/O的应用程序无须轮询设备是否可访问，而阻塞访问也可以被类似“中断”的异步通知所取代。

9.1节讲解了异步通知的概念和作用，9.2节讲解了Linux异步通知的编程方法，9.3节讲解了增加异步通知的globalfifo驱动及其在用户空间的验证。-Author: HuaQing vision embedded institute. The Linux device driver development "(08 and 09 sep TOP50) annual list of best-selling chapter 9, Linux device driver of asynchronous notification and asynchronous I/O. In the device driver can make use of asynchronous notification of the equipment can be conducted, the visit to notify the application driven visit. So, use no block I/O application without access to the equipment is polling, and block access can be similar to "break" replaced the asynchronous notification.

Section 9.1 explained asynchronous notification of the concept and function, section 9.2 explained Linux asynchronous notification of the programming method, section 9.3 explained the increase of asynchronous notification globalfifo drive and in user space validation.