button 驱动，在应用层监控底层button driver 的动作时一般是开一个线程或进程，采用轮询的模式，这样很容易导致cpu占用时间达80 以上，严重拖累系统速度；为解决这种缺点，我们应该在底层button驱动中加入非阻塞模式的访问控制，如附件方法。-button-driven, application-layer control in the bottom button driver when the action is usually to open a thread or process, using polling mode, it can easily lead to 80　cpu occupancy over time, serious drag on system speed　To address this shortcoming, We should drive in the bottom button to add non-blocking mode of access control, such as the attachment method.