说明：  vxworks平台下，基于缓冲队列（单链表）的多任务网络通讯。从通讯入手---双缓冲网络通讯，另外，还有网络通断检测。
(VxWorks platform, based on the buffer queue (single list) multi-tasking network communications.--- Starting from the double buffer communications network communications, In addition, there are network-off detection.)