请问,怎么判断rpc call 是否掉线

这是我写的重连,请指教 <pre> <code class="language-go"> package main var bBClient *rpc.Client var conn net.Conn func GetInstance() *rpc.Client { if conn != nil { err := conn.SetReadDeadline(time.Now().Add(time.Second * 1)) if err != nil { log.Fatal("setread-----", err) bBClient = nil } } else { logs.Debug("conn2", conn) } if bBClient == nil { return instance() } return bBClient } func instance() *rpc.Client { conn, err := net.Dial("tcp", beego.AppConfig.String("BBRpc")) if err != nil { log.Fatal("dialing:", err) } return jsonrpc.NewClient(conn) } func init() { instance() } </code></pre>