关于webscoket开发的消息送达率

使用扩展:github.com/gorilla/websocket

对client的消息写与心跳如下:

func (c *Client) write() {
    pingTicker := time.NewTicker(pingPeriod)
    defer func() {
        pingTicker.Stop()
        Manager.Unregister <- c
        c.Socket.Close()
    }()
    for {
        select {
        case point, ok := <-c.send:
            if !ok {
                c.Socket.WriteMessage(websocket.CloseMessage, []byte{})
                fmt.Println("send err:", point)
                return
            }
            point.PushTime = time.Now().Unix()
            msg, _ := json.Marshal(point)
            fmt.Println(point.Content)
            writeMessage := c.Socket.WriteMessage(websocket.TextMessage, msg)
            if writeMessage != nil {
                offline(point)
            }
        case <-pingTicker.C:
            c.Socket.SetWriteDeadline(time.Now().Add(writeWait))
            err := c.Socket.WriteMessage(websocket.PingMessage, []byte("ping"))
            c.Socket.WriteMessage(websocket.TextMessage, []byte("ping"))
            if err != nil {
                fmt.Println("time out:", err)
                return
            }
        }
    }

}

正常情况下使用conn.send <- point投递消息,client都正确接收了(50ms/条 10000条) 但是客户端手动断网之后(异常离线),当pingTicker.C响应到client离线时,出现了消息丢失的情况即client最后一条消息与离线消息断层. 也就是client异常离线后c.Socket.WriteMessage(websocket.TextMessage, msg)正常发送了消息 err==nil无法触发offline方法. 求问:如何修改才能保障消息的不丢失?