I want to add a new node handle in init.cpp, to do some caculations on tcp packages which uses this ros_comm

edit

I added this class

class Rosperf {
 public:
  ros::NodeHandle node_;
  ros::Subscriber sub_;
//  ros::Publisher pub_;

  Rosperf() {
    init();
  }

  void init() {
    sub_ = node_.subscribe("/perfswitcher", 1, &Rosperf::rosperfCallback, this);
    std::cout << "sub to /perfswitcher" << std::endl;

//    pub_ = node_.advertise<std_msgs::Bool>("/perfswitcher", 5);
//    std::cout << "pub to /perfswitcher" << std::endl;
  }

  void rosperfCallback(const std_msgs::Bool::ConstPtr& switch_on) {
    std::cout << "received switcher command" << std::endl;
    if (switch_on) {

    } else {

    }
  }
};

to init.cpp, and instanciate it at the end of init() (after the g_initilize becomes true). The node works well with a node handle publishing to /perfswitch, but the rosperfCallback had never been call by spin() function of the node.

How can I make it work?