grpc_handle_attr_get_np - Gets handle attributes.
  grpc_error_t grpc_handle_attr_get_np(grpc_handle_attr_t_np *attr,
                                grpc_handle_attr_name_t_np name,
                                void **value)
  grpc_handle_attr_t_np *attr  grpc_handle_attr_name_t_np name  void *valueThe grpc_handle_attr_get_np() function returns the values of handle attributes. See the manual of grpc_handle_attr_set_np() for details of grpc_handle_attr_name_t_np.
Memory area allocated for the attribute value should be released by calling grpc_handle_attr_release_np() after the value was referred.
This function is MT-safe.
If successful, GRPC_NO_ERROR is returned. In the case of an error, Error code is returned.
  GRPC_NOT_INITIALIZED  GRPC_OTHER_ERROR_CODE