Unable to get subscriber event call backs

edit

Hi,

Following ros2 quality of service demo , I created an example publisher & subscriber nodes hopping to receive a event call back, when the publisher terminates (when pressing ctrl + c ). The code compiles and executes and the subscriber is able to receive the messages published by the publisher but unable to call event callbacks when the publisher dies (ctrl + c ). Here is the code snippet

Subsciber.hpp

class ExternalFTSubsciber {
 public:
  ExternalFTSubsciber();

 private:
  void handleExternalFTSensorSub(const geometry_msgs::msg::WrenchStamped::SharedPtr wrenchStamped,
                                 const rclcpp::MessageInfo& messageInfo);

  rclcpp::Subscription<geometry_msgs::msg::WrenchStamped>::SharedPtr externalFTSensorSub;
  rclcpp::SubscriptionOptions subscription_options_;
};

Subsciber.cpp

 ExternalFTSubsciber::ExternalFTSubsciber() {
  rclcpp::init(argc, argv);
  auto node = rclcpp::Node::make_shared("ft_talker");

// rclcpp::SubscriptionOptions subscription_options_;  defined in header file      
subscription_options_.event_callbacks.deadline_callback = 
        [](rclcpp::QOSDeadlineRequestedInfo& event) {
            printf("Deadline missed - total %d (delta %d)", event.total_count, event.total_count_change);
        };

  subscription_options_.event_callbacks.liveliness_callback = 
    [](rclcpp::QOSLivelinessChangedInfo& event) -> void {
        printf(
            "Liveliness changed - alive %d (delta %d),"
            " not alive %d (delta %d)",
            event.alive_count, event.alive_count_change, event.not_alive_count, event.not_alive_count_change);
  };
  std::chrono::milliseconds liveliness_lease_duration(1000);

  rclcpp::QoS qos_profile(10);
  qos_profile
    .liveliness(RMW_QOS_POLICY_LIVELINESS_AUTOMATIC)
    .liveliness_lease_duration(liveliness_lease_duration);

  externalFTSensorSub = node->createSubscription<geometry_msgs::msg::WrenchStamped>(
      "external_wrench", qos_profile, std::bind(&ExternalFTSubsciber::handleExternalFTSensorSub, this, _1, _2),
      subscription_options_);
}

Publisher.hpp

int main(int argc, char** argv) {
  // Force flush of the stdout buffer.
  setvbuf(stdout, NULL, _IONBF, BUFSIZ);

  // Initialize ROS
  rclcpp::init(argc, argv);
  auto node = rclcpp::Node::make_shared("ft_talker");

  std::chrono::milliseconds liveliness_lease_duration(1000);
  rclcpp::QoS qos_profile(10);
  qos_profile
    .liveliness(RMW_QOS_POLICY_LIVELINESS_AUTOMATIC)
     .liveliness_lease_duration(liveliness_lease_duration);

  auto publisher = node->create_publisher<geometry_msgs::msg::WrenchStamped>("/UR5763/external_wrench", qos_profile);

  // Publish
  rclcpp::WallRate loop_rate(2ms);
  while (rclcpp::ok()) {
    auto message = std::make_unique<geometry_msgs::msg::WrenchStamped>();
    // message->header.seq = 123;
    message->header.stamp = node->get_clock()->now();
    message->header.frame_id = "tool";
try {
      publisher->publish(std::move(message));
      rclcpp::spin_some(node);
    } catch (const rclcpp::exceptions::RCLError& e) {
      RCLCPP_ERROR(node->get_logger(), "unexpectedly failed with %s", e.what());
    }
    loop_rate.sleep();
  }

  rclcpp::shutdown();
  return 0;
}

Thank you