example.cpp

#include <iostream>
#include "rclcpp/rclcpp.hpp"
#include <memory>

using rclcpp::parameter_client::AsyncParametersClient;

rclcpp::node::Node::SharedPtr node;

void spin()
{
    // rclcpp::WallRate loop_rate(30);
    // while (rclcpp::ok()) {

    //     rclcpp::spin_some(node);
    //     loop_rate.sleep();
    // }
    rclcpp::spin(node);
}

int main(int argc, char **argv) {
    rclcpp::init(argc, argv);

    node = rclcpp::node::Node::make_shared("parameter_server_test");

    std::thread spinThread(&spin);
    // Extra scope so the first client will be deleted afterwards
    {
        std::cout << "Creating first client" << std::endl;
        auto parameters_client = std::make_shared<AsyncParametersClient>(node, "ParameterServer");
        auto results = parameters_client->set_parameters({
            rclcpp::parameter::ParameterVariant("DemoRobot", 2),
            rclcpp::parameter::ParameterVariant("bar", "hello"),
            rclcpp::parameter::ParameterVariant("baz", 1.45),
            rclcpp::parameter::ParameterVariant("foobar", true),
        });
        // Wait for the results.
        if (results.wait_for(5_s) != std::future_status::ready)
        {
            printf("set_parameters service call failed. Exiting example.\n");
            return -1;
        }
    }
    std::cout << "Creating second client" << std::endl;
    auto parameters_client_2 = std::make_shared<AsyncParametersClient>(node, "ParameterServer");
    // Get a few of the parameters just set.
    auto parameters = parameters_client_2->get_parameters({"DemoRobot", "baz"});
    // Here comes the segfault
    if (parameters.wait_for(5_s) != std::future_status::ready)
    {
        printf("get_parameters service call failed. Exiting example.\n");
        return -1;
    }
    for (auto & parameter : parameters.get()) {
        std::cout << "Parameter name: " << parameter.get_name() << std::endl;
        std::cout << "Parameter value (" << parameter.get_type_name() << "): " <<
                     parameter.value_to_string() << std::endl;
    }

    std::string input = "";

    while (input != "exit")
    {
        std::getline (std::cin,input);
        // Simply wait
    }

    // Must join a thread you start, it will end when !rclcpp::ok().
    spinThread.join();

    return 0;

}