Failure to call parameter service after server restarts

[sloretz]

Bug report

Required Info:

• Operating System:
  • Ubuntu 16.04, Windows 10
• Installation type:
  • source
• Version or commit hash:
  • vcs export --exact https://gist.github.com/sloretz/fa3f96d81cb1a7b479309fdf26566e14
• DDS implementation:
  • Fast-RTPS
• Client library (if applicable):
  • rclcpp, rclpy

Steps to reproduce issue

Build an rclcpp executable with the following code

#include <string>

#include "rclcpp/rclcpp.hpp"

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

  std::string node_name = "initial_params_node";
  std::string namespace_ = "/";
  auto node = rclcpp::Node::make_shared(node_name, namespace_);

  rclcpp::spin(node);

  rclcpp::shutdown();
  return 0;
}

Run the following python code (change the hardcoded path to initial_params_rclcpp to the above binary)

from rcl_interfaces.srv import GetParameters
import rclpy

import subprocess
import threading
import time


rclpy.init()
node = rclpy.create_node('tests_yaml')


def background_spin(node):
    while rclpy.ok():
        # workaround ros2/rclpy#188
        rclpy.spin_once(node, timeout_sec=time.sleep(0.25))


try:
    # Keep an executor running in the background
    thr = threading.Thread(target=background_spin, args=(node,), daemon=True)
    thr.start()

    while True:
        print('start loop')


        proc = subprocess.Popen(['/workspace/ros2-dev0/build/test_cli/initial_params_rclcpp', '__node:=listener'])
        # Using the listener node instead fixes the issue
        # proc = subprocess.Popen(['ros2', 'run', 'demo_nodes_cpp', 'listener'])
        try:
            # print('about to create client')
            client = node.create_client(GetParameters, '/listener/get_parameters')
            # print('about to wait for service')
            client.wait_for_service()

            # Sleeping here fixes the issue
            # time.sleep(1)

            # print('about to send service request')
            request = GetParameters.Request()
            request.names = ('use_sim_time',)
            client.call(request)

            # print('about to destroy client')
            node.destroy_client(client)
        finally:
            # print('about to kill subprocess')
            proc.kill()
finally:
    node.destroy_node()
    rclpy.shutdown()

Expected behavior

start loop would be printed forever

Actual behavior

start loop prints twice. The program is forever waiting in the second invocation of client.call(request)

Additional information

ros2/system_tests#274 (comment)

[sloretz]

Possibly related to ros2/rmw_fastrtps#205