[ros-users] ROS performance - strange behaviour?

[Peter Müller]

Hi,

sorry I guess I forgot the obvious things. I am talking about roscpp

Here is the code of the producer, called TestProducer:
void TestProducer::setup()
{
    std::vector<uint8_t> data(10 * 1024, 1);
    data_packet.payload = data;

    connected_receiver = 0;

    outStream = node.advertise<ros_perf::Blob> ("pTopic", 1024, boost::bind(
            &TestProducer::receiverConnected, this));
}

void TestProducer::execute()
{
    ros::Rate loop_rate(20);
    int current_iterations = 0;



    while (ros::ok() && 1 != connected_receiver) {
        ros::spinOnce();
        loop_rate.sleep();
    }


    // no callbacks, just sending out data
    while (ros::ok()) {
        if (current_iterations < 10000) {
            for(int i = 0;i < 2;++i) {
                utility::PTime::now(data_packet.timestamp);
                outStream.publish(data_packet);
            }
            ++current_iterations;
        }
        loop_rate.sleep();
    }
}


Here is the code of the receiver, called TestNode:
void TestNode::setup()
{
    sub = node.subscribe<ros_perf::Blob> ("pTopic", 1024, boost::bind(&TestNode::process, this, _1, 1));
}

void TestNode::execute()
{
    ros::spin();
}

void TestNode::process(const BlobConstPtr& msg, unsigned int index)
{
    double t_now = 0.0;
    utility::PTime::now(t_now);

    burst_times.push_back(msg.get()->timestamp);
    burst_times.push_back(t_now);
}

The Blob message looks like this:
float64 timestamp
uint8[] payload


The setup runs locally, so there is no problems with clockskew. PTime uses clock_gettime(CLOCK_REALTIME, timespec*) and should work correctly.