launch background process with POCO

Question

I am working with ROS and trying to integrate Poco Process for processes management in a ROS QT Interface.

Here's an example of what my node looks like so far :

void My_Interface::gazebo_launch_world()
{
    std::string command = "roslaunch";
    std::vector<std::string> args;
    args.push_back("robot_gazebo");
    args.push_back("robot_gazebo.launch");
    PocoProcess pp(command, args);
    pp.run();
}

int PocoProcess::run()
{
    int rc;
    try
    {
        Poco::Pipe outPipe;
        Poco::ProcessHandle ph = Poco::Process::launch(command_, args_, 0, &outPipe, 0);
        rc = ph.id();
        Poco::PipeInputStream istr(outPipe);
        Poco::StreamCopier::copyStream(istr, std::cout);
    }
    catch (Poco::SystemException& exc)
    {
        std::cout << exc.displayText() << std::endl;
        return (-1);
    }
    return rc;
}

This works fine (launching the process) but, the problem is that my interface freezes while waiting for the process to finish, which is really undesirable.

So, is there anyway that I can launch a POCO Process in the background ?

PS: (Hopelessly) I tried even the "&" on the args vector but it didn't work !

Thanks,

Answer 1

Ok, the solution was to detach the pipes from the output, as it blocks waiting to display it, I changed my code for the following (just commenting the pipes) and it worked.

void My_Interface::gazebo_launch_world()
{
    std::string command = "roslaunch";
    std::vector<std::string> args;
    args.push_back("robot_gazebo");
    args.push_back("robot_gazebo.launch");
    PocoProcess pp(command, args);
    pp.run();
}

int PocoProcess::run()
{
    int rc;
    try
    {
        Poco::ProcessHandle ph = Poco::Process::launch(command_, args_);
        rc = ph.id();
    }
    catch (Poco::SystemException& exc)
    {
        std::cout << exc.displayText() << std::endl;
        return (-1);
    }
    return rc;
}

Hope this will help someone else !