how can I create a signal to use from inside an rt_task?

spiderdab

I have a rt_task which runs on a xenomai kernel. I wanted to add a GUI, for it so I created a MainWindow project in qtcreator (qt5) and started playing with it.
The problem I have is that when something happens inside my rt_task, I have to change something in the GUI, and I know the correct way is to use signal/slot, but I don't know how to create or emit a signal from a rt_thread.
in the main.cpp the relevant part is this:

void ethercat_process_run(void *arg)
{
    RTIME now, previous=0;
    int32_t toff=0;
    RTIME rt_ts = rt_timer_read();

    while (run)
    {
...bla bla...
    }
}

int main(int argc, char *argv[])
{
...cut...
    rt_task_create(&ethercat_task, "ethercat_proccess_task", 0, 99, 0);
    rt_task_set_affinity(&ethercat_task, &cpu_set_ecat); 		//CPU affinity forEtherCAT task
    rt_task_start(&ethercat_task, &ethercat_process_run, NULL);
...cut...
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    return a.exec();
}

VRonin

Signals are public methods. Just create a QObject containing your signals and call those methods.

class rt_taskMessanger : public QObject{
Q_OBJECT
Q_DISABLE_COPY(rt_taskMessanger)
public:
explicit rt_taskMessanger(QObject* parent = nullptr) : QObject(parent){}
signals:
void somethingHappened();
};

rt_taskMessanger * rtMessanger;
int main(int argc, char *argv[])
{
rt_taskMessanger msg;
rtMessanger = &msg;
...cut...
    rt_task_create(&ethercat_task, "ethercat_proccess_task", 0, 99, 0);
    rt_task_set_affinity(&ethercat_task, &cpu_set_ecat); 		//CPU affinity forEtherCAT task
    rt_task_start(&ethercat_task, &ethercat_process_run, NULL);
...cut...
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
QObject::connect(rtMessanger,&rt_taskMessanger::somethingHappened,[](){qDebug("Something Happened");});
    return a.exec();
}

void ethercat_process_run(void *arg)
{
    RTIME now, previous=0;
    int32_t toff=0;
    RTIME rt_ts = rt_timer_read();

    while (run)
    {
...bla bla...
rtMessanger->somethingHappened();
    }
}

P.S.
make sure your while (run) doesn't block the main event loop otherwise you'll probably need to move that part to a new thread

spiderdab

@VRonin Thank you for your quick answer.
however I have an error on qDebug, saying: expected unqualified-id.
I added #include <QDebug>, but I can't find around what I'm missing..

VRonin

Does it matter? that's just placeholder code, don't waste your time on it. replace it with std::cout if need be

spiderdab

@VRonin The class you suggested works ok.
Thanks for your help.

Pablo J. Rogina

@spiderdab said in how can I create a signal to use from inside an rt_task?:

The class you suggested works ok.

great, so please don't forget to mark your post as solved!