Slot priority in multithread

maratk1n

Hi all!

Small fragment of the project:

mainwindow.cpp

//constructor
    QThread *thread = new QThread;         
    //thread = new QThread(this);             
    valve = new Valve(7);                   
    pressureSensors = new PressureSensors;  
    valve->moveToThread(thread);
    pressureSensors->moveToThread(thread);
    connect(pressureSensors, SIGNAL(remoteSignal(bool)), this, SLOT(readPressureSensors(bool)));
    connect(valve, SIGNAL(remoteSignal(bool)), this, SLOT(updateStates(bool)));
    connect(this, SIGNAL(valveOpen(int)), valve, SLOT(open(int)));
    connect(this, SIGNAL(valveClose(int)), valve, SLOT(close(int)));
    connect(valve, SIGNAL(valveStatus(int,bool,bool)), this, SLOT(valveIndicate(int,bool,bool)));
    QTimer *sensorsReadTimer = new QTimer(this);    
    sensorsReadTimer->moveToThread(thread);
    connect(sensorsReadTimer, SIGNAL(timeout()), pressureSensors, SLOT(readSensors()));
    sensorsReadTimer->start(100);                   
    QTimer *valvesReadTimer = new QTimer(this);     
    valvesReadTimer->moveToThread(thread);
    connect(valvesReadTimer, SIGNAL(timeout()), valve, SLOT(getAllStates()));
    valvesReadTimer->start(100);                   
    thread->start();
//***//
void MainWindow::openValve(int id)
{
    valveButton[id]->setEnabled(false);
    //valve->open(id);
    emit valveOpen(id);
}

protocol.cpp

bool Valve::open(int id)
{
    QByteArray arr;
    arr.resize(7);
    arr[0] = 0xAB;
    arr[1] = 0x01;
    arr[2] = 0x02;
    arr[3] = 0x02;
    arr[4] = id + 1;
    arr[5] = 0xFF;
    arr[6] = 0x00 - arr[1] - arr[2] - arr[3] - arr[4] - arr[5];

    QByteArray response = ComPort::get().requestResponse(arr);
    if(response[0] == arr[0])
    {
        qDebug() << "клапан №: " << id << " открыт!";
        valveState[id] = true;
        emit valveStatus(id, 1, 1);
        return 1;
    }
    emit valveStatus(id, 1, 0);
    return 0;
}
bool Valve::getAllStates()
{
    QByteArray arr;
    arr.resize(5);
    arr[0] = 0xAB;
    arr[1] = 0x01;
    arr[2] = 0x00;
    arr[3] = 0x00;
    arr[4] = 0x00 - arr[1] - arr[2] - arr[3];

    QByteArray response = ComPort::get().requestResponse(arr);
    if(response[0] == arr[0])
    {
        QBitArray bitStates(16);   

        for (int i = 4; i<6; i++)   
            for (int b = 0; b<8; b++)
                bitStates.setBit((i-4)*8+b, response.at(i)&(1<<b));
        for (int i = 0; i < valveState.size(); i++)         
            valveState[i] = bitStates[i];
        for (uint i = 0; i < sizeof(fittingState); i++) 
            fittingState[i] = bitStates[i+8];
        emit remoteSignal(1);
        return 1;
    }
    emit remoteSignal(0);
    return 0;
}
//***//
QByteArray ComPort::requestResponse(const QByteArray &data)
{
    mutex->lock();
    QByteArray readBuf;
    qDebug() << "-------------------------";
    if(!serial->isOpen())
        open();
    int attempts = 1;
    while (attempts <= REQATTEMPTS) {      //3 попытки
        if (serial->isWritable())
        {
            serial->write(data);
            qDebug() << "Попытка № " << attempts;
            qDebug() << "Запрос: " << data.toHex();
            while (serial->waitForReadyRead(WAITFORREADY)) {
                readBuf += serial->readAll();
                if (crcCheck(readBuf) && data[2] == readBuf[2] ){  //если CRC и команда сошлись -- успех!
                    qDebug() << "Ответ: " << readBuf.toHex();

                    responseCount++;
                    qDebug() << "Кол-во запросов:  " << responseCount;
                    qDebug() << "Кол-во таймаутов: " << timeoutCount;
                    float percent = timeoutCount * 100;
                    percent = percent / responseCount;
                    qDebug() << "Процент косяков:  " << QString::number(percent, 'f', 3) << "%";

                    close();
                    mutex->unlock();
                    return readBuf;
                }
            }
            //qDebug() << readBuf.toHex();
            readBuf.clear();
            qDebug() << "Таймаут...";

            timeoutCount++;

            close();
            open();
            attempts++;
        }
        else
        {
            qDebug() << "Порт " << portName << " не пишется!";
            close();
            mutex->unlock();
            return 0;
        }

    }
    close();
    mutex->unlock();
    return 0;
}

If I do not put valve and pressureSensors in a separate thread, then everything works more or less normally.
But if I put them in a separate thread, the valve opening slot works very late (~ 10-20 seconds, as lucky). As I understand it, this is because the signal is emitted from the main thread, and the slot is in the other thread. Is it possible to build a queue?

Slot open from Valve class must have the highest priority

Thankful in advance for the help!

VRonin

Since you've given a parent to the timers they wouldn't be able to move them to another thread.

My suspect is that it's not a problem of the connection itself but of your blocking design of the serial read. Try connecting a slot or lambda to readyRead instead of using waitForReadyRead

maratk1n

@VRonin
Timers have nothing to do with it. I tried it differently. The poll of the valves unambiguously moves to a separate thread, as the graphical interface stops lagging.
I need to wait a certain amount of time to get a response on the port, otherwise continue the poll. The valve opening slot for some reason starts very late (check with qDebug())

VRonin

@maratk1n said in Slot priority in multithread:

I need to wait

Yes, my point is that you do not, you can use it asynchronously

@maratk1n said in Slot priority in multithread:

The valve opening slot for some reason starts very late

This is probably because the event loop in the receiver is busy

@maratk1n said in Slot priority in multithread:

Timers have nothing to do with it.

Agree, nevertheless they are not moved to the separate thread

maratk1n

Changed some code. This, it seems, helped to solve the problem.

...
    QTimer *sensorsReadTimer = new QTimer(this);    // <<<<<<<<<< Change to new QTimer();
    sensorsReadTimer->moveToThread(thread);
    connect(sensorsReadTimer, SIGNAL(timeout()), pressureSensors, SLOT(readSensors()));
    sensorsReadTimer->start(100);    // <<<<<<<<<< Start the timer before moving to the thread                   
    QTimer *valvesReadTimer = new QTimer(this);     // <<<<<<<<<< Change to new QTimer();    
    valvesReadTimer->moveToThread(thread);
    connect(valvesReadTimer, SIGNAL(timeout()), valve, SLOT(getAllStates()));
    valvesReadTimer->start(100);    // <<<<<<<<<< Start the timer before moving to the thread                   
    ...

@VRonin Thanks :)