the program freezes

[serkan_tr]

hello, I am making a project with QT, in this project I am reading data from serial. When the device with serial in my project is disconnected, it performs a port scan again and connects to the device. but I want these parts to continue independently of the program by doing the reading and searching parts with threads. but even if I do port search and data reading part with thread, the program freezes while detecting the connection and reconnecting.
How can I make a better logic because of the signal and slot mechanism?

Serial::Serial(): voltage(0), cam_value(0), prev_byte(FOOTHER), state(0){
    port_ = new QSerialPort(this);
    connectionTimer = new QTimer(this);
    connectionTimer->setInterval(1000);
    connectionTimer->start();
    initializationData(RESET_ALL);
    checkDeviceConnection();
//    connect(port_, &QSerialPort::readyRead, this, &Serial::readBytes);
//    connect(connectionTimer, &QTimer::timeout, this, &Serial::isConnected);
    serial_thread = std::thread{std::bind(&Serial::spinSerial, this)};
}

Serial::~Serial(){
    port_->close();
    connectionTimer->stop();
    delete connectionTimer;
    delete port_;
}

void Serial::spinSerial(){
//    connect(port_, &QSerialPort::readyRead, this, &Serial::readBytes);
//    connect(connectionTimer, &QTimer::timeout, this, &Serial::isConnected);
}

void Serial::isConnected(){
    elapsed_time = std::chrono::steady_clock::now() - prev_time;
    if((elapsed_time.count()/1000000) > (time_coef * TIME_OUT)){
        checkDeviceConnection();
        isConnect = false;
        // qDebug() << "Disconnected From Device";
    }else{
        // qDebug() << "Connection Established";
    }
}

void Serial::checkDeviceConnection(){
    if(port_->isOpen()) {  port_->close();  }
    for(const QSerialPortInfo port_list : QSerialPortInfo::availablePorts()){
        if((port_list.manufacturer() == "FTDI") || (port_list.description() == "Arduino Mega 2560") ){
            prev_time = std::chrono::steady_clock::now();
            port_->setPortName(port_list.portName());
            port_->setBaudRate(BAUDRATE);
            port_->setDataBits(QSerialPort::Data8);
            while(port_->open(QIODevice::ReadWrite)){  
                qDebug() << "ReadWrite "; 
                isConnect = true; 
            }
            time_coef = 10;
        }
#ifdef DEBUG
        qDebug() << "-----------------------------------------------------";
        qDebug() << "portName:          " << port_list.portName();
        qDebug() << "systemLocation:    " << port_list.systemLocation();
        qDebug() << "description:       " << port_list.description();
        qDebug() << "manufacturer:      " << port_list.manufacturer();
        qDebug() << "serialNumber:      " << port_list.serialNumber();
        qDebug() << "vendorIdentifier:  " << port_list.vendorIdentifier();
        qDebug() << "productIdentifier: " << port_list.productIdentifier();
#endif
    }
}

void Serial::readBytes(){
    while(port_->bytesAvailable()){
        uint8_t cur_byte;
        port_->read((char*)&cur_byte, 1);
        if(state == 0){
            if((cur_byte == HEADER) && (prev_byte == FOOTHER)){ rx_buffer[state++] = cur_byte; }
            else { state = 0; }
        }else if( state < HEADER_LEN + PAYLOAD_LEN){
            rx_buffer[state++] = cur_byte;
        }else if(state < HEADER_LEN + FOOTHER_LEN + PAYLOAD_LEN){
            state = 0;
            prev_byte = cur_byte;
            if(cur_byte == FOOTHER){
                raw_data[0] = (static_cast<int16_t>(rx_buffer[1] & 0x01));
                raw_data[1] = (static_cast<int16_t>((rx_buffer[1]>>1) & 0x01));
                raw_data[2] = (static_cast<int16_t>((rx_buffer[1]>>2) & 0x01));
                raw_data[3] = (static_cast<int16_t>((rx_buffer[1]>>3) & 0x01));
                raw_data[4] = (static_cast<int16_t>((rx_buffer[1] >> 4) | ((rx_buffer[2] << 4) & 0x03FF)));
                raw_data[5] = (static_cast<int16_t>((rx_buffer[2] >> 6) | ((rx_buffer[3] << 2) & 0x03FF)));
                raw_data[6] = (static_cast<int16_t>((rx_buffer[4])      | ((rx_buffer[5] << 8) & 0x03FF)));
                raw_data[7] = (static_cast<int16_t>((rx_buffer[5] >> 2) | ((rx_buffer[6] << 6) & 0x03FF)));
                raw_data[8] = (static_cast<int16_t>((rx_buffer[6] >> 4) | ((rx_buffer[7] << 4) & 0x03FF)));
                raw_data[9] = (static_cast<int16_t>((rx_buffer[7] >> 6) | ((rx_buffer[8] << 2) & 0x03FF)));
                time_coef = 1;
                if(debug_serial){
                    qDebug() << raw_data[0] << raw_data[1] << raw_data[2] <<
                        raw_data[3] << raw_data[4];
                    qDebug() << raw_data[5] << raw_data[6] << raw_data[7] <<
                        raw_data[8] << raw_data[9];
                    qDebug() << "------------------";
                }
            }else{ state = 0;  }
        }else    { state = 0;  }
        prev_byte = cur_byte;
        prev_time = std::chrono::steady_clock::now();
    }
}

void Serial::writeBytes(uint8_t new_data){
    // qDebug() << new_data;
    if ( !(port_->isOpen())) { return ;}
    if(new_data == tx_data[1]) { return ;}
    tx_data[1] = new_data;
    port_->write((char*)(tx_data), 5);
    port_->flush();
}

[Christian Ehrlicher]

@serkan_tr said in the program freezes:

eading and searching parts with threads. but even if I do port search and data reading part with thread, the program freezes while detecting the connection and reconnecting.

Why? What do you gain from this except headaches?

[serkan_tr]

@Christian-Ehrlicher I may have expressed myself wrong. My purpose is that the data coming from the serial port does not affect the program.

[Christian Ehrlicher]

@serkan_tr said in the program freezes:

My purpose is that the data coming from the serial port does not affect the program.

It does not since QSerialPort is (like nearly all other I/O classes in Qt) asynchronous.