How do I use a QTcpSocket from a subclass of QThread?

andyP

I am reading from a Tcp socket in a separate thread:

class ReadFromTcpThread : public QThread {
	Q_OBJECT
public:
	ReadFromTcpThread(const std::string& tcpAddress, unsigned int port) : m_tcpAddress(tcpAddress), m_port(port) { };
	void run() override;
private slots:
	void connected();
	void errorOccurred(QAbstractSocket::SocketError e_socketError);
	void processPendingBytes();
private:
	std::string m_tcpAddress;
	unsigned int m_port;
	QTcpSocket* m_tcpSocket = nullptr;
	QByteArray m_data;
};

void ReadFromTcpThread::run() {
	m_tcpSocket = new QTcpSocket;
	m_tcpSocket->moveToThread(QThread::currentThread());
	m_tcpSocket->connectToHost(m_tcpAddress.c_str(), m_port);
	connect(m_tcpSocket, &QAbstractSocket::connected, this, &ReadFromTcpThread::connected);
	connect(m_tcpSocket, &QAbstractSocket::errorOccurred, this, &ReadFromTcpThread::errorOccurred);
	connect(m_tcpSocket, &QTcpSocket::readyRead, this, &ReadFromTcpThread::processPendingBytes);
	exec(); // run event loop
}

Is this correct code?
It seems to work. If I used the QThread as the parent of the socket I got an error. Since the socket is created inside the run method I do not need to moveToThread()?

Christian Ehrlicher

@andyP said in How do I use a QTcpSocket from a subclass of QThread?:

Is this correct code?

No since all your slot are executed in the main thread because your ReadFromTcpThread lives in the main thread.

don't use threads for QTcpSocket - it's not needed
if you use a thread, use the worker approach to make sure all your stuff is done in your created thread.