Timers cannot be ####### from another thread

[SPlatten]

@SGaist, @eyllanesc , do you mean:

void clsMsgSender::run() {    
    mpsckClient = new QTcpSocket(this);
    QObject::connect(mpsckClient, &QTcpSocket::connected
                    ,this, &clsMsgSender::onConnected);
    QObject::connect(mpsckClient, &QAbstractSocket::errorOccurred
                    ,this, &clsMsgSender::onErrorOccurred);
    QObject::connect(mpsckClient, &QTcpSocket::disconnected
                    ,this, &clsMsgSender::onDisconnected);
    //Default last state to connected as it won't be!
    QTcpSocket::SocketState sckCurState;
    while( mblnRun == true  ) {
...

[SGaist]

@SPlatten said in Timers cannot be ####### from another thread:

@eyllanesc , mpsckClient is created in the clsMsgSender constructor which is not in a thread.

Wrong, the object creation happens in the main thread.

You always have at least one thread when you execute an application.

[SPlatten]

@SGaist , then that is exactly how it was done already since the object clsMsgSender is created in the main thread.

[SGaist]

And that is the issue. You are thus creating your socket in the main thread as well.

[SPlatten]

@SGaist , sorry, I'm not sure why you say that, the class clsMsgSender is not a socket. If you mean that:

mpsckClient = new QTcpSocket(this);

Is that the problem? because this is in the clsMsgSender constructor, then please explain what I should do because I suggested moving it into the thread and the response was no.

Can you please clarify what I'm doing wrong and how to fix it?

[Christian Ehrlicher]

@SPlatten said in Timers cannot be ####### from another thread:

new QTcpSocket(this);

This creates an object with the parent in the main thread. And since a child must be in the same thread as the parent...
Don't pass this as parent and delete it by your own.

[SGaist]

@Christian-Ehrlicher for sockets you have to go one step further and ensure it's created in the thread that will actually use it.

[SPlatten]

Obviously I have a lot to learn where Qt threads are concerned, can someone point me to some relevant thread & socket tutorials or documentation?

I will take a closer look at fortuneserver and fortuneclient.

[SGaist]

Start with the QThread. There are several other chapters linked from the details of the class.

[SPlatten]

@SGaist , I've just read the details on QThread and I didn't see anything specifically regarding the use of Sockets. I then found this when searching online:

https://forum.qt.io/topic/57753/qtcpsocket-and-qthread
Obviously you are familiar with this one.

https://stackoverflow.com/questions/34641732/qtcpsocket-handling-in-another-qthread
Not sure what the conclusion of the above was...

https://www.bogotobogo.com/Qt/Qt5_QTcpServer_Multithreaded_Client_Server.php
Working through this....

I must say the approach the last link takes is exactly the way I started, with sub-classing my listening class from QTcpServer, however after several posts here advising not to do this I changed my class.