QT3 -- How does a gui communicate with a worker thread?

I have a simple gui that creates and then launches a thread (derived from QThread). The thread does some continuous processing and remains for the life of the gui. In order for the thread to communicate with the gui, I use postevent -- which, as I understand, is the correct way for a thread to communicate with the gui.

However, I am not sure how to safely communicate from the gui to the thread. Right now, I am directly accessing member functions/variables of my derived thread class (since the gui created/launched it). This method isn't safe, right?

What is the "official" way for the gui to communicate with a thread? (Note: I am stuck using QT3)

Thank You!