Quote Originally Posted by T_h_e_o View Post
how do you guarantee that the two signals of a are *both* emitted before the main thread is executed?
Signals are always emitted immediately. It is slots that can be executed later depending on thread affinity.

As for your question: I'm still in the process of thinking about different solutions, so no software available yet to easily put some test code into.
You can see a complete test case in my previous post, there is no need for any special software apart Qt itself.