There is a part of python script as follows, these functions call C++ functions.

GenerateMesh()
CloseProject()

GenerateMesh start external QProcess to do real task, then return immediatly. It's async. There is another function reciving QProcess::finished signal to do some other work.
CloseProject closes the program.
This design has a fatal problem. GenerateMesh is async, CloseProject is invoked, at this point, the child process is not finished.
A possible solution is move all python operation to subthread, and make GeneratorMesh synchronous. but other function do a lot of UI operation.
Is there a proper way to block or pause python running?