In this chapter, you discovered how a QThread class works and learned how to efficiently use tools provided by Qt to create a powerful multithreaded application. Your Mandelbrot application is able to use all the cores of your CPU to compute a picture quickly.
Creating a multithreaded application presents a lot of pitfalls (such as deadlock, event-loop flood, orphan threads, and overhead). The application architecture is important. If you are able to isolate the heavy code that you want to parallelize, everything should go well. Nevertheless, the user experience is of the utmost importance; you will sometimes have to accept a little overhead if your application gives the user a smoother feeling.
In the next chapter, we will see several ways to implement an Inter-Process Communication (IPC) between applications. The project example will enhance your current Mandelbrot application...