You might want to do some research on multi threaded development. MQX call's them tasks, most other operating systems call them threads. There are some books you can buy on multithreaded application development which you should find useful. Many books are RToS specific, but the concepts are almost identical.
IMO, MQX is not about teaching us the techniques of multithreaded application development, its about supplying the RToS and the information related to MQX.
Good luck.