说明：  My primary mission in this book is to offer a simple, lightweight alternative to a design automation tool by providing concrete, efficient, and proven implementations of statecharts that every practitioner reasonably proficient in C or C++ can start using within days. • The techniques needed to implement and use UML statecharts — the main constructive element in the UML specification (presented in Part I). • A real− time application framework — a complete software infrastructure for executing statecharts, tailored to embedded real− time systems and based on active objects and asynchronous event passing (presented in Part II).