Active objects in TCOZ

Active objects have their own thread of control and passive objects are controlled by others. In Object-Z, all objects are modelled as passive objects. Timed Communicating Object Z (TCOZ) extends the Object-Z notation with Timed CSP's process and timing constructs. The blending of the concepts of object and non-terminating process leads to the notion of active object in TCOZ. This paper considers the concept of active object, its role and implications in formal real-time object-oriented specification.