7.4 Specifications

In this section we take a look at some advanced techniques for specification and how they can be used.

7.4.1 Control-Oriented Specification Languages

SDL

We have already seen how to use state machines to specify control in UML. An example of a widely used state machine specification language is the SDL language[Roc82], which was developed by the communications industry for specifying communication protocols, telephone systems, and so forth. As illustrated in Figure 7.6, SDL specifications include states, actions, and both conditional and unconditional transitions between states. SDL is an event-oriented state machine model because transitions between states are caused by internal and external events.

Figure 7.6 The SDL ...

Get Computers as Components, 3rd Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.