Monitor Style Specification

The Monitor

The monitor observes the outputs of all agents sharing the interface and decides whether any protocol rules have been broken so far. If the correct output is true, the corresponding rule has not been broken so far; if it is false, the rule has been broken some time in the past. Essentially, the monitor checks for a collection of rules.

The Specification

• Contradictions
• Expected Behavior

Usage

• Create an environment

  When testing an implementation which uses the interfaces, one must somehow constrain the inputs to the implementation. This is because the implementation is not required to behave correctly when the inputs to it are random. Thus, a lot of work is usually required to create a correct environment for the implementation. This work can be avoided with a specification monitor! The specification monitor can be used to observe the inputs to the implementation and signal inputs which are "incorrect" by the interface protocol definition. So, only when the signal inputs are "correct" according to the monitor should the behavior of the implementation be checked.

  There is no need to create an implementation of the environment with a monitor style specification!

• Simulation Observer

  When testing two or more machines using the interface, the monitor can be added to the simulation environment and correctly pick the erring machine when an interface protocol rule is broken.