Dynamic conformance checking for object oriented design and code

This dissertation is a description of research that examines the feasibility of checking the conformance of dynamic properties with the runtime behaviour of object-oriented programs. We have developed a notation and an associated mechanism to do so. The notation consists of design documents based on the Unified Modelling Language (UML). The documents consist of sets of UML class and object diagrams. We have extended the syntax of the object diagrams to incorporate elements of the syntax of the deductive database language GraphLog. We refer to the resulting object diagrams as Visual Constraint Diagrams (VCD's). VCD's can express runtime properties that cannot be expressed graphically by standard UML object diagrams. These properties are constraints over instances of classes. They express exceptions, i.e., conditions that should not occur if the object-oriented program is correct. A good example of such an exception is that a linked list must not contain a loop. VCD's can be used to automate runtime checking of object-oriented programs. To facilitate the process, we have developed a checker tool written in Java based on the formal semantics of our notation. The tool accepts a core snapshot extracted by another party program and a set of VCD's as input. It produces a diagnostic report of exceptions as its output. We have conducted a case study of the performance of the tool based on an object-oriented simulation. Using the results of the study, we have categorized the constraints that are expressible using the VCD notation and have conducted some performance analysis of the tool. We hope our research will aid in the maintenance of accurate, up to date design documents during software development.