Experiments in Constrained Expression Analysis

• Authors: George S. Avrunin
• Venue: Experiments in Constrained Expression Analysis
• Year: 1988

THIS REPORT DESCRIBEDS SOME EXPERIMENTS IN ANALYZING CONCURRENT SOFTWARE SYSTEMS USING THE CONSTRAINED EXPRESSION FORMALISM [1,6]. THE PRIMARY ANALYSIS TECHNIQUES USED ARE THE INEQUALITY-BASED METHODS OF [1] AND [2], AND THE MAJOR GOAL OF THESE EXPERIMENTS IS THE IDENTIFICATION OF USEFUL HEURISTICS FOR GENERATING THE NECESSARY SYSTEMS OF INEQUALITIES. IN PARTI- CULAR, WE ARE INTERESTED IN DETERMINING THE EXTENT TO WHICH THIS PROCESS CAN BE AUTOMATED. A COUPLE OF WARNINGS TO THE READER ARE IN ORDER. FIRST, THIS REPORT IS A DESCRIPTION OF THE ACTUAL ANALYSIS OF SOME DISTRIBUTED SYSTEMS, AND NOT AN OUTLINE OF HOW SUCH AN ANALYSIS MIGHT BE MOST EFFICIENTLY OR ELEGANTLY CONDUCTED. WE LEARNED MANY THINGS ABOUT OUR METHODS DURING THESE EXPERI- MENTS, AND THIS IS REFLECTED IN CHANGES IN THEIR APPLICATION AS THE ANALY- SIS PROGRESSED. SECOND, WE ASSUME THAT THE READER HAS SOME FAMILIARITY WITH THE CONSTRAINED EXPRESSION FORMALISM AND THE DESIGN LANGUAGE `CEDL''. THE MATERIAL IN [1] AND [3] IS PROBABLY SUFFICIENT BACKGROUND FOR THE READER WHO IS FAMILIAR WITH ADA AND WILLING TO STRUGGLE A BIT WITH THE CONSTRAINED EXPRESSION FORMALISM. FOR FULLER DESCRIPTIONS OF CONSTRAINED EXPRESSIONS AND `CEDL'', THE READER SHOULD ALSO CONSULT [6] AND [4]. THE SYSTEMS ANALYZED IN THIS REPORT ARE BASED ON THE AUTOMATED GAS STA- TION EXAMPLES GIVEN BY HELMBOLD AND LUCKHAM IN [7] TO ILLUSTRATE THEIR RUN-