An analysis of test data selection criteria using the RELAY model of fault detection

RELAY is a model of faults and failures that defines failure conditions, which describe test data for which execution will guarantee that a fault originates erroneous behavior that also transfers through computations and information flow until a failure is revealed. This model of fault detection provides a framework within which other testing criteria's capabilities can be evaluated. In this paper, we analyze three test data selection criteria that attempt to detect faults in six fault classes. This analysis shows that none of these criteria is capable of guaranteeing detection for these fault classes and points out two major weaknesses of these criteria. The first weakness is that the criteria do not consider the potential unsatisfiability of their rules; each criterion includes rules that are sufficient to cause potential failures for some fault classes, yet when such rules are unsatisfiable, many faults may remain undetected. Their second weakness is failure to integrate their proposed rules; although a criterion may cause a subexpression to take on an erroneous value, there is no effort made to guarantee that the intermediate values cause observable, erroneous behavior. This paper shows how the RELAY model overcomes these weaknesses

Fault-based regression testing in a reactive environment

Regression testing is the process of retesting software after modification. Regression testing is a major factor contributing to the high cost of software maintenance. To control this cost, regression testing must be accomplished efficiently through effective reuse of test cases and judicious generation of new test cases.Fault-based testing focuses on the detection of particular classes of faults. RELAY is a fault-based testing technique that guarantees the detection of errors caused by any fault in a chosen fault classification. RELAY can be used as a regression testing technique to generate the test cases required to demonstrate that a modification is properly made. In addition, the information related to a test case chosen to detect a potential fault guides in choosing previously-selected test cases that should be reused, for a given modification.This paper presents the concepts behind RELAY and discusses how RELAY could be used as a regression testing technique. It also describes a testing environment that supports reactive regression testing as well as testing throughout the development lifecycle, which is based on integrating the RELAY model with other testing techniques

Producing Scheduling that Causes Concurrent Programs to Fail

A noise maker is a tool that seeds a concurrent program with conditional synchronization primitives (such as yield()) for the purpose of increasing the likelihood that a bug manifest itself. This work explores the theory and practice of choosing where in the program to induce such thread switches at runtime. We introduce a novel fault model that classifies locations as .good., .neutral., or .bad,. based on the effect of a thread switch at the location. Using the model we explore the terms in which efficient search for real-life concurrent bugs can be carried out. We accordingly justify the use of probabilistic algorithms for this search and gain a deeper insight of the work done so far on noise-making. We validate our approach by experimenting with a set of programs taken from publicly available multi-threaded benchmark. Our empirical evidence demonstrates that real-life behavior is similar to what our model predicts

Analyzing the test process using structural coverage

A large, commercially developed FORTRAN program was modified to produce structural coverage metrics. The modified program was executed on a set of functionally generated acceptance tests and a large sample of operational usage cases. The resulting structural coverage metrics are combined with fault and error data to evaluate structural coverage. It was shown that in the software environment the functionally generated tests seem to be a good approximation of operational use. The relative proportions of the exercised statement subclasses change as the structural coverage of the program increases. A method was also proposed for evaluating if two sets of input data exercise a program in a similar manner. Evidence was provided that implies that in this environment, faults revealed in a procedure are independent of the number of times the procedure is executed and that it may be reasonable to use procedure coverage in software models that use statement coverage. Finally, the evidence suggests that it may be possible to use structural coverage to aid in the management of the acceptance test processed