Browsing by Author "Fisher II, Marc"

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    An Evaluation of Change-Based Coverage Criteria
    Fisher II, Marc; Wloka, Jan; Tip, Frank; Ryder, Barbara G.; Luchansky, Alexander (Department of Computer Science, Virginia Polytechnic Institute & State University, 2011-03-01)
    Various coverage criteria are commonly used to assess the quality of test suites, but achieving full coverage according to these criteria is often impossible or impractical. Our research starts from the popular assumption that a disproportionate number of faults is likely to reside in recently changed code. Based on this assumption, we propose several change-based coverage criteria that reflect to what extent changes with respect to a previous program version are exercised by a test suite. In a set of experiments on programs from the SIR repository, we found change-based criteria to reveal faults better than traditional criteria, and to enable the construction of much smaller test suites with similar fault detection effectiveness. We also report on a case study that shows that achieving (near) 100% coverage according to a change-based criterion is both feasible and useful.
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    Exploring the Impact of Context Sensitivity on Blended Analysis
    Fisher II, Marc; Dufour, Bruno; Basu, Shrutarshi; Ryder, Barbara G. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2010-04-01)
    This paper explores the use of context sensitivity both intra- and interprocedurally in a blended (static/dynamic) program analysis for performance diagnosis of framework-intensive Web-based applications. Empirical experiments with an existing blended analysis algorithm [9] compare combinations of (i) use of a context-insensitive call graph with a context-sensitive calling context tree, and (ii) use (or not) of context-sensitive code pruning within methods. These experiments demonstrate achievable gains in scalability and performance in terms of several metrics designed for blended escape analysis, and report results in terms of object instances created, to allow more realistic conclusions from the data than were possible previously.
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    Visualizing the Results of a Complex Hybrid Dynamic-Static Analysis
    Fisher II, Marc; Marrs, Luke; Ryder, Barbara G. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2010-06-01)
    Complex static or hybrid static-dynamic analyses produce large quantities of structured data. In the past, this data was generally intended for use by compilers or other software tools that used the produced information to transform the application being analyzed. However, it is becomingly increasingly common for the results of these analyses to be used directly by humans. For example, in our own prior work we have developed a hybrid dynamic-static escape analysis intended to help developers identify sources of object churn within large framework-base applications. In order to facilitate human use of complex analysis results, visualizations need to be developed that allow a user to browse these results and to identify the points of interest within these large data sets. In this paper we present Hi-C, a visualization tool for our hybrid escape analysis that has been implemented as an Eclipse plugin. We show how Hi-C can help developers identify sources of object churn in a large framework-based application and how we have used the tool to assist in understanding the results of a complex analysis.