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Abstract. We present a novel deadlock analysis for concurrent objects based on the results inferred by a points-to analysis and a may-happenin-parallel (MHP) analysis. Similarly to other analysis, we build a dependency graph such that the absence of cycles in the graph ensures deadlock freeness. An MHP analysis provides an over-approximation of the pairs of program points that may be running in parallel. The crux of the method is that the analysis integrates the MHP information within the dependency graph in order to discard unfeasible cycles that otherwise would lead to false positives. We argue that our analysis is more precise and/or efficient than previous proposals for deadlock analysis of concurrent objects. As regards accuracy, we are able to handle cases that other analyses have pointed out as challenges. As regards efficiency, the complexity of our deadlock analysis is polynomial.

Abstract. This paper presents a may-happen-in-parallel (MHP) analysis for OO languages based on concurrent objects. In this concurrency model, objects are the concurrency units such that, when a method is invoked on an object o2 from a task executing on object o1, statements of the current task in o1 may run in parallel with those of the (asynchronous) call on o2, and with those of transitively invoked methods. The goal of the MHP analysis is to identify pairs of statements in the program that may run in parallel in any execution. Our MHP analysis is formalized as a method-level (local ) analysis whose information can be modularly composed to obtain application-level (global ) information.

Abstract. We present the main concepts, usage and implementation of SACO, a static analyzer for concurrent objects. Interestingly, SACO is able to infer both liveness (namely termination and resource boundedness) and safety properties (namely deadlock freedom) of programs based on concurrent objects. The system integrates auxiliary analyses such as points-to and may-happen-in-parallel, which are essential for increasing the accuracy of the aforementioned more complex properties. SACO provides accurate information about the dependencies which may introduce deadlocks, loops whose termination is not guaranteed, and upper bounds on the resource consumption of methods.

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Abstract-We present jPET, a whitebox test-case generator (TCG) which can be used during software development of Java applications within the Eclipse environment. jPET builds on top of PET, a TCG which automatically obtains test-cases from the bytecode associated to a Java program. jPET performs reverse engineering of the test-cases obtained at the bytecode level by PET in order to yield this information to the user at the source code level. This allows understanding the information gathered at the lower level and using it to test source Java programs.

This article presents a may-happen-in-parallel (MHP) analysis for languages with actor-based concurrency . In this concurrency model, actors are the concurrency units such that, when a method is invoked on an actor a 2 from a task executing on actor a 1 , statements of the current task in a 1 may run in parallel with those of the (asynchronous) call on a 2 , and with those of transitively invoked methods. The goal of the MHP analysis is to identify pairs of statements in the program that may run in parallel in any execution. Our MHP analysis is formalized as a method-level ( local ) analysis whose information can be modularly composed to obtain application-level ( global ) information. The information yielded by the MHP analysis is essential to infer more complex properties of actor-based concurrent programs, for example, data race detection, deadlock freeness, termination, and resource consumption analyses can greatly benefit from the MHP relations to increase their accuracy. We report on MayPar, a prototypical implementation of an MHP static analyzer for a distributed asynchronous language.