Aspect-Oriented Programming for Test Control

Distributed and multithreaded systems are usually much more complex to analyze or test due to the nondeterminism involved. A possible approach to testing nondeterministic systems is to direct the execution of the program under test to take a certain path for each test, so that a unique output can be observed. Considering specification-based testing, we assume that a test case is given together with a test constraint for directing the internal nondeterministic choices. To instruct the program under test to execute according to a given test constraint, the program under test needs to communicate with the tester. In this thesis, we propose to use the features in Aspect-Oriented Programs to realize such communication. This solution does not require the availability of the source code of the program under test. We provide an automated translation from a test constraint to a set of aspects using AspectJ

Benchmark and Framework for Encouraging Research on Multi-Threaded Testing Tools

A problem that has been getting prominence in testing is that of looking for intermittent bugs. Multi-threaded code is becoming very common, mostly on the server side. As there is no silver bullet solution, research focuses on a variety of partial solutions. In this paper (invited by PADTAD 2003) we outline a proposed project to facilitate research. The project goals are as follows. The first goal is to create a benchmark that can be used to evaluate different solutions. The benchmark, apart from containing programs with documented bugs, will include other artifacts, such as traces, that are useful for evaluating some of the technologies. The second goal is to create a set of tools with open API s that can be used to check ideas without building a large system. For example an instrumentor will be available, that could be used to test temporal noise making heuristics. The third goal is to create a focus for the research in this area around which a community of people who try to solve similar problems with different techniques, could congregate

Towards efficient verification of systems with dynamic process creation

Modelling and analysis of dynamic multi-threaded state systems often encounters obstacles when one wants to use automated verification methods, such as model checking. Our aim in this paper is to develop a technical device for coping with one such obstacle, namely that caused by dynamic process creation. We first introduce a general class of coloured Petri nets-not tied to any particular syntax or approach-allowing one to capture systems with dynamic (and concurrent) process creation as well as capable of manipulating data. Following this, we introduce the central notion of our method which is a marking equivalence that can be efficiently computed and then used, for instance, to aggregate markings in a reachability graph. In some situations, such an aggregation may produce a finite representation of an infinite state system which still allows one to establish the relevant behavioural properties. We show feasibility of the method on an example and provide initial experimental results

A model checking-based approach for security policy verification of mobile systems

International audienceThis article describes an approach for the automated verification of mobile systems. Mobile systems are characterized by the explicit notion of (e.g., sites where they run) and the ability to execute at different locations, yielding a number of security issues. To this aim, we formalize mobile systems as Labeled Kripke Structures, encapsulating the notion of that describes the hierarchical nesting of the threads constituting the system. Then, we formalize a generic that includes rules for expressing and manipulating the code location. In contrast to many other approaches, our technique supports both access control and information flow specification. We developed a prototype framework for model checking of mobile systems. It works directly on the program code (in contrast to most traditional process-algebraic approaches that can model only limited details of mobile systems) and uses abstraction-refinement techniques, based also on location abstractions, to manage the program state space. We experimented with a number of mobile code benchmarks by verifying various security policies. The experimental results demonstrate the validity of the proposed mobile system modeling and policy specification formalisms and highlight the advantages of the model checking-based approach, which combines the validation of security properties with other checks, such as the validation of buffer overflows

Symbolic Model Checking of Concurrent Programs Using Partial Orders and On-the-Fly Transactions

Abstract. The state explosion problem is one of the core bottlenecks in the model checking of concurrent software. We show how to ameliorate the problem by combining the ability of partial order techniques to reduce the state space of the concurrent program with the power of symbolic model checking to explore large state spaces. Our new verification methodology involves translating the given concurrent program into a circuit-based model which gives us the flexibility to then employ any model checking technique of choice – either SAT or BDD-based – for verifying a broad range of linear time properties, not just safety. The reduction in the explored state-space is obtained by statically augmenting the symbolic encoding of the program by additional constraints. These constraints restrict the scheduler to choose from a minimal conditional stubborn set of transitions at each state. Another key contribution of the paper, is a new method for detecting transactions on-the-fly which takes into account patterns of lock acquisition and yields better reductions than existing methods which rely on a lockset based analysis. Moreover unlike existing techniques, identifying on-the-fly transactions does not require the program to follow a lock discipline in accessing shared variables. We have applied our techniques to the Daisy test bench and shown the existence of several bugs.

FOAL 2002 Proceedings: Foundations of Aspect-Oriented Langauges Workshop at AOSD 2002

Aspect-oriented programming is a new area in software engineering and programming languages that promises better support for separation of concerns. The first Foundations of Aspect-Oriented Languages (FOAL) workshop was held at the 1st International Conference on Aspect-Oriented Software Development in Enschede, The Netherlands, on April 22, 2002. This workshop was designed to be a forum for research in formal foundations of aspect-oriented programming languages. The call for papers announced the areas of interest for FOAL as including, but not limited to: formal semantics, formal specification, verification, theory of testing, aspect management, theory of aspect composition, and aspect translation and rewriting. The call for papers welcomed all theoretical and foundational studies of this topic. The goals of this FOAL workshop were to: • Explore the formal foundations of aspect-oriented programming. • Exchange ideas about semantics and formal methods for aspect-oriented programming languages. • Foster interest in the programming language theory communities concerning aspects and aspect- oriented programming languages. • Foster interest in the formal methods community concerning aspects and aspect-oriented programming. In addition, we hoped that the workshop would produce an outline of collaborative research topics and a list of areas for further exploration. The papers at the workshop, which are included in the proceedings, were selected from papers submitted by researchers worldwide. Due to time limitations at the workshop, not all of the submitted papers were selected for presentation

Program Model Checking: A Practitioner's Guide

Program model checking is a verification technology that uses state-space exploration to evaluate large numbers of potential program executions. Program model checking provides improved coverage over testing by systematically evaluating all possible test inputs and all possible interleavings of threads in a multithreaded system. Model-checking algorithms use several classes of optimizations to reduce the time and memory requirements for analysis, as well as heuristics for meaningful analysis of partial areas of the state space Our goal in this guidebook is to assemble, distill, and demonstrate emerging best practices for applying program model checking. We offer it as a starting point and introduction for those who want to apply model checking to software verification and validation. The guidebook will not discuss any specific tool in great detail, but we provide references for specific tools

Model-Checking Multi-Threaded Distributed Java Programs

Systematic state-space exploration is a powerful technique for verification of concurrent software systems. Most work in this area deals with manually-constructed models of those systems. We propose a framework for applying state-space exploration to multi-threaded distributed systems written in standard programming languages. It generalizes Godefroid's work on VeriSoft, which does not handle multi-threaded systems, and Bruening's work on ExitBlockRW, which does not handle distributed (multi-process) systems. Unlike ExitBlockRW, our search algorithms incorporate powerful partial-order methods, guarantee detection of deadlocks, and guarantee detection of violations of the locking discipline used to avoid race conditions in accesses to shared variables