Runtime observable and adaptable UML state machines: [email protected] approach

n embedded system is a self-contained system that incorporateselements of control logic and real-world interaction. UML State Ma-chines constitute a powerful formalism to model the behaviour ofthese types of systems. In current industrial environments, the soft-ware of these embedded systems have to cope with the increasingcomplexity and robustness requirements at runtime. One way tomanage these requirements is having the software component’sbehaviour model available at runtime ([email protected]). Thus,it is possible to enhance the safety of the software component byenabling verification and adaptation at runtime. In this paper, wepresent a model-driven approach to generate software components(namely, RESCO framework), which are able both to provide theirinternal information in model terms at runtime and adapt their be-haviour automatically when an error or an unexpected situation isdetected. The aforementioned runtime introspection and adaptationabilities are added automatically to the software component and itdoes not require the developer make any extra effort. The solutionhas been tested in the design and implementation of an industrialBurner controller. Results indicate that the software components ge-nerated by the presented solution provides introspection at runtime.Thanks to this introspection ability at runtime, the software com-ponents are able to adapt automatically from their normal-modebehaviour to a safe-mode behaviour which was defined to be usedin erroneous or unexpected situations at runtime. Therefore, it ispossible to enhance the safety of the systems consisting of thesesoftware components

Automatic Software Repair: a Bibliography

This article presents a survey on automatic software repair. Automatic software repair consists of automatically finding a solution to software bugs without human intervention. This article considers all kinds of repairs. First, it discusses behavioral repair where test suites, contracts, models, and crashing inputs are taken as oracle. Second, it discusses state repair, also known as runtime repair or runtime recovery, with techniques such as checkpoint and restart, reconfiguration, and invariant restoration. The uniqueness of this article is that it spans the research communities that contribute to this body of knowledge: software engineering, dependability, operating systems, programming languages, and security. It provides a novel and structured overview of the diversity of bug oracles and repair operators used in the literature

Neutral Networks of Real-World Programs and their Application to Automated Software Evolution

The existing software development ecosystem is the product of evolutionary forces, and consequently real-world software is amenable to improvement through automated evolutionary techniques. This dissertation presents empirical evidence that software is inherently robust to small randomized program transformations, or \u27mutations. Simple and general mutation operations are demonstrated that can be applied to software source code, compiled assembler code, or directly to binary executables. These mutations often generate variants of working programs that differ significantly from the original, yet remain fully functional. Applying successive mutations to the same software program uncovers large \u27neutral networks\u27 of fully functional variants of real-world software projects. These properties of \u27mutational robustness\u27 and the corresponding \u27neutral networks\u27 have been studied extensively in biology and are believed to be related to the capacity for unsupervised evolution and adaptation. As in biological systems, mutational robustness and neutral networks in software systems enable automated evolution. The dissertation presents several applications that leverage software neutral networks to automate common software development and maintenance tasks. Neutral networks are explored to generate diverse implementations of software for improving runtime security and for proactively repairing latent bugs. Next, a technique is introduced for automatically repairing bugs in the assembler and executables compiled from off-the-shelf software. As demonstration, a proprietary executable is manipulated to patch security vulnerabilities without access to source code or any aid from the software vendor. Finally, software neutral networks are leveraged to optimize complex nonfunctional runtime properties. This optimization technique is used to reduce the energy consumption of the popular PARSEC benchmark applications by 20% as compared to the best available public domain compiler optimizations. The applications presented herein apply evolutionary computation techniques to existing software using common software engineering tools. By enabling evolutionary techniques within the existing software development toolchain, this work is more likely to be of practical benefit to the developers and maintainers of real-world software systems

Metamorphic Runtime Checking of Non-Testable Programs

Challenges arise in assuring the quality of applications that do not have test oracles, i.e., for which it is impossible to know what the correct output should be for arbitrary input. Metamorphic testing has been shown to be a simple yet effective technique in addressing the quality assurance of these "non-testable programs". In metamorphic testing, if test input x produces output f(x), specified "metamorphic properties" are used to create a transformation function t, which can be applied to the input to produce t(x); this transformation then allows the output f(t(x)) to be predicted based on the already-known value of f(x). If the output is not as expected, then a defect must exist. Previously we investigated the effectiveness of testing based on metamorphic properties of the entire application. Here, we improve upon that work by presenting a new technique called Metamorphic Runtime Checking, a testing approach that automatically conducts metamorphic testing of individual functions during the program's execution. We also describe an implementation framework called Columbus, and discuss the results of empirical studies that demonstrate that checking the metamorphic properties of individual functions increases the effectiveness of the approach in detecting defects, with minimal performance impact

Automatic Detection of Defects in Applications without Test Oracles

In application domains that do not have a test oracle, such as machine learning and scientific computing, quality assurance is a challenge because it is difficult or impossible to know in advance what the correct output should be for general input. Previously, metamorphic testing has been shown to be a simple yet effective technique in detecting defects, even without an oracle. In metamorphic testing, the application's ``metamorphic properties'' are used to modify existing test case input to produce new test cases in such a manner that, when given the new input, the new output can easily be computed based on the original output. If the new output is not as expected, then a defect must exist. In practice, however, metamorphic testing can be a manually intensive technique for all but the simplest cases. The transformation of input data can be laborious for large data sets, and errors can occur in comparing the outputs when they are very complex. In this paper, we present a tool called Amsterdam that automates metamorphic testing by allowing the tester to easily set up and conduct metamorphic tests with little manual intervention, merely by specifying the properties to check, configuring the framework, and running the software. Additionally, we describe an approach called Heuristic Metamorphic Testing, which addresses issues related to false positives and non-determinism, and we present the results of new empirical studies that demonstrate the effectiveness of metamorphic testing techniques at detecting defects in real-world programs without test oracles

Using Metamorphic Testing at Runtime to Detect Defects in Applications without Test Oracles

First, we will present an approach called Automated Metamorphic System Testing. This will involve automating system-level metamorphic testing by treating the application as a black box and checking that the metamorphic properties of the entire application hold after execution. This will allow for metamorphic testing to be conducted in the production environment without affecting the user, and will not require the tester to have access to the source code. The tests do not require an oracle upon their creation; rather, the metamorphic properties act as built-in test oracles. We will also introduce an implementation framework called Amsterdam. Second, we will present a new type of testing called Metamorphic Runtime Checking. This involves the execution of metamorphic tests from within the application, i.e., the application launches its own tests, within its current context. The tests execute within the application's current state, and in particular check a function's metamorphic properties. We will also present a system called Columbus that supports the execution of the Metamorphic Runtime Checking from within the context of the running application. Like Amsterdam, it will conduct the tests with acceptable performance overhead, and will ensure that the execution of the tests does not affect the state of the original application process from the users' perspective; however, the implementation of Columbus will be more challenging in that it will require more sophisticated mechanisms for conducting the tests without pre-empting the rest of the application, and for comparing the results which may conceivably be in different processes or environments. Third, we will describe a set of metamorphic testing guidelines that can be followed to assist in the formulation and specification of metamorphic properties that can be used with the above approaches. These will categorize the different types of properties exhibited by many applications in the domain of machine learning and data mining in particular (as a result of the types of applications we will investigate), but we will demonstrate that they are also generalizable to other domains as well. This set of guidelines will also correlate to the different types of defects that we expect the approaches will be able to find