5,016 research outputs found
UML-F: A Modeling Language for Object-Oriented Frameworks
The paper presents the essential features of a new member of the UML language
family that supports working with object-oriented frameworks. This UML
extension, called UML-F, allows the explicit representation of framework
variation points. The paper discusses some of the relevant aspects of UML-F,
which is based on standard UML extension mechanisms. A case study shows how it
can be used to assist framework development. A discussion of additional tools
for automating framework implementation and instantiation rounds out the paper.Comment: 22 pages, 10 figure
C++ Standard Template Library by template specialized containers
The C++ Standard Template Library is the flagship example for libraries based
on the generic programming paradigm. The usage of this library is intended to
minimize the number of classical C/C++ errors, but does not warrant bug-free
programs. Furthermore, many new kinds of errors may arise from the inaccurate
use of the generic programming paradigm, like dereferencing invalid iterators
or misunderstanding remove-like algorithms. In this paper we present some
typical scenarios that may cause runtime or portability problems. We emit
warnings and errors while these risky constructs are used. We also present a
general approach to emit "customized" warnings. We support the so-called
"believe-me marks" to disable warnings. We present another typical usage of our
technique, when classes become deprecated during the software lifecycle
Self-Modeling Based Diagnosis of Software-Defined Networks
Networks built using SDN (Software-Defined Networks) and NFV (Network
Functions Virtualization) approaches are expected to face several challenges
such as scalability, robustness and resiliency. In this paper, we propose a
self-modeling based diagnosis to enable resilient networks in the context of
SDN and NFV. We focus on solving two major problems: On the one hand, we lack
today of a model or template that describes the managed elements in the context
of SDN and NFV. On the other hand, the highly dynamic networks enabled by the
softwarisation require the generation at runtime of a diagnosis model from
which the root causes can be identified. In this paper, we propose finer
granular templates that do not only model network nodes but also their
sub-components for a more detailed diagnosis suitable in the SDN and NFV
context. In addition, we specify and validate a self-modeling based diagnosis
using Bayesian Networks. This approach differs from the state of the art in the
discovery of network and service dependencies at run-time and the building of
the diagnosis model of any SDN infrastructure using our templates
C++ Templates as Partial Evaluation
This paper explores the relationship between C++ templates and partial
evaluation. Templates were designed to support generic programming, but
unintentionally provided the ability to perform compile-time computations and
code generation. These features are completely accidental, and as a result
their syntax is awkward. By recasting these features in terms of partial
evaluation, a much simpler syntax can be achieved. C++ may be regarded as a
two-level language in which types are first-class values. Template
instantiation resembles an offline partial evaluator. This paper describes
preliminary work toward a single mechanism based on Partial Evaluation which
unifies generic programming, compile-time computation and code generation. The
language Catat is introduced to illustrate these ideas.Comment: 13 page
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Constructing secure service compositions with patterns
In service based applications, it is often necessary to construct compositions of services in order to provide required functionality in cases where this is not possible through the use of a single service. Whilst creating service compositions, it is necessary to ensure not only that the functionality required of the composition is achieved but also that certain security properties are preserved. In this paper, we describe an approach to constructing secure service compositions. Our approach is based on the use of composition patterns and rules that determine the security properties that should be preserved by the individual services that constitute a composition in order to ensure that security properties of the overall composition are also satisfied. Our approach extends a framework developed to support the runtime service discovery
Modeling, Simulation and Emulation of Intelligent Domotic Environments
Intelligent Domotic Environments are a promising approach, based on semantic models and commercially off-the-shelf domotic technologies, to realize new intelligent buildings, but such complexity requires innovative design methodologies and tools for ensuring correctness. Suitable simulation and emulation approaches and tools must be adopted to allow designers to experiment with their ideas and to incrementally verify designed policies in a scenario where the environment is partly emulated and partly composed of real devices. This paper describes a framework, which exploits UML2.0 state diagrams for automatic generation of device simulators from ontology-based descriptions of domotic environments. The DogSim simulator may simulate a complete building automation system in software, or may be integrated in the Dog Gateway, allowing partial simulation of virtual devices alongside with real devices. Experiments on a real home show that the approach is feasible and can easily address both simulation and emulation requirement
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