[서평]「Component Software」 - Beyond Object-Oriented Programming -

Gilles Fauconnier & Mark Turner, " The way we think: conceptual blending and the mind's hidden complexities"

The Semantic Conception of Truth and the Foundations of Semantics

Change introduces conflict into software ecosystems: breaking changes may ripple through the ecosystem and trigger rework for users of a package, but often developers can invest additional effort or accept opportunity costs to alleviate or delay downstream costs. We performed a multiple case study of three software ecosystems with different tooling and philosophies toward change, Eclipse, R/CRAN, and Node.js/npm, to understand how developers make decisions about change and change-related costs and what practices, tooling, and policies are used. We found that all three ecosystems differ substantially in their practices and expectations toward change and that those differences can be explained largely by different community values in each ecosystem. Our results illustrate that there is a large design space in how to build an ecosystem, its policies and its supporting infrastructure; and there is value in making community values and accepted tradeoffs explicit and transparent in order to resolve conflicts and negotiate change-related costs.

https://par.nsf.gov/servlets/purl/10038310

How to break an API: cost negotiation and community values in three software ecosystems

Maximum Satisfiability (MaxSAT) is an optimization version of SAT, and many real world applications can be naturally encoded as such. Solving MaxSAT is an important problem from both a theoretical and a practical point of view. In recent years, there has been considerable interest in developing efficient algorithms and several families of algorithms have been proposed. This paper overviews recent approaches to handle MaxSAT and presents a survey of MaxSAT algorithms based on iteratively calling a SAT solver which are particularly effective to solve problems arising in industrial settings. First, classic algorithms based on iteratively calling a SAT solver and updating a bound are overviewed. Such algorithms are referred to as iterative MaxSAT algorithms. Then, more sophisticated algorithms that additionally take advantage of unsatisfiable cores are described, which are referred to as core-guided MaxSAT algorithms. Core-guided MaxSAT algorithms use the information provided by unsatisfiable cores to relax clauses on demand and to create simpler constraints. Finally, a comprehensive empirical study on non-random benchmarks is conducted, including not only the surveyed algorithms, but also other state-of-the-art MaxSAT solvers. The results indicate that (i) core-guided MaxSAT algorithms in general abort in less instances than classic solvers based on iteratively calling a SAT solver and that (ii) core-guided MaxSAT algorithms are fairly competitive compared to other approaches.

/pdf/iterative-and-core-guided-maxsat-solving-a-survey-and-hl9eruxu7b.pdf

Iterative and core-guided MaxSAT solving: A survey and assessment

The widespread adoption of Free and Open Source Software (FOSS) in many strategic contexts of the information technology society has drawn the attention on the issues regarding how to handle the complexity of assembling and managing a huge number of (packaged) components in a consistent and effective way. FOSS distributions (and in particular GNU/Linux-based ones) have always provided tools for managing the tasks of installing, removing and upgrading the (packaged) components they were made of. While these tools provide a (not always effective) way to handle these tasks on the client side, there is still a lack of tools that could help the distribution editors to maintain, on the server side, large and high-quality distributions. In this paper we present our research whose main goal is to fill this gap: we show our approach, the tools we have developed and their application with experimental results. Our contribution provides an effective and automatic way to support distribution editors in handling those issues that were, until now, mostly addressed using ad-hoc tools and manual techniques.

/pdf/managing-the-complexity-of-large-free-and-open-source-2re96kg8gw.pdf

Managing the Complexity of Large Free and Open Source Package-Based Software Distributions

Component-based systems often describe context requirements in terms of explicit inter-component dependencies. Studying large instances of such systems?such as free and open source software (FOSS) distributions?in terms of declared dependencies between packages is appealing. It is however also misleading when the language to express dependencies is as expressive as boolean formulae, which is often the case. In such settings, a more appropriate notion of component dependency exists: strong dependency. This paper introduces such notion as a first step towards modeling semantic, rather then syntactic, inter-component relationships. Furthermore, a notion of component sensitivity is derived from strong dependencies, with ap- plications to quality assurance and to the evaluation of upgrade risks. An empirical study of strong dependencies and sensitivity is presented, in the context of one of the largest, freely available, component-based system.

Strong Dependencies between Software Components

Component-based systems often describe context requirements in terms of explicit inter-component dependencies. Studying large instances of such systems — such as free and open source software (FOSS) distributions — in terms of declared dependencies between packages is appealing. It is however also misleading when the language to express dependencies is as expressive as boolean formulae, which is often the case. In such settings, a more appropriate notion of component dependency exists: strong dependency. This paper introduces such notion as a first step towards modeling semantic, rather then syntactic, inter-component relationships. Furthermore, a notion of component sensitivity is derived from strong dependencies, with applications to quality assurance and to the evaluation of upgrade risks. An empirical study of strong dependencies and sensitivity is presented, in the context of one of the largest, freely available, component-based system.

/pdf/strong-dependencies-between-software-components-38saqg3ude.pdf

Strong dependencies between software components

We provide an overview of the FET-Open Project CerCo (‘Certified Complexity’). Our main achievement is the development of a technique for analysing non-functional properties of programs (time, space) at the source level with little or no loss of accuracy and a small trusted code base. The core component is a C compiler, verified in Matita, that produces an instrumented copy of the source code in addition to generating object code. This instrumentation exposes, and tracks precisely, the actual (non-asymptotic) computational cost of the input program at the source level. Untrusted invariant generators and trusted theorem provers may then be used to compute and certify the parametric execution time of the code.

/pdf/certified-complexity-cerco-2dumdzkfwr.pdf

Certified Complexity (CerCo)

Quantum Information Processing, which is an exciting area of research at the intersection of physics and computer science, has great potential for influencing the future development of information pro- cessing systems. The building of practical, general purpose Quantum Computers may be some years into the future. However, Quantum Communication and Quantum Cryptography are well developed. Commercial Quantum Key Distribution systems are easily available and several QKD networks have been built in various parts of the world. The security of the protocols used in these implementations rely on information-theoretic proofs, which may or may not reflect actual system behaviour. Moreover, testing of implementations cannot guarantee the absence of bugs and errors. This paper presents a novel framework for modelling and verifying quantum protocols and their implementations using the proof assistant Coq. We provide a Coq library for quantum bits (qubits), quantum gates, and quantum mea- surement. As a step towards verifying practical quantum communication and security protocols such as Quantum Key Distribution, we support multiple qubits, communication and entanglement. We illustrate these concepts by modelling the Quantum Teleportation Protocol, which communicates the state of an unknown quantum bit using only a classical channel.

/pdf/formalization-of-quantum-protocols-using-coq-2pri5gmz4x.pdf

Jaap Boender

Papers

Managing the Complexity of Large Free and Open Source Package-Based Software Distributions

Strong Dependencies between Software Components

Strong dependencies between software components

Certified Complexity (CerCo)

Formalization of quantum protocols using Coq