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Incrementalization across object abstraction

acm sigplan NOTICES 2005年第10期40卷 473-486页

作者： Liu, YA Stoller, SD Gorbovitski, M Rothamel, T Liu, YE SUNY Stony Brook Dept Comp Sci Stony Brook NY 11794 USA Univ Manitoba Dept Comp Sci Winnipeg MB R3T 2N2 Canada

Object abstraction supports the separation of what operations are provided by systems and components from how the operations are implemented, and is essential in enabling the construction of complex systems from components. Unfortunately, clear and modular implementations have poor performance when expensive query operations are repeated, while efficient implementations that incrementally maintain these query results are much more difficult to develop and to understand, because the code blows up significantly, and is no longer clear or modular. This paper describes a powerful and systematic method that first allows the "what" of each component to be specified in a clear and modular fashion and implemented straightforwardly in an object-oriented language;then analyzes the queries and updates, across object abstraction, in the straightforward implementation: and finally derives the sophisticated and efficient "how;, of each component by incrementally maintaining the results of repeated expensive queries with respect to updates to their parameters. Our implementation and experimental results for example applications in query optimization, role-based access control, etc. demonstrate tire effectiveness and benefit of the method.

关键词： design languages performance abstraction design program transformation incrementalization invariants program analysis program optimization object-oriented

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Pattern matching for design concept localization

Pattern matching for design concept localization

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2nd Working conference on Reverse Engineering

作者： KONTOGIANNIS, K DEMORI, R BERNSTEIN, M GALLER, M MERLO, E MCGILL UNIV SCH COMP SCIMONTREALPQ H3A 2A7CANADA

ISBN: (纸本)0818671114

The effective synergy of a number of different techniques is the key to the successful development of an efficient Reverse Engineering environment. Compiler technology, pattern matching techniques, visualization tools, and software repositories play an important role for the identification of procedural, data, and abstract-data-type related concepts in the source code. This paper describes a number of techniques used for the development of a distributed reverse engineering environment. design recovery is investigated through code-to-code and abstract-descriptions-to-code pattern matching techniques used to locate code that may implement a particular plan or algorithm. The code-to-code matching uses dynamic programming techniques to locate similar code fragments and is targeted for large software systems (1M LOC). Patterns are specified either as source code or as a sequence of abstract statements written in an concept language developed for this purpose. Markov models are used to compute similarity measures between an abstract description and a code fragment in terms of the probability that a given abstract statement can generate a given code fragment. The abstract-description-to-code matcher is under implementation and early experiments show it is a promising technique.

关键词： Software engineering

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Piranha: Reducing Feature Flag Debt at Uber 42

Piranha: Reducing Feature Flag Debt at Uber

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42nd acm/IEEE International conference on Software Engineering - Companion proceedings (ICSE-Companion) / 42nd acm/IEEE International conference on Software Engineering - Software Engineering in Practice (ICSE-SEIP)

作者： Ramanathan, Murali Krishna Clapp, Lazaro Barik, Rajkishore Sridharan, Manu Uber Technol Inc New York NY 10001 USA Univ Calif Riverside Riverside CA 92521 USA

ISBN: (纸本)9781450371230

Feature flags are commonly used in mobile app development and can introduce technical debt related to deleting their usage from the codebase. This can adversely affect the overall reliability of the apps and increase their maintenance complexity. Reducing this debt without imposing additional overheads on the developers necessitates the design of novel tools and automated workflows. In this paper, we describe the design and implementation of PIRANHA, an automated code refactoring tool which is used to automatically generate differential revisions (a.k.a diffs) to delete code corresponding to stale feature flags. PIRANHA takes as input the name of the flag, expected treatment behavior, and the name of the flag's author. It analyzes the ASTs of the program to generate appropriate refactorings which are packaged into a diff. The diff is assigned to the author of the flag for further processing, who can land it after performing any additional refactorings. We have implemented PIRANHA to delete code in Objective-C, Java, and Swift programs, and deployed it to handle stale flags in multiple Uber apps. We present our experiences with the deployment of PIRANHA from Dec 2017 to May 2019, including the following highlights: (a) generated code cleanup diffs for 1381 flags (17% of total flags), (b) 65% of the diffs landed without any changes, (c) over 85% of the generated diffs compile and pass tests successfully, (d) around 80% of the diffs affect more than one file, (e) developers process more than 88% of the generated diffs, (f) 75% of the generated diffs are processed within a week, and (g) PIRANHA diffs have been interacted with by similar to 200 developers across Uber. Piranha is available as open source at https://***/uber/piranha.

关键词： C (programming language)

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APL comparison tolerance 76

APL comparison tolerance

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8th International conference on APL, APL 1976

作者： Lathwell, R.H. IBM APL Design Philadelphia United States

ISBN: (纸本)9781450374163

An important aspect of the original implementation of APL\360 was the treatment of arithmetic functions as abstract functions defined on the continuous set of real numbers [1,2]. This had various consequences, including automatic conversion between different machine representations of numbers so that storage and other aspects of System/360 architecture could be used efficiently while suppressing its details. [2]“Fuzzy” comparisons were introduced so that the actual discrete, fixed-precision, hexadecimal representation could be partly disguisedThe technique used in the original implementation was to regard numbers whose difference was zero in the first twelve (of fourteen) hexadecimal digits to be equal. The definitions in [3] were developed by M. A. Jenkins and R. H. Lathwell in 1968 when it was found that, for some values, implications of relational functions such as B> A←→~ B≤ A were violated. It was later discovered that these definitions did not completely correct the difficulty, and when APL system variables were introduced [4], the tolerant functions were rederived, resulting in the definitions given here.

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design of a model-generated repository as a service for USDL 10

Design of a model-generated repository as a service for USDL

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proceedings of the 12th International conference on Information Integration and Web-based Applications & Services

作者： Duddy, Keith Henderson, Michael Metke-Jimenez, Alejandro Steel, Jim Queensland University of Technology 2 George St Brisbane QLD 4000 Australia

ISBN: (纸本)9781450304214

SAP and its research partners have been developing a language for describing details of Services from various viewpoints called the Unified Service Description language (USDL [12]. At the time of writing, version 3.0 describes technical implementation aspects of services, as well as stakeholders, pricing, lifecycle, and availability. Work is also underway to address other business and legal aspects of services. This language is designed to be used in service portfolio management, with a repository of service descriptions being available to various stakeholders in an organisation to allow for service prioritisation, development, deployment and lifecycle management. The structure of the USDL metadata is specified using an object-oriented metamodel that conforms to UML, MOF and EMF Ecore. As such it is amenable to code generation for implementations of repositories that store service description instances. Although Web services toolkits can be used to make these programming language objects available as a set of Web services, the practicalities of writing distributed clients against over one hundred class definitions, containing several hundred attributes, will make for very large WSDL interfaces and highly inefficient "chatty" implementations. This paper gives the high-level design for a completely model-generated repository for any version of USDL (or any other data-only metamodel), which uses the Eclipse Modelling Framework's Java code generation, along with several open source plugins to create a robust, transactional repository running in a Java application with a relational datastore. However, the repository exposes a generated WSDL interface at a coarse granularity, suitable for distributed client code and user-interface creation. It uses heuristics to drive code generation to bridge between the Web service and EMF granularities. Copyright 2010 acm.

关键词： Web services

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Multi-core parallelization in clojure - A case study

Multi-core parallelization in clojure - A case study

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6th European Lisp Workshop: European conference on Object-Oriented programming, ELW'09

作者： Kraus, Johann M. Kestler, Hans A. Institute of Neural Information Processing University of Ulm 9069 Ulm Germany Department of Internal Medicine I University Hospital Ulm 89081 Ulm Germany

ISBN: (纸本)9781605585390

In recent years, the demand for computational power in data mining applications has increased due to rapidly growing data sets. As a consequence, standard algorithms need to be parallelized for fast processing of the generated data sets. Unfortunately, most approaches for parallelizing algorithms require a careful software design and a deep knowledge about thread-safe programming. As a consequence they are hardly applicable for rapid prototyping of new algorithms. We outline the process of multi-core parallelization using Clojure, a new functional programming language utilizing the Java Virtual Machine (JVM) that does not require knowledge of thread-safe programming. We provide some benchmark results for our multi-core algorithm to demonstrate its computational power. The rationale behind Clojure is combining the industry-standard JVM with functional programming, immutable data structures, and a built-in concurrency support via software transactional memory. This makes it a suitable tool for parallelization and rapid prototyping in many areas. In this case study we present a multi-core parallel implementation of the k-means cluster algorithm. The multi-core algorithm shows an increase in computation speed up to a factor of 10 compared to R or network based parallelization. Copyright 2009 acm.

关键词： Parallel programming

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Implicit Invocation Meets Safe, Implicit Concurrency

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acm sigplan NOTICES 2011年第2期46卷 63-72页

作者： Long, Yuheng Mooney, Sean L. Sondag, Tyler Rajan, Hridesh Iowa State Univ Dept Comp Sci Ames IA 50011 USA

Writing correct and efficient concurrent programs still remains a challenge. Explicit concurrency is difficult, error prone, and creates code which is hard to maintain and debug. This type of concurrency also treats modular program design and concurrency as separate goals, where modularity often suffers. To solve these problems, we are designing a new language that we call Panini. In this paper, we focus on Panini's asynchronous, typed events which reconcile the modularity goal promoted by the implicit invocation design style with the concurrency goal of exposing potential concurrency between the execution of subjects and observers. Since modularity is improved and concurrency is implicit in Panini, programs are easier to reason about and maintain. The language incorporates a static analysis to determine potential conflicts between handlers and a dynamic analysis which uses the conflict information to determine a safe order for handler invocation. This mechanism avoids races and deadlocks entirely, yielding programs with a guaranteed deterministic semantics. To evaluate our language design and implementation we show several examples of its usage as well as an empirical study of program performance. We found that not only is developing and understanding Panini programs significantly easier compared to standard concurrent object-oriented programs, but also performance of Panini programs is comparable to their equivalent hand-tuned versions written using Java's fork-join framework.

关键词： languages design Performance Safe Implicit Concurrency Modularity

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design Automation for Quantum Architectures 20

Design Automation for Quantum Architectures

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20th conference and Exhibition on design, Automation and Test in Europe (DATE)

作者： Roetteler, Martin Svore, Krysta M. Wecker, Dave Wiebe, Nathan Microsoft Res Redmond WA 98052 USA

ISBN: (纸本)9783981537093

We survey recent strides made towards building a software framework that is capable of compiling quantum algorithms from a high-level description down to physical gates that can be implemented on a fault-tolerant quantum computer. We discuss why compilation and design automation tools such as the ones in our framework are key for tackling the grand challenge of building a scalable quantum computer. We then describe specialized libraries that have been developed using the LIQUi|> programming language. This includes reversible circuits for arithmetic as well as new, truly quantum approaches that rely on quantum computer architectures that allow the probabilistic execution of gates, a model that can reduce time and space overheads in some cases. We highlight why these libraries are useful for the implementation of many quantum algorithms. Finally, we survey the tool REVS that facilitate resource efficient compilation of higher-level irreversible programs into lower-level reversible circuits while trying to optimize the memory footprint of the resulting reversible networks. This is motivated by the limited availability of qubits for the foreseeable future.

关键词： Quantum computing Logic gates Computer architecture Computers Libraries Software algorithms Hardware

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CIAHelper: Towards Change Impact Analysis in Delta-Oriented Software Product Lines 18

CIAHelper: Towards Change Impact Analysis in Delta-Oriented ...

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22nd International Systems and Software Product Line conference (SPLC)

作者： Hamza, Mostafa Walker, Robert J. Elaasar, Maged Univ Calgary Dept Comp Sci Calgary AB Canada Carleton Univ Dept Syst & Comp Engn Ottawa ON Canada

ISBN: (纸本)9781450364645

Change is inevitable for software systems to deal with the evolving environment surrounding them, and applying changes requires careful design and implementation not to break existing functionalities. Evolution in software product lines (SPLs) is more complex compared to evolution for individual products: a change applied to a single feature might affect all the products in the whole product family. In this paper we present an approach for change impact analysis in delta-oriented programming (DOP), an existing language aimed at supporting SPLs. We propose the CIAHelper tool to identify dependencies within a DOP program, by analyzing the semantics of both the code artifacts and variability models to construct a directed dependency graph. We also consider how the source code history could be used to enhance the recall of detecting the affected artifacts given a change proposal. We evaluate our approach by means of five case studies on two different DOP SPLs.

关键词： Change impact analysis feature model variability model code assets delta-oriented programming

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The design and implementation of the control and integration software of a flexible manufacturing system

The design and implementation of the control and integration...

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proceedings of the First International conference on Systems Integration - ICSI '90

作者： Hadj-Alouane, Nejib Ben Chaar, Jarir K. Naylor, Arch W. Dept of Elec Eng & Comput Sci Univ of Michigan Ann Arbor MI USA

ISBN: (纸本)0818690275

The concepts of a methodology for designing and implementing the control and integration software of computer-integrated manufacturing systems are presented. The goal of this methodology is to build flexible and reusable software. Software flexibility is obtained by decoupling the process plan models from the factory floor model and by designing generic control algorithms. Reusability is achieved by building self-contained software/hardware components with general, possibility parametrized, interfaces. These reusable components can be used to populate manufacturing software libraries. Off-the-shelf components can then be assembled into manufacturing systems. Moreover, the interplay between simulated and actual hardware internals of software/hardware components is used as the basis of a testing strategy that performs offline simulation followed by incremental online testing. The application of the methodology to the design and implementation of the control and integration software of a prismatic machining cell is reported. A highly efficient implementation of this software has been carried out in the Ada programming language and is fully operational.

关键词： Flexible Manufacturing Systems

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