Production-quality Software Research Articles

Transactionalizing legacy code

The addition of transactional memory (TM) support to existing languages provides the opportunity to create new soft- ware from scratch using transactions, and also to simplify or extend legacy code by replacing existing synchronization with language-level transactions. In this paper, we describe our experiences transactionalizing the memcached application through the use of the GCC implementation of the Draft C++ TM Specification. We present experiences and recommendations that we hope will guide the effort to integrate TM into languages, and that may also contribute to the growing collective knowledge about how programmers can begin to exploit TM in existing production-quality software.

Transactionalizing legacy code

The addition of transactional memory (TM) support to existing languages provides the opportunity to create new soft- ware from scratch using transactions, and also to simplify or extend legacy code by replacing existing synchronization with language-level transactions. In this paper, we describe our experiences transactionalizing the memcached application through the use of the GCC implementation of the Draft C++ TM Specification. We present experiences and recommendations that we hope will guide the effort to integrate TM into languages, and that may also contribute to the growing collective knowledge about how programmers can begin to exploit TM in existing production-quality software.

A Sequential Linear Constraint Programming Algorithm for NLP

A new method for nonlinear programming (NLP) using sequential linear constraint programming (SLCP) is described. Linear constraint programming (LCP) subproblems are solved by a new code using a recently developed spectral gradient method for minimization. The method requires only first derivatives and avoids having to store and update approximate Hessian or reduced Hessian matrices. Globalization is provided by a trust region filter scheme. Open source production quality software is available. Results on a large selection of CUTEr test problems are presented and discussed and show that the method is reliable and reasonably efficient.

Pathway Tools version 13.0: integrated software for pathway/genome informatics and systems biology

Pathway Tools is a production-quality software environment for creating a type of model-organism database called a Pathway/Genome Database (PGDB). A PGDB such as EcoCyc integrates the evolving understanding of the genes, proteins, metabolic network and regulatory network of an organism. This article provides an overview of Pathway Tools capabilities. The software performs multiple computational inferences including prediction of metabolic pathways, prediction of metabolic pathway hole fillers and prediction of operons. It enables interactive editing of PGDBs by DB curators. It supports web publishing of PGDBs, and provides a large number of query and visualization tools. The software also supports comparative analyses of PGDBs, and provides several systems biology analyses of PGDBs including reachability analysis of metabolic networks, and interactive tracing of metabolites through a metabolic network. More than 800 PGDBs have been created using Pathway Tools by scientists around the world, many of which are curated DBs for important model organisms. Those PGDBs can be exchanged using a peer-to-peer DB sharing system called the PGDB Registry.

Measuring progress in Premo order-verification

Since verification of computational simulation codes requires significant resources, the ability to measure progress in verification is critical to assess whether resources are being applied appropriately. Additionally, potential users need to know what fraction of the software has been order-verified. In this study, the procedures and progress measures presented by Knupp et al. (Measuring progress order-verification within software development projects. Engineering with Computers, appears in this issue, 2007) are demonstrated on the Premo software, which simulates compressible aerodynamics through and around general geometries. Premo was selected for this demonstration because extensive order-verification tests have been previously performed, yet no systematic effort has been made to assess test-suite completeness or progress. This effort was performed to identify the practical issues encountered when attempting to apply the ideas by Knupp (Measuring progress order-verification within software development projects. Engineering with Computers, appears in this issue, 2007) to existing production-quality software. In this work, a non-specific order-verification exercise is considered, as opposed to an application-specific order-verification exercise, since past and present Premo order-verification efforts have been motivated by the need to verify all of the code, rather than portions relevant for specific applications. Constructing an order-verification test suite that verifies the order of accuracy of all the code capabilities is a major step in measuring progress. A practical approach to test-suite construction is described that helps create a complete test suite through a combination of coarse-grain code coverage, input-keyword inspection, discretization-algorithm documentation, and expert knowledge. Some of the difficulties and issues encountered during the construction of the test suite are described, along with recommendations on how to deal with them. Once the test suite is constructed, the progress measures proposed by Knupp (Measuring progress order-verification within software development projects. Engineering with Computers, appears in this issue, 2007) can be evaluated and used to reconstruct the history of progress in Premo verification over the past several years. Gaps in Premo verification are identified and indicate future directions for making progress. Additionally, a measure of Premo verification fitness is computed for selected applications commonly simulated in the aerospace industry. It is hoped that this demonstration will provide a practical example for other software-development groups in measuring their own verification progress.

Applying domain engineering using RAISE into a particular banking domain

Recently, several flavors of formal methods have been gaining industrial acceptance and production quality software tools have begun emerging. Domain Engineering (DE) has been introduced as one of outstanding ideas in software development. It serves Formal Methods (FMs) that provide a rigorous, mathematical based framework for specifying, defining, and verifying systems in the software development for critical systems. New software engineering includes three phases consisting of domain engineering, requirement engineering, and design and implementation. The purpose of this paper is to introduce the key concepts of domain engineering with providing overview information about formal methods and applying RAISE as a formal method that has been used successfully on various, diverse applications. Then, a particular banking domain is specified with using them. Formal model presented in this paper is provable to implement this domain. With merginging object oriented technology with domain engineering, this model can be extended for serving in distributed systems. It improves reusability and reliability in such environments.

Solving large-scale control problems

In this article we discuss sparse matrix algorithms and parallel algorithms, as well as their application to large-scale systems. For illustration, we solve the linear-quadratic regulator (LQR) problem and apply balanced truncation model reduction using either parallel computing or sparse matrix algorithms. We conclude that modern tools from numerical linear algebra, along with careful investigation and exploitation of the problem structure, can be used to derive algorithms capable of solving large control problems. Since these approaches are implemented in production-quality software, control engineers can employ complex models and use computational tools to analyse and design feedback control laws.

A constraint-based scheduler for batch manufacturing

Batch manufacturing poses unique challenges to schedulers. The manufacturing processes are unpredictable, the environment is dynamic, and the required task and resource models are complicated. The Honeywell batch scheduler uses constraint envelope scheduling to address these needs, offering support for both schedule modifications and rescheduling. The authors are reimplementing the scheduler as production quality software. They describe the process of building the scheduler and lessons learned during this process.

A study of software metrics

This article reports on an empirical study conducted to explore the interdependencies among a number of software metrics and validate a new metric. Also a model for code faults in terms of static metrics is presented and investigated. The software analyzed is a commercial data-base system currently being sold and used widely. Availability of various post-release versions of this production-quality software package, together with the corresponding history data, provide a new dimension for metrics analysis. The results of this study indicate that: 1. 1) all of the static metrics considered correlate well to each other and also to the size metric; 2. 2) the residual complexity metric was validated against other static metrics; 3. 3) none of the metrics under consideration was able to identify all of the variations in code faults; in fact, even a multiple-variable model accounted for only one quarter of the variance in the number of code faults; and 4. 4) the static metrics' intercorrelations are consistent across versions.

A parallel preconditioned conjugate gradient package for solving sparse linear systems on a Cray Y-MP

In this paper we discuss current activities at Cray Research to develop general-purpose, production-quality software for the efficient solution of sparse linear systems. In particular, we discuss our development of a package of iterative methods that includes conjugate gradient and related methods (GMRES, ORTHOMIN and others) along with several preconditioners (incomplete Cholesky and LU factorization and polynomial). Vector and parallel performance issues are discussed as well as package design. Also, benchmarks on a wide variety of real-life problems are presented to assess the robustness and performance of methods implemented in our software. For symmetric positive-definite problems, we also compare the performance of the preconditioned conjugate gradient code with our parallel implementation of the multifrontal method for sparse Cholesky factorization.

A hardware logic simulation system

Multiple-delay logic simulation algorithms developed for the microprogrammable accelerator for rapid simulations (MARS) hardware simulator are discussed. In particular, timing-analysis algorithms for event cancellations, spike and race analyses, and oscillation detection are described. It is shown how a reconfigurable set of processors, called processing elements (PEs), can be arranged in a pipelined configuration to implement these algorithms. The algorithms operate within the partitioned-memory, message-passing architecture of MARS. Three logic simulators-two multiple delay and one unit delay-have been implemented using slightly different configuration of the available PEs. In these simulators, VLSI chips are modeled at the gate level with accurate rise/fall delays assigned to each logic primitive. On-chip memory blocks are modeled functionally and are integrated into the simulation framework. The MARS hardware simulator has been tested on many VLSI chip designs and has demonstrated a speed improvement of about 50 times that of an Amdahl 5870 system running a production-quality software simulator while retaining the accuracy of simulations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

DSM: an object-relationship modeling language

The Data Structure Manager (DSM) combines object-oriented programming with semantic data modeling concepts in the context of the C language. DSM is a full-featured object-oriented language which includes single and multiple inheritance, class descriptor objects, metaclasses, choice of method binding time, error handling, persistent objects, modularity, and an interactive interpreter in an efficient manner. In addition, DSM supports the association and aggregation relationships as part of the Object Modeling Technique (OMT) used for conceptual design. DSM has been used since 1986 to build a variety of research and production-quality software such as an advanced CAF/CAD system.