Software assessment using metrics: A comparison across large C++ and Java systems

This paper presents an assessment method to evaluate the quality of object oriented software systems. The assessment method is based on source code abstraction, object–oriented metrics and graphical representation. The metrics used and the underlying model representing the software are presented. The assessment method experiment is part of an industrial research effort with the Bell Canada Quality Engineering and Research Group. It helps evaluators assess the quality and risks associated with software by identifying code fragments presenting unusual characteristics. The assessment method evaluates object–oriented software systems at three levels of granularity: system level, class level and method level. One large C++ and eight Java software systems, for a total of over one million lines of code, are presented as case studies. A critical analysis of the results is presented comparing the systems and the two languages. This revised version was published online in June 2006 with corrections to the Cover Date.     

A comparative evaluation of generic programming in Java and C++

Generic programming has been defined as ‘programming with concepts’ where a concept refers to a family of abstractions. The criteria for generic programming include independence of collections from data types, independence of algorithms that operate on the collection, and the adaptability of the collections. This paper examines and evaluates the support for generic programming in the Java Development Kit (JDK) in comparison to C++'s Standard Template Library (STL). The evaluation will consider both the ‘qualitative’ factors as well as certain ‘quantitative’ factors (i.e. factors that can be measured). The qualitative factors that are considered include: 1. a comparison of the structure and APIs; 2. homogeneity versus heterogeneity; and 3. ease of use (including ease of converting to collection classes, ease of changing collection type, and ease of error handling). The quantitative factors include: 1. compiled size; 2. runtime memory usage; and 3. performance. The results of our evaluative comparisons based on the above factors and certain other criteria are presented at the end. Based on the results, we conclude that the support provided for generic programming in C++'s STL is superior to that provided by JDK. Copyright © 2003 John Wiley & Sons, Ltd.     

一种C++中大数乘法程序

程序模拟了两数相乘的人工竖式算法,利用C++标准模板库中string类接收键盘输入的大数,并用标准模板库vector类存储大数和相乘,解决了基本数据类型表示大数位数有限的问题.     

Localized tensor-based solvers for interactive finite element applications using C++ and Java

This paper presents techniques for solving systems of equations arising in finite element applications using a localized, tensor-based approach. The approach is localized in that a major part of the solution responsibility is delegated to vector degree-of-freedom objects, rather than residing solely in a global solver working on a monolithic data structure. The approach is tensor-based in that the fundamental quantities used for computation are considered to be second-order tensors. The localized data structure strategy provides the benefits of an efficient sparse and symmetric storage scheme without requiring complex implementation code. The tensor-based aspect of the approach can bring substantial performance benefits by increasing the granularity at which solution algorithms deal with their data. Java and C++ implementations of interactive finite element programs are used to demonstrate performance that is competitive with other available solvers, especially in the case of problems for which interactive analysis is feasible on commonly available hardware.     

Scientific computing with Java and C++: a case study using functional magnetic resonance neuroimages

Modern systems for the analysis of image‐based biomedical data, such as functional magnetic resonance imaging (fMRI), require fast computational techniques and rapid, robust development. Object‐oriented programming languages such as Java and C++ provide the foundations for the development of complex data analysis applications. This case study explores the advantages and disadvantages of using these two programming environments for scientific computation as typified in the analysis of fMRI datasets. C++ is well suited for computational and memory optimization while Java is more compliant to the object‐oriented paradigm, supports cross‐platform development and has a rich set of application programming interface (API) classes. The same data model and algorithms were implemented in C++ and Java, and a user interface was developed with the Java API. Comparisons were made with respect to computational performance and ease of development. Benchmarks show that C++ generally outperforms Java, while Java is easier to use, leading to more robust code and shorter development times. However, with the advent of newer just‐in‐time compilers, Java performance is at times comparable to C++. The latest Java virtual machine technology is closing the gap and eventually Java should be a good compromise between efficient algorithm performance and effective application development. Copyright © 2004 John Wiley & Sons, Ltd.     

Java语言与C＋＋语言的比较

Java语言是一门很优秀的语言,具有面向对象、与平台无关、安全、稳定和多线程等优良特性,是目前软件中极为健壮的编程语言。Java已成为网络时代最重要的语言之一。与C＋＋语言比较,Java是一种更纯粹的面向对象程序设计语言。     

Java和C＋＋的继承剖析

C＋＋支持类的多继承，Java采用类的单继承。Java中引入了接口，它定义了一组协议规范，将方法的实现部分放到类中完成，从而将接口继承与实现继承分开。     

Java和C++的继承剖析

C 支持类的多继承,Java采用类的单继承。Java中引入了接口,它定义了一组协议规范,将方法的实现部分放到类中完成,从而将接口继承与实现继承分开。     

Parc++: A parallel C++

PARC++ is a system that supports object-oriented parallel programming in C++. PARC++ provides the user with a set of predefined C++ classes that can easily be used for the construction of parallel C++ programs. With the help of PARC++ objects, the programmer is able to create and start new processes (threads), to synchronize their activities (Blocklock, Monitor) and to manage communication via message passing (Mailbox). PARC++ is written in C++ and currently runs on top of the EMEX operating system on a FORCE machine with 11 processing elements and an EDS (European Declarative System) with 28 processing elements. The paper also contains information about the run-time system model, the implementation and some performance measurements.     

利用JNI实现Java与C＋＋通信

在分析JNI技术框架的基础上,通过实例展示了一种如何实现Java与C＋＋之间通信的方法。实践证明,该方法具有较高的实用价值。     

Comparing observed bug and productivity rates for Java and C++

An experiment was conducted to compare programmer productivity and defect rates for Java and C++. A modified version of the Personal Software Process (PSP) was used to gather defect rate, bug rate, and productivity data on C++ and Java during two real world development projects. A bug is defined to be a problem detected during testing or deployment. A defect is either a bug, or an error detected during compile time. A typical C++ program had two to three times as many bugs per line of code as a typical Java program. C++ also generated between 15 per cent and 50 per cent more defects per line, and perhaps took six times as long to debug. Java was between 30 per cent and 200 per cent more productive, in terms of lines of code per minute. When defects were measured against development time, Java and C++ showed no difference, but C++ had two to three times as many bugs per hour. Statistics were generated using Student's t‐test at a 95 per cent confidence level. Some discussion of why the differences occurred is included, but the reasons offered have not been tested experimentally. The study is limited to one programmer over two projects, so it is not a definitive experimental result. The programmer was experienced in C++, but only learning Java, so the results would probably favour Java more strongly for equally‐experienced programmers. The experiment shows that it is possible to experimentally measure the fitness of a programming language. Copyright © 1999 John Wiley & Sons, Ltd.     

Tice: A real-time language compilable using C++ compilers

Model-based development (MBD) holds the promise to capture potential timing problems in embedded software during the early phases of the development, securing the production of bug-free embedded software. For most MBD approaches, the source code is just an intermediate artifact that can be generated automatically from the models. This assumption clashes with an undeniable fact: a large share of the commercial embedded software exploits existing libraries or is developed using C/C++ natively. A way to reconcile the ambitions of MBD with the use of a programming language is by offering new language constructs and an innovative compilation tool-chain that prevents model error and timing problems “by construction.” However, the persistent popularity of C/C++ among embedded programmers and the limited availability of tools have severely limited the uptake of alternative programming languages for embedded software. Therefore, we propose an original route. Our language proposal, named Tice, has been shaped as a C++ active library. Tice retains full compatibility with existing C++ code, which can be integrated easily into new Tice-based projects. The enforcement of Tice syntax and semantics can be made by a standard C++ compiler, forgoing the need for new tools. In this article, we describe Tice's syntax, semantics, and model of computation and communication. We demonstrate Tice's practical applicability on an industrial scale use-case and give ample evidence for Tice's efficient compilation using off-the-shelf C++ compilers. Finally, we show Tice's code generation process.     

Software project management using PROMPT: A hybrid metrics, modeling and utility framework

In this paper, we present a ‘forward-looking’ decision support framework that integrates up-to-date metrics data with simulation models of the software development process in order to support the software project management control function. This forward-looking approach (called the PROMPT method) provides predictions of project performance and the impact of various management decisions. Tradeoffs among performance measures are accomplished using outcome based control limits (OBCLs) and are augmented using multi-criteria utility functions and financial measures of performance to evaluate various process alternatives. The decision support framework enables the program manager to plan, manage and track current software development activities in the short term and to take corrective action as necessary to bring the project back on track. The model provides insight on potential performance impacts of the proposed corrective actions. A real world example utilizing a software process simulation model is presented.     

Memory allocation costs in large C and C++ programs

Dynamic storage allocation is an important part of a large class of computer programs written in C and C + +. High-performance algorithms for dynamic storage allocation have been, and will continue to be, of considerable interest. This paper presents detailed measurements of the cost of dynamic storage allocation in 11 diverse C and C + + programs using five very different dynamic storage allocation implementations, including a conservative garbage collection algorithm. Four of the allocator implementations measured are publicly available on the Internet. A number of the programs used in these measurements are also available on the Internet to facilitate further research in dynamic storage allocation. Finally, the data presented in this paper is an abbreviated version of more extensive statistics that are also publicly available on the Internet.     

Software and hardware certification of safety-critical avionic systems: A comparison study

To ensure the safety of avionic systems, civil avionic software and hardware regulated by certification authorities must be certified based on applicable standards (e.g., DO-178B and DO-254). The overall safety integrity of an avionic system, comprising software and hardware, should be considered at the system level. Thus, software and hardware components should be planned, developed and certified in a unified, harmonized manner to ensure the integral safety of the entire avionic system. One of the reasons for the high development costs of avionic systems complying with standards may be a lack of sufficient understanding of how to employ these standards efficiently. Therefore, it is important to understand the similarities and differences between DO-178B and DO-254 to effectively manage the processes required by these standards, to minimize cost, and to ultimately ensure the safety of the entire avionic system. Thus, the goal of this paper is to compare various aspects of DO-178B and DO-254 comprehensively. The paper may serve as a useful supplementary material for the practitioner to understand the rationales behind and the differences between two main standards used in avionic industries.     

基于C++及其扩展语言的动态剖析

程序优化是提高程序运行效率的重要步骤,程序剖析是程序优化的第一步。对于串行语言,程序剖析代码是由编译器通过一个命令行开关自动插入。但是,大部分并行语言编译器都不具有这个功能。该文以并行C++语言的可移植的动态剖析程序(profiler)为例,从两方面对问题进行了论述:首先给出实现可移植动态剖析程序的一般方法;然后分析一个用于pC++插桩(Instrumentation)工具。     

ConC++:C++的一种并发扩充语言

提出一种对Ｃ＋＋进行并发扩充的语言ＣｏｎＣ＋＋．ＣｏｎＣ＋＋是一个并发面向对象语言,它采用并发类和保护类的机制支持并发,并发类有一个主动函数,一旦对象被创建,这个主动函数就开始执行;保护类封装了一组数据和对数据的操作,它没有自己的线程,而且是用来实现对并发类对象的同步、互斥和通信,这种集中控制对象的并发的方法体现了对象的自治性特点,减少了上下切换和死锁发生的可能,从而提高了程序的性能。     

Software fault prediction metrics: A systematic literature review

ContextSoftware metrics may be used in fault prediction models to improve software quality by predicting fault location.ObjectiveThis paper aims to identify software metrics and to assess their applicability in software fault prediction. We investigated the influence of context on metrics’ selection and performance.MethodThis systematic literature review includes 106 papers published between 1991 and 2011. The selected papers are classified according to metrics and context properties.ResultsObject-oriented metrics (49%) were used nearly twice as often compared to traditional source code metrics (27%) or process metrics (24%). Chidamber and Kemerer’s (CK) object-oriented metrics were most frequently used. According to the selected studies there are significant differences between the metrics used in fault prediction performance. Object-oriented and process metrics have been reported to be more successful in finding faults compared to traditional size and complexity metrics. Process metrics seem to be better at predicting post-release faults compared to any static code metrics.ConclusionMore studies should be performed on large industrial software systems to find metrics more relevant for the industry and to answer the question as to which metrics should be used in a given context.     

用Visual C++编写典型测控软件

给出了工业自动化领域的应用测控软件编制的一般流程,并对编程中可能遇到的几个关键问题分别做了介绍,给出了解决方案.     

基于Java 与C++联合编程实现网络环境下遥感影像的切割算法

随着GIS与RS的集成、数字地球、信息共享等研究工作的深入开展,如何实现遥感影像在Internet环境下的快速发布就成为一项迫切的研究工作。目前比较成功的影像发布方法是将影像重采样、分层切割进而建立影像金字塔存储模型。网络环境下遥感影像的切割算法是解决上述影像金字塔问题的有效途径。首先讨论了以JNIOava Native Interface）技术为基础实现Java与C＋＋联合编程的一些关键问题。进而,以Java与C＋＋联合编程为基础,实现了面向Internet网络环境的、基于B/S架构的遥感影像切割算法。这种实现方法结合了C＋＋语言在图像处理方面的高效性和Java语言在网络编程方面的优越性,从而为遥感影像的网络快速发布提供了保障。实践证明该方案可行,且算法稳定可靠、易于操作。