测试Java异常处理机制的方法

异常处理机制能增强程序运行的可靠性,提高软件的健壮性.然而,如果异常处理机制使用不当,会带来许多潜在的错误,因而很有必要对程序的异常处理结构进行测试.提出了一种识别被测程序中的所有异常变量"定义-使用"关系的方法,并使用一个异常的定义-捕获度量来计算异常定义-使用链的测试覆盖.最后设计了一种异常分析及测试的原型工具.     

Ct coverage — initial results

Software testing techniques based upon automated analysis of control flow are useful for improving software reliability. The fundamental types of control flow analysis, in ascending order of effectiveness, are statement, branch, and path coverage. Automated tools that perform branch coverage analysis are now accepted practice and researchers are exploring the area that exists between branch and path analysis. Path testing is complicated by the huge number of paths in ordinary programs and by anomalies, such as infeasible paths. The Ct testing strategy is a method for obtaining a manageable set of path classes by specifying a minimum iteration count k. The Ct test coverage metric is a measurement of the proportion of Ct path classes that are exercised within a program. This paper describes an initial experiment in which a special, automated tool was used to evaluate the Ct coverage of tests for a C program of significant size. The results of the study showed that high values of branch coverage may not necessarily imply high path coverage, that approximately 15% of the functions analysed were too complex to analyse effectively, and that the majority of the remaining functions achieved on the order of 11% Ct k=1 coverage. Experimental work in the attainment of high Ct coverage suggests the development of a new, more efficient software testing strategy, which combines Ct path and data flow analysis.     

专家系统规则库覆盖度量的研究及实践

针对专家系统规则库的软件测试和评价是保证专家系统质量与可靠性的重要环节。基于数据流的结构化测试技术,提出了一种规则库执行流图RBEF,用于描述规则库中不同规则之间相互连结、制约关系,进而给出了一组规则库覆盖度量准则和测试用例的设计方法,最后讨论了一个已实现并付诸于应用的基于RBEF的软件测试工具ESRTS。     

An analytical approach to the deployment quality of surveillance wireless sensor networks considering the effect of jammers and coverage holes

The requirements of surveillance wireless sensor networks, such as latency and reliability provisions, are directly related to the deployment quality, which is an indicator of the sensing capability of the network. The determination of the deployment quality is hindered by various factors that cause coverage holes, such as the existence of jammers and destruction of sensors. This paper presents an analytical deployment quality measure in terms of network parameters, including the sensor count, sensing coverage, coverage hole count, coverage hole area size and deployment area size. Assuming a random deployment model for both sensors and holes, our method determines the probability of detection of a target following a linear trajectory by a single sensor and generalizes it to derive the probability of detection in a network with coverage holes. The overall probability of detection is used as the network quality measure and is proposed as a suitable metric under sensor loss assumptions. The proposed deployment quality metric (DQM) is based on the shortest path strategy to provide a conservative estimation for the intruder detection performance. We show that it provides a good estimation of the actual deployment quality with given coverage hole and jamming area properties. Our metric is suitable for real life and simulation scenarios and is computationally inexpensive compared to both simulation based and distributed quality measurements.     

Location pairs: a test coverage metric for shared-memory concurrent programs

We present a coverage metric targeted at shared-memory concurrent programs: the Location Pairs (LP) coverage metric. The goals of this metric are (i) to measure how thoroughly a program has been tested from a concurrency standpoint, i.e., whether enough qualitatively different thread interleavings have been explored, and (ii) to guide testing towards unexplored concurrency scenarios. This metric was inspired by an access pattern known to lead to high-level concurrency errors in industrial software and in the literature. We built a monitoring tool to measure LP coverage of test programs. We used the LP metric for interactive debugging, and compared LP coverage with other concurrency coverage metrics on Java benchmarks. We demonstrated that LP coverage corresponds better to concurrency errors, is a better measure of how well a program is exercised concurrency-wise by a test set, reaches saturation later than other coverage metrics, and is viable and useful as an interactive testing and debugging tool.     

Parallel energy-efficient coverage optimization with maximum entropy clustering in wireless sensor networks

Energy constraint is an important issue in wireless sensor networks. This paper proposes a parallel energy-efficient coverage optimization mechanism to optimize the positions of mobile sensor nodes based on maximum entropy clustering in large-scale wireless sensor networks. According to the models of coverage and energy, stationary nodes are partitioned into clusters by maximum entropy clustering. After identifying the boundary node of each cluster, the sensing area is divided for parallel optimization. A numerical algorithm is adopted to calculate the coverage metric of each cluster, while the lowest cost paths of the inner cluster are used to define the energy metric in which Dijkstra’s algorithm is utilized. Then cluster heads are assigned to perform parallel particle swarm optimization to maximize the coverage metric and minimize the energy metric where a weight coefficient between the two metrics is employed to achieve a tradeoff between coverage area and energy efficiency. Simulations of the optimization mechanism and a target tracking application verify that coverage performance can be guaranteed by choosing a proper weight coefficient for each cluster and energy efficiency is enhanced by parallel energy-efficient optimization.     

面向回归测试的代码变更影响度量模型

软件待测版本相对上一个版本的代码变更,会对已有特性带来潜在的质量风险,这一风险水平直接与回归测试用例的优先级相关联.回归测试设计过程中的一个重要问题是如何衡量代码变更对回归测试用例优先级的影响.本文在回归测试用例优先级评估模型的基础上,从测试覆盖的角度建立起回归测试用例与代码变更的直接关联,从代码整体耦合性的角度建立起回归测试用例与代码变更的间接关联,分析了代码变更对回归测试的显性影响和隐性影响,进而结合回归测试用例优先级的评估要求提出了一个新的度量模型.实验结果显示,使用该模型度量代码变更对回归测试用例优先级的影响水平,可以得到比较全面和客观的定量结果,从而为回归测试用例优先级的评估提供有效的支持.     

针对可观测性语句覆盖准则的RTL激励生成

传统的语句覆盖准则只考虑语句的可控制性,忽略其可观测性,这可能导致表面上很高的覆盖率数据所蕴含的可信度不高．鉴于此,可观测性覆盖评估准则被提了出来．随着设计规模不断加大,该准则变得越来越重要．首先提出一种可观测性信息的表征方式以及可观测性判定规则,在此基础上,提出一种针对可观测性语句覆盖准则的RTL激励生成方法．这是一种基于模拟的方法,它以所有未观测语句的分布作为启发式信息,指导激励生成．实验结果显示,提出的方法是高效的．     

Coverage rate calculation in wireless sensor networks

The deployment of sensors without enough coverage can result in unreliable outputs in wireless sensor networks (WSNs). Thus sensing coverage is one of the most important quality of service factors in WSNs. A useful metric for quantifying the coverage reliability is the coverage rate that is the area covered by sensor nodes in a region of interest. The network sink can be informed about locations of all nodes and calculate the coverage rate centrally. However, this approach creates huge load on the network nodes that had to send their location information to the sink. Thus, a distributed approach is required to calculate the coverage rate. This paper is among the very first to provide a localized approach to calculate the coverage rate. We provide two coverage rate calculation (CRC) protocols, namely distributed exact coverage rate calculation (DECRC) and distributed probabilistic coverage rate calculation (DPCRC). DECRC calculates the coverage rate precisely using the idealized disk graph model. Precise calculation of the coverage rate is a unique property of DECRC compared to similar works that have used the disk graph model. In contrast, DPCRC uses a more realistic model that is probabilistic coverage model to determine an approximate coverage rate. DPCRC is in fact an extended version of DECRC that uses a set of localized techniques to make it a low cost protocol. Simulation results show significant overall performance improvement of CRC protocols compared to related works.     

Testing network management software

A fourth wave of computer-based network management systems is here. Experienced network managers worry about the reliability of software. This discussion provides ways of testing software to improve software and system reliability, and it proposes a reliability footprint in-process metric to monitor the effectiveness of a test program. Systematic ways of moving from debugging to assuring reliable network management systems are emphasized.     

基于决策熵的决策树规则提取方法

在决策表中,决策规则的可信度和对象覆盖度是衡量决策能力的重要指标。以知识粗糙熵为基础,提出决策熵的概念,并定义其属性重要性;然后以条件属性子集的决策熵来度量其对决策分类的重要性,自顶向下递归构造决策树;最后遍历决策树,简化所获得的决策规则。该方法的优点在于构造决策树及提取规则前不进行属性约简,计算直观,时间复杂度较低。实例分析的结果表明,该方法能获得更为简化有效的决策规则。     

考虑测试工作量与覆盖率的软件可靠性模型

为了进一步提升现有非齐次泊松过程类软件可靠性增长模型的拟合与预计精度,首先,提出一个同时考虑测试工作量与测试覆盖率的NHPP类软件可靠性建模框架.在此基础上,将变形S型测试工作量函数(IS-TEF)以及Logistic测试覆盖率函数(LO-TCF)带入该建模框架,建立了一个新的软件可靠性增长模型,即IS-LO-SRGM.同时,还对利用该框架进行建模过程中的两个重要问题进行了描述与分析,即如何确定具体的TEF和TCF以及模型参数估计.然后,在两组真实的失效数据集上,利用该建模框架建立了最为合适的增长模型,即IS-LO-SRGM,并将该模型与8种经典NHPP模型进行对比.实例验证结果表明,所提出的IS-LO-SRGM模型具有最为优秀的拟合与预计性能,从而证明新建模框架的有效性和实用性.最后,对不完美排错情况进行了初步的讨论与建模分析.     

动态可靠性约束的多阶段测试资源分配研究

为满足测试资源分配过程中用户对软件可靠性的需求,构建一种动态可靠性约束的多阶段多目标测试资源分配模型DRC-MSMOTRA。从理论上分析不同阶段满足可靠性约束的测试时间下限并设计相应的种群初始化策略,结合参数估计、加权归一化方法和多目标差分进化,提出一种动态可靠性约束的多阶段多目标测试资源分配算法MS-DRC-GDE3。实验结果表明,与MSMOTRA模型相比,DRC-MSMOTRA模型在2种不同规模的软件系统上所获解的覆盖值分别提高约62和59个百分点,与MS-GDE3算法相比,MS-DRC-GDE3算法在2种软件系统上所获解的覆盖值分别提高约69和80个百分点,即所提模型和算法能够根据用户对可靠性的需求来为用户提供更多更优的测试资源分配方案。     

无线传感网络中覆盖能效动态控制优化策略

能量约束是无线传感网络测量控制的关键问题之一.本文针对移动节点位置优化问题,提出了无线传感网络通信能耗评价指标,采用微粒群优化策略更新节点位置,使无线传感网络具有更强的灵活性和能效性.利用Dijkstra算法获得网络最优通信路径计算能耗评价指标.采用动态能量控制策略使空闲节点进入睡眠状态减少网络运行能耗.通过优化能量指标降低了通信能耗,实现了无线传感网络覆盖与通信能量消耗的合理均衡.对移动目标跟踪仿真表明,覆盖能效优化算法与动态能量控制策略相结合提高了无线传感网络覆盖的能效性.     

A binomial software reliability model based on coverage of structural testing criteria

A new approach to software reliability modeling is discussed where variables indirectly related with software reliability are used to provide additional information for the modeling process. Previous studies, empirical and theoretical evidences, and results from experiments indicate that there is a strong relationship between software reliability and coverage of program elements required to be exercised by structural testing criteria. This paper develops a binomial type coverage-based software reliability model through the definition of a coverage-based failure rate function. The Binomial software reliability Model Based on Coverage—BMBC—is proposed and discussed. In the BMBC test data between failures is used instead of time as independent variable; the model was assessed with test data from a real application, making use of the following structural testing criteria: all-nodes, all-edges, and potential-uses—a data-flow based family of testing criteria. The results from our experiments have shown that our modeling approach has some advantages over some traditional reliability models and points to a very promising research direction in software reliability.

Integrating testing with reliability

The activities of software testing and reliability are integrated for the purpose of demonstrating how the two activities interact in achieving testing efficiency and the reliability resulting from these tests. Integrating means modeling the execution of a variety of tests on a directed graph representation of an example program. A complexity metric is used to construct the nodes, edges, and paths of the example program. Models are developed to represent the efficiency and achieved reliability of black box and white box tests. Evaluations are made of path, independent path, node, program construct, and random tests to ascertain which, if any, is superior with respect to efficiency and reliability. Overall, path testing has the edge in test efficiency. The results depend on the nature of the directed graph in relation to the type of test. Although there is no dominant method, in most cases the tests that provide detailed coverage are better. For example, path testing discovers more faults than independent path testing. Predictions are made of the reliability and fault correction that results from implementing various test strategies. It is believed that these methods can be used by researchers and practitioners to evaluate the efficiency and reliability of other programs. Copyright © 2008 John Wiley & Sons, Ltd.     

使用时间冗余保证处理器的可靠性

在SOR模型的基础上提出了BRO-SOC(Backward Recovery Oriented Sphere Of Correctness)框架。在该框架的指导下提出了DoubleRun容错处理器方案。DoubleRun使用确定性重播(Deterministic Replay)技术保证处理器的可靠性。由于Double-Run将故障的检测边界设置在BRO-SOC框架的SOC2一级,因此只需对L1cache进行适当扩展即可容忍处理器流水线中的瞬态故障,由于它不需改动现有的处理器流水线,故相比于其他方案对处理器流水线的性能影响更小。利用SPEC2000的部分程序测试了DoubleRun的无故障性能。为将DoubleRun与其他容错方案(DCC、Slipstream)作横向比较而提出了衡量指标TAC(Timeand Area Cost)。实验结果表明,DoubleRun在提供全故障覆盖率的情况下仅增加了6.9%的面积开销和89.8%的时间开销,其TAC虽然比Slipstream大7%但却可以提供全面的故障覆盖率,其故障覆盖能力与DCC相同但TAC却比后者小14%。     

Web应用软件的结构测试研究

为了保证Web应用的质量和可靠性,Web应用软件测试受到了人们越来越多的重视。有效的Web应用软件的测试依赖于对其进行充分的分析和理解,掌握其内部的控制流和数据流信息,构建结构模型实施基于覆盖率的结构测试。提出了一种Web应用软件结构模型,它分为5级,分别为函数级、函数群级、对象级、对象群级和应用级,且基于此结构模型,提出了测试用例的设计和选择的方法,从而更好地支持了Web应用软件的结构测试。     

基于缺陷的软件可靠性度量方法研究

针对软件可靠性度量研究中的一些问题,提出了以缺陷度量为软件可靠性度量的一种方法。首先将缺陷度量方法按照软件度量的一般方法进行研究和探讨;其次,以正交缺陷为基础,提出了定量的缺陷统计方法,这种方法能够更好地描述缺陷的性质,对相关信息可进行分类统计、分析,为过程改进提供依据;最后,提出了一些定性的缺陷分析方法,可充分挖掘缺陷的潜在信息。按照软件度量的步骤,通过定性和定量相结合的方法,可以很好地度量软件可靠性,并实时提高软件可靠性。     

Some issues in software reliability assessment

The debate between those who prefer formal methods and those who advocate the use of reliability-growth models in the assessment of software reliability continues. Some issues arising from this conflict are raised and discussed, beginning with the definition of quantified software reliability. After arguing that the stochastic modelling approach is conceptually sound, its possible relationship with the structure of the software is discussed. Evidence that certain structural counts can be used in place of time as the argument in reliability growth models is reported. The question of the extent to which the many non-stochastic metrics now available contribute to software reliability quantification is aired. A relationship between reliability and a hierarchy of coverage metrics is reported, which may help to draw together the modellers and the testers.