Advanced testing and debugging support for reactive executable DSLs

Software and Systems Modeling - Executable Domain-Specific Languages (xDSLs) allow the definition and the execution of behavioral models. Some behavioral models are reactive, meaning that during...     

Translator design to support run-time debugging

Designers and implementors of high-level language translators can, with relatively little extra effort, greatly facilitate run-time symbolic debugging. Practical suggestions are presented, based on experiences gained from interfacing several compilers with a run-time debugging system.     

Adding debugging support to the Prometheus methodology

This paper describes a debugger which uses the design artifacts of the Prometheus agent-oriented software engineering methodology to alert the developer testing the system, that a specification has been violated. Detailed information is provided regarding the error which can help the developer in locating its source. Interaction protocols specified during design, are converted to executable Petri net representations. The system can then be monitored at run time to identify situations which do not conform to specified protocols. A process for monitoring aspects of plan selection is also described. The paper then describes the Prometheus Design Tool, developed to support the Prometheus methodology, and presents a vision of an integrated development environment providing full life cycle support for the development of agent systems. The initial part of the paper provides a detailed summary of the Prometheus methodology and the artifacts on which the debugger is based.     

精品课程教学录像的建设现状分析与建议

教学录像是精品课程建设的重要内容之一。为了开发集教学性、科学性、技术性与艺术性于一体的精品课程教学录像,针对精品课程教学录像的性质,参照其上网技术指标及网上浏览的特点,对其建设现状进行分析,并提出了精品课程教学录像建设的建议。     

A practical approach to testing GUI systems

GUI systems are becoming increasingly popular thanks to their ease of use when compared against traditional systems. However, GUI systems are often challenging to test due to their complexity and special features. Traditional testing methodologies are not designed to deal with the complexity of GUI systems; using these methodologies can result in increased time and expense. In our proposed strategy, a GUI system will be divided into two abstract tiers—the component tier and the system tier. On the component tier, a flow graph will be created for each GUI component. Each flow graph represents a set of relationships between the pre-conditions, event sequences and post-conditions for the corresponding component. On the system tier, the components are integrated to build up a viewpoint of the entire system. Tests on the system tier will interrogate the interactions between the components. This method for GUI testing is simple and practical; we will show the effectiveness of this approach by performing two empirical experiments and describing the results found.

Tailoring IT support to communities of practice

Many organizations have benefited from recognizing communities of practice (COPs) operating in their midst. By identifying a group as a COP, an organization has made a critical skill area visible. Without this awareness it would be more likely, for example, that the corporate talent in auditing software processes could quietly disappear. With the importance of COPs established, organizations can now turn their attention to ensuring that their IT and knowledge management systems enable COPs to flourish. A simple folder on a corporate server to share documents is an example of such support. More comprehensive support to a COP may include virtual space on the corporate intranet for synchronous and asynchronous collaboration, expertise location, and content structuring (B. Lewis, "On-Demand KM: A Two-Tier Architecture", IT Professional, Jan.-Feb. 2002, pp. 27-33). As organizations decide how to support COPs, they should know that COPs are not in any way uniform entities. There is wide variation among COPs and understanding these differences can go a long way toward providing support that is truly well matched to the needs of each one. Two observations are keys to understanding the variety of COPs that are candidates for organizational support: The number of potential COPs is great, and, there are many kinds of groups and communities; not all of them are COPs.     

GUI testing: pitfalls and process

Given their increased importance, testing graphical user interfaces (GUI) for correctness can enhance the entire system's safety, robustness, and usability. But GUI remain a neglected test research area.     

A simulator for real-time software debugging and testing

A software simulator can be built to facilitate debugging and testing of real-time programs. This paper describes a simulator designed to operate in three modes: simulation, debugging and process monitoring. In the simulation mode, it simulates a Z80-based microcomputer and can be used to execute programs written in the Z80-assembler language. In the debugging mode, it provides facilities for interactive debugging on the instruction level. The simulator's unique feature is the process monitoring mode. It displays the activities among processes being executed concurrently under the control of a real-time executive and thus allowing direct observation of dynamic program behaviour at the process level.     

Comparison of adaptive random testing and random testing under various testing and debugging scenarios

Adaptive random testing is an enhancement of random testing. Previous studies on adaptive random testing assumed that once a failure is detected, testing is terminated and debugging is conducted immediately. It has been shown that adaptive random testing normally uses fewer test cases than random testing for detecting the first software failure. However, under many practical situations, testing should not be withheld after the detection of a failure. Thus, it is important to investigate the effectiveness with respect to the detection of multiple failures. In this paper, we compare adaptive random testing and random testing under various scenarios and examine whether adaptive random testing is still able to use fewer test cases than random testing to detect multiple software failures. Our study delivers some interesting results and highlights a number of promising research projects. Copyright © 2011 John Wiley & Sons, Ltd.     

A debugging and testing tool for supporting software evolution

This paper describes a tool for debugging programs which develop faults after they have been modified or are ported to other computer systems. The tool enhances the traditional debugging approach by automating the comparison of data structures between two running programs. Using this technique, it is possible to use early versions of a program which are known to operate correctly to generate values for comparison with the new program under development. The tool allows the reference code and the program being developed to execute on different computer systems by using open distributed systems techniques. A data visualisation facility allows the user to view the differences in data structures. By using the data flow of the code, it is possible to locate faulty sections of code rapidly. An evaluation is performed by using three case studies to illustrate the power of the technique.     

数字录像机界面的研究及实现

BSP-15是美国Equator公司新出的一款数字处理芯片,适用于单芯片、高带宽的解决方案。eCos是一种开放源代码的实时操作系统。基于这样平台的数字录像机,是当前的一个研究方向。本文介绍图形用户界面的设计与实现。全部界面代码是用C语言写成。经过测试,这个界面运行稳定,效率高,进一步开发后可以做为产品使用。     

Use of inertial sensors to support video tracking

One of the biggest obstacles to building effective augmented reality (AR) systems is the lack of accurate sensors that report the location of the user in an environment during arbitrary long periods of movements. In this paper, we present an effective hybrid approach that integrates inertial and vision‐based technologies. This work is motivated by the need to explicitly take into account the relatively poor accuracy of inertial sensors and thus to define an efficient strategy for the collaborative process between the vision‐based system and the sensor. The contributions of this papers are threefold: (i) our collaborative strategy fully integrates the sensitivity error of the sensor: the sensitivity is practically studied and is propagated into the collaborative process, especially in the matching stage (ii) we propose an original online synchronization process between the vision‐based system and the sensor. This process allows us to use the sensor only when needed. (iii) an effective AR system using this hybrid tracking is demonstrated through an e‐commerce application in unprepared environments. Copyright © 2007 John Wiley & Sons, Ltd.     

A noninterference monitoring and replay mechanism for real-timesoftware testing and debugging

A noninterference monitoring and replay mechanism using the recorded execution history of a program to control the replay of the program behavior and guarantee the reproduction of its errors is presented. Based on this approach, a noninterference monitoring architecture has been developed to collect the program execution data of a target real-time software system without affecting its execution. A replay mechanism designed to control the reproduction of the program behavior as well as the examination of the states of the target system and its behavior is presented. The monitoring system has been implemented using a Motorola 68000 computer in a Unix system environment. An example is used to illustrate how the mechanism detects timing errors of real-time software systems     

LVMSR: an efficient algorithm to multicast layered video

Layered video is a video-compression technique to encode video data in multiple layers. It typically consists of a base layer and some additional layers that provide enhanced video quality. The multicasting operation of layered video consists of many receivers dynamically joining and leaving different multicast sessions of different layers depending on their network condition. A layered video multicasting system needs to satisfy: (i) bounded end-to-end delay from the video source to each receiver; (ii) minimum total cost; and (iii) minimum delay jitter between the various video streams received by each receiver. The problem of computing such data distribution paths is NP-complete. This paper presents a new heuristic algorithm, called layered video multicast super-tree routing algorithm, with O(Rn²) time complexity and O(R²) message complexity, where n is the number of nodes in the network and R is the receiver group size. Our investigation shows that the multicast data paths computed by our algorithm can always satisfy the delay constraint with reasonably low total cost.     

Optimal allocation of testing effort during testing and debugging phases: a control theoretic approach

Allocation of efforts to a software development project during the testing phase is a multifaceted task for software managers. The challenges become stiffer when the nature of the development process is considered in the dynamic environment. Many software reliability growth models have been proposed in last decade to minimise the total testing-effort expenditures, but mostly under static assumption. The main purpose of this article is to investigate an optimal resource allocation plan to minimise the cost of software during the testing and operational phase under dynamic condition. An elaborate optimisation policy based on the optimal control theory is proposed and numerical examples are illustrated. This article also studies the optimal resource allocation problems for various conditions by examining the behaviour of the model parameters and also suggests policy for the optimal release time of the software. The experimental results greatly help us to identify the contribution of each selected parameter and its weight.     

Using formal specifications to support software testing

Formal specifications become more and more important in the development of software, especially but not only in the area of high integrity system design. In this paper it is demonstrated, how, apart from the specification phase, further benefits may be drawn from formal specifications for checking the implementation against the specification. It is shown how the specification can be used for systematically deriving test input data and for automatically evaluating test results. The approach is illustrated using the specification language Z. The same principles may be applied to other specification languages. The approach allows a high degree of automation, drastically improving productivity and quality of the testing process.     

面向GUI软件测试的交互图生成及其实现*

从控件的信息入手,研究了界面的控件间功能交互关系,提出了基于交互图的GUI测试方法,并开发了一个基于交互图的GUI测试工具GUITester.它能自动生成交互图和测试用例,大大提高了GUI软件测试的效率和覆盖率.     

一种嵌入式视频记录系统的设计与实现

文章介绍了基于嵌入式控制模块DIMM-PC/520IU和专用视频处理芯片SZ1510硬件平台的MPEG-1视频记录系统的设计和实现,讨论了总体原理和架构,阐述了核心硬件模块的设计和视频记录系统的软件设计.     

A class library for implementing, testing, and debugging concurrent programs

We describe the Modern Multithreading (MM) class library. MM is a class library consisting of thread and synchronization classes that provide significant support for testing and debugging multithreaded programs. The synchronization classes implement commonly used synchronization objects such as semaphores, monitors, and asynchronous and synchronous message passing channels, for programs that run on a single computer or on a distributed system. MM uses controlled executions to provide program tracing and replay and to support a number of implementation-based and specification-based testing techniques, including non-deterministic and deterministic testing and several forms of reachability testing. MM is portable and easy to use, and has been implemented in Java and C++, with C++ versions for the POSIX Pthreads library and for the Windows Win32 API.     

RED-VBR: a renegotiation-based approach to support delay-sensitive VBR video

Previous approaches to supporting video on packet-switched networks include deterministic service, statistical service, predicted service, and feedback-based schemes. These schemes represent different tradeoffs in quality of service (QOS), achievable network utilization, and method of dealing with overload. In this paper, we propose a new service called REnegotiated Deterministic Variable Bit Rate Service (RED-VBR) that attempts to strike an efficient balance with the above tradeoffs. The approach is based on deterministic guarantees with client-controlled renegotiation of traffic and QOS parameters and graceful adaptation during overload periods. We introduce a connection admission control algorithm for RED-VBR which bounds the renegotiation failure probability. We evaluate the scheme using two traces of MPEG-compressed video and show that, even with simple renegotiation polices and relatively low renegotiation frequencies, high network utilization in the range of 50–80% can be achieved. For traffic that is bursty over long intervals, this represents a 100–150% improvement in network utilization compared to deterministic service. Compared to statistical and predicted service, our approach allows more graceful and client-controlled QOS degradation during overload periods.