基于AOP技术的通用线程监控平台GTMP*

提出并实现了基于AOP技术的通用线程监控平台。借助AOP的需求空间分离实现技术,使用该平台的原系统不必事先具有监控能力,该平台可以在不手动改变系统源代码的情况下通过工具自动植入系统内部,为系统注入监控功能,实现对运行线程信息的监视和对指定线程运行速度的变换,实现对整个系统运行行为的控制。     

基于AOP技术的通用线程监控平台GTMP

提出并实现了基于AOP技术的通用线程监控平台.借助AOP的需求空间分离实现技术,使用该平台的原系统不必事先具有监控能力,该平台可以在不手动改变系统源代码的情况下通过工具自动植入系统内部,为系统注入监控功能,实现对运行线程信息的监视和对指定线程运行速度的变换,实现对整个系统运行行为的控制.     

基于AOP技术的通用线程监控平台的研究与实现

在传统的OOP编程中,由于需求空间是N维而实现空间是一维的,导致了软件开发中横切关注点的代码纠缠问题,严重影响了软件的质量.作为OOP的补充,AOP很好地解决了横切关注点带来的问题,提供了核心关注点和横切关注点互相分离的解决方案.本文从具体工程中开发线程监控这一需求所暴露的问题出发,提出了为什么需要AOP编程;然后着重讨论如何通过AOP技术解决这一问题,提出并实现了基于AOP技术的通用线程监控平台.该平台可以在不手工改变系统源代码的情况下通过工具植入系统内部,实现对运行线程信息的监视、对指定线程运行速度的变换和对整个系统运行行为的控制.     

基于动态AOP的构件交互行为监测器

在开放、动态的网络环境中,分布式软件呈现出规模庞大、松散聚合、行为复杂等特点,为有效监测其交互行为,提出了基于动态AOP的监测器模型,使得监测器能以更为灵活、松散、透明的方式融入目标系统;利用动态织入机制,能在目标系统运行过程中动态增加或删除监测器,提高了监测的动态性;并在此基础上实现了该监测器并应用于分布式电子商务应...     

DOTNET平台组件配置工具的设计与实现

在研究了DOTNET平台Castle框架的基础上设计出了一个反转控制(IOC)和面向切面编程(AOP)配置文件自动生成的可视化工具,该工具为程序员快速完成应用系统中IOC和AOP配置文件提供了一个很好的平台,该工具后来还被作成了插件版本.     

一个基于字节码迁移的动态AOP优化算法

AOP通过功能方面代替对象能大幅度提高系统的复用率,系统结构简洁、清晰.静态AOP编译组织运行效率高,但需使用专用编译器进行预编译,不能与OOP兼容;动态AOP和静态AOP相比,灵活性高,且语法结构与OOP完全兼容,方便系统开发和移植.但由于动态AOP基于拦截器模式实现,且在运行时组织的特性使其效率低下,AOP组件通常为系统核心组件,对动态AOP的优化对系统性能有重要意义.提出了一种基于字节码迁移技术的动态AOP优化算法,有效提高了动态AOP性能,接近静态AOP的运行效率.     

基于三值语义的软件运行时验证方法

运行时验证技术是对传统的程序正确性保证技术如模型检验和测试的有效补充。模型检验和测试都试图验证系统的所有可能执行路径的正确性,而运行时验证关注的是系统的当前执行路径。本文提出一种基于三值语义的软件运行时验证方法,一方面该方法提供了从代码插装、系统底层信息提取到监控器生成、验证系统运行轨迹是否满足性质规约的完整的解决方案;另一方面基于三值语义的监控器有发现一条无穷运行轨迹的最小好(坏)前缀的能力,从而使得监控器能尽可能早的发现性质违背。同时,我们开发了基于三值语义的软件运行时验证原型工具并针对案例进行了分析。     

基于AOP的性能监测系统的研究与实现

提出一种基于动态AOP的监测器模型及其实现,它能够对现有的、已在运行的系统进行最灵活和能耗最小的代码级性能分析。利用AOP动态织入机制,可在目标系统运行过程中动态添加或删除监测器,从而提高监测的灵活性。     

卫星测控站频谱监测系统设计方案及实现

为解决卫星测控站人工监测下行中频信号效率低、无自动化的频谱处理等问题,设计并实现了一种基于开关矩阵和频谱仪的多路频谱监测系统;首先介绍了该系统的硬件组成,然后介绍了系统软件设计方案,针对系统功能,提出了若干个频谱监测相关的处理算法,包括基于SCPI的频谱实时监测、基于临界线的异常信号检测、基于频谱轨迹的频谱录像与回放以及一种快速的遥控命令捕获等算法,最后通过试验说明系统满足频谱监测的需求;实际应用结果表明,该系统运行稳定可靠,各算法是实用有效的。     

面向方面测试技术的研究

面向方面编程运用方面模块化横切关注点,构建出易于理解、易于扩展以及高质量的软件.然而,软件测试是软件质量保证的关键因素,那么开发有效的测试方法来检验AOP的正确性就显得十分重要.本文简述了面向方面编程的基本概念,详细介绍了四种AOP测试方法,并根据检验错误类型的能力对比了其中部分方法的性能,分析了AOP测试方法的研究现状、面临的技术问题以及未来的研究工作,最后总结了开发AOP测试技术和工具的重要性.     

Exploiting traces in static program analysis: better model checking through {{\tt printf}}s

From operating systems and web browsers to spacecraft, many software systems maintain a log of events that provides a partial history of execution, supporting post-mortem (or post-reboot) analysis. Unfortunately, bandwidth, storage limitations, and privacy concerns limit the information content of logs, making it difficult to fully reconstruct execution from these traces. This paper presents a technique for modifying a program such that it can produce exactly those executions consistent with a given (partial) trace of events, enabling efficient analysis of the reduced program. Our method requires no additional history variables to track log events, and it can slice away code that does not execute in a given trace. We describe initial experiences with implementing our ideas by extending the CBMC bounded model checker for C programs. Applying our technique to a small, 400-line file system written in C, we get more than three orders of magnitude improvement in running time over a naïve approach based on adding history variables, along with fifty- to eighty-fold reductions in the sizes of the SAT problems solved.     

一种用于多Agent系统的领域工程方法

现有的面向Agent的软件工程方法没有考虑多Agent系统中的横切关切并且存在Agent概念过于抽象,不能有效地指导详细设计和实现的问题。该文提出一个基于多Agent领域元模型MBGDE,开发多Agent领域的领域特定语言MASDSL和多Agent框架GMAF,集成面向方面的软件开发技术以捕捉横切关切,使用产生器将Agent概念映射成具体设计和实现,提高了多Agent系统的开发效率和质量。     

Hardware-assisted energy monitoring architecture for micro sensor nodes

In this paper, we present a hardware-assisted energy monitoring architecture, HEMA, which provides power information for individual system components in micro sensor nodes. HEMA gives information on how the system components of sensor nodes spend energy while applications are running. To develop a practical runtime monitoring system we used a power monitoring technique based on a battery monitor IC (Integrated Circuit) which is typically used in embedded systems. HEMA uses a software technique to monitor device usage patterns, and combines it with hardware-assisted power information in runtime. However, the battery monitor IC has problems in monitoring individual devices. In this paper, we developed a software technique to supplement its drawbacks. To evaluate the proposed system, we built a micro sensor node with battery monitor IC. We operated real applications on the sensor node and conducted a comparative analysis with a dedicated power monitor. Our experiment results show that HEMA indeed provides a suitable architecture for runtime power analysis with low overhead.     

ASSISTing Management Decisions in the Software Inspection Process

Software inspection is a valuable technique for detecting defects in the products of software development. One avenue of research concerns the development of computer support tools that will hopefully lead to even greater improvements to the software inspection process. A number of prototype systems have been developed, but to date all suffer from some fundamental limitations. One of the most serious of these concerns is the lack of facilities to monitor the inspection process, and thereby to provide the moderator with quantitative information on the performance of the process. This paper commences by briefly describing work undertaken at Strathclyde into research in the area of computer support for software inspection (ASSIST). It then outlines a measurement component based on capture–recapture techniques that has been introduced into the system to aid the moderator in making a decision on when to terminate the inspection process. Finally, an evaluation of different capture–recapture models is presented, using data collected from software inspection experiments, demonstrating that the approach is viable and can make a contribution to improving performance.     

User‐level operating system transactions

User‐level operating system transactions allow system administrators and ordinary users to perform a sequence of file operations and then commit them as a group, or abort them without leaving any trace behind. Such a facility can aid many system administration and software development tasks. The snapshot isolation concurrency control mechanism allows transactions to be implemented without locking individual system calls; conflicts are detected when the transaction is ready to commit. Along these lines we have implemented a user‐space transaction monitor that is based on ZFS snapshots and a file system event monitor. Transactions are committed through a robust and efficient algorithm that merges the operations performed on a file system's clone back to its parent. Both the performance impact and the implementation cost of the transaction monitor we describe are fairly small. Copyright © 2009 John Wiley & Sons, Ltd.     

Detecting component changes at run time with behavior models

Modern software systems are composed of several services which may be developed and maintained by third parties and thus they can change independently and without notice during the system’s runtime execution. In such systems, changes may possibly be a threat to system functional correctness, and thus to its reliability. Hence, it is important to detect them as soon as they happen to enable proper reaction. Change detection can be done by monitoring system execution and comparing the observed execution traces against models of the services composing the application. Unfortunately, formal specifications for services are not usually provided and developers have to infer them. In this paper we propose a methodology which exactly addresses these issues by using software behavior models to monitor component execution and detect changes. In particular, we describe a technique to infer behavior model specifications with a dynamic black box approach, keep them up-to-date with run time observations and detect behavior changes. Finally, we present a case study to validate the effectiveness of the approach in component change detection for a component that implements a complex, real communication protocol.     

监听软件在网络中的部署

监听软件是网络管理员常用的一项工具,但在实际中经常会碰到监听软件捕获不到数据包的情况,这往往不是软件本身的原因,很多时候是安装部署的问题,该文对监听软件在网络中的几种部署方法进行了阐述.     

基于多源特征空间的微服务可维护性评估

软件企业实践将遗留软件系统解耦成基于微服务架构的系统,以提高系统的可维护性,达到较快市场交付.评估微服务开发阶段的代码可维护性是个关键问题,面临数据多源化、可维护性关注点多样化的难点.通过分析源代码、代码运行轨迹、代码修订历史,本文提出一种多源特征空间模型以统一表示软件多源数据,并基于该模型,从功能性、模块性、可修改性、交互复杂性等关注点度量微服务代码可维护性.据此实现了原型工具MicroEvaluator,并在开源软件上进行了实验验证.     

基于DPDK的高速数据包捕获方法

不断增大的网络带宽给人们提供了丰富的网络应用和服务的同时,也给传统的数据俘获系统带来了挑战.本系统基于Intel数据平面开发套件（Data Plane Development Kit,DPDK）设计了高速网络数据包捕获软件.能够更好适应目前校园网高速网络数据包捕获的要求,为网络数据包分析提供技术支持.最后,本文对基于DPDK的数据包捕获系统和传统Libpcap进行了实验结果对比,表明基于DPDK的数据包捕获系统能够明显提升高速网络出口数据俘获的性能.     

Maintaining the health of software monitors

Software health management (SWHM) techniques complement the rigorous verification and validation processes that are applied to safety-critical systems prior to their deployment. These techniques are used to monitor deployed software in its execution environment, serving as the last line of defense against the effects of a critical fault. SWHM monitors use information from the specification and implementation of the monitored software to detect violations, predict possible failures, and help the system recover from faults. Changes to the monitored software, such as adding new functionality or fixing defects, therefore, have the potential to impact the correctness of both the monitored software and the SWHM monitor. In this work, we describe how the results of a software change impact analysis technique, Directed Incremental Symbolic Execution (DiSE ), can be applied to monitored software to identify the potential impact of the changes on the SWHM monitor software. The results of DiSE can then be used by other analysis techniques, e.g., testing, debugging, to help preserve and improve the integrity of the SWHM monitor as the monitored software evolves.