检索结果-内蒙古大学图书馆

18th International conference on VLSI design: Power Aware design of VLSI Systems

作者： Bergeron, Janick Synopsys Synopsys's Verification Group

This paper describes how to properly use the object-oriented features of SystemVerilog to model transactions and transactors that execute them. designers, used to a procedural programming model, will learn how to approach a transactor modeling problem using the object-oriented approach. Software engineers, used to a traditional object-oriented programming model, will learn how to adapt their methods to the special requirements of constrained-random verification. This paper will present clear and concise guidelines that can be followed to create effective, easy-to-use and reusable transactor models. Summary: Transactors ? also known as bus-functional models ? have traditionally been modeled using a procedural interface (API). Commands were provided to use every feature available in the transactor. Several commands were often necessary to configure the transactor or to execute the simplest transaction. If the transactor did not provide a feature required by a particular device under test (DUT) or testcase, it had to be modified or rewritten. By using an object-oriented approach for configuration and interfacing, transactors can easily be used out-of-the-box. A few lines are all that is necessary to create valid random stimulus to a DUT or report observed response to a scoreboard. The use of callback methods eliminates the need for a complex and ever-evolving API. Instead of creating yet-another programming language, it leverages the power of SystemVerilog to extend the functionality of a transactor in ways the original author may not have conceived. Without modification, a ransactor can thus be used and reused effectively. Transactors can also be modeled in an extensible fashion. Extensible transactors allow users to define entirely new transactions and commands, should the ones provided by the original implementation prove insufficient. Usability and reusability of transactors does not happen by accident. With careful design and consistent use model, transactors can

关键词： Object oriented programming

来源：评论

学校读者我要写书评

暂无评论

Optimising AspectJ

引用

acm sigplan NOTICES 2005年第6期40卷 117-128页

作者： Avgustinov, P Christensen, AS Hendren, L Kuzins, S Lhoták, J Lhoták, O de Moor, O Sereni, D Sittampalam, G Tibble, J Univ Oxford Programming Tools Grp Oxford OX1 2JD England Univ Aarhus Aarhus Denmark McGill Univ Sable Res Grp Montreal PQ Canada

AspectJ, an aspect-oriented extension of Java, is becoming increasingly popular. However, not much work has been directed at optimising compilers for AspectJ. Optimising AOP languages provides many new and interesting challenges for compiler writers, and this paper identifies and addresses three such challenges. First, compiling around advice efficiently is particularly challenging. We provide a new code generation strategy for around advice, which (unlike previous implementations) both avoids the use of excessive inlining and the use of closures. We show it leads to more compact code, and can also improve run-time performance. Second, woven code sometimes includes run-time tests to determine whether advice should execute. One important case is the cflow pointcut which uses information about the dynamic calling context. Previous techniques for cflow were very costly in terms of both time and space. We present new techniques to minimise or eliminate the overhead of cflow using both intra- and inter-procedural analyses. Third, we have addressed the general problem of how to structure an optimising compiler so that traditional analyses can be easily adapted to the AOP setting. We have implemented all of the techniques in this paper in abc, our AspectBench Compiler for AspectJ, and we demonstrate significant speedups with empirical results. Some of our techniques have already been integrated into the production AspectJ compiler, ajc 1.2.

关键词： AspectJ optimization aspect-oriented programming language cflow pointcut around advice

来源：评论

学校读者我要写书评

暂无评论

An expressive aspect language for system applications with Arachne 05

An expressive aspect language for system applications with A...

引用

AOSD 2005: 4th International conference on Aspect-Oriented Software Development

作者： Douence, Rémi Fritz, Thomas Loriant, Nicolas Menaud, Jean-Marc Ségura-Devillechaise, Marc Südholt, Mario OBASCO Project E ´Cole des Mines de Mantes INRIA 4 rue Alfred Kastler 44307 Nantes Cedex 3 France

ISBN: (纸本)1595930434

C applications, in particular those using operating system level services, frequently comprise multiple crosscutting concerns: network protocols and security are typical examples of such concerns. While these concerns can partially be addressed during design and implementation of an application, they frequently become an issue at runtime, e.g., to avoid server downtime. A deployed network protocol might not be efficient enough and may thus need to be replaced. Buffer overflows might be discovered that imply critical breaches in the security model of an application. A prefetching strategy may be required to enhance performance. While aspect-oriented programming seems attractive in this context, none of the current aspect systems is expressive and efficient enough to address such concerns. This paper presents a new aspect system to provide a solution to this problem. While efficiency considerations have played an important part in the design of the aspect language, the language allows aspects to be expressed more concisely than previous approaches. In particular, it allows aspect programmers to quantify over sequences of execution points as well as over accesses through variable aliases. We show how the former can be used to modularize the replacement of network protocols and the latter to prevent buffer overflows. We also present an implementation of the language as an extension of Arachne, a dynamic weaver for C applications. Finally, we present performance evaluations supporting that Arachne is fast enough to extend high performance applications, such as the Squid web cache. Copyright 2005 acm.

关键词： Software engineering

来源：评论

学校读者我要写书评

暂无评论

X10: An object-oriented approach to non-uniform cluster computing

引用

acm sigplan NOTICES 2005年第10期40卷 519-538页

作者： Charles, P Donawa, C Ebcioglu, K Grothoff, C Kielstra, A von Praun, C Saraswat, V Sarkar, V IBM TJ Watson Res Ctr Yorktown Hts NY 10598 USA Univ Calif Los Angeles Dept Comp Sci Los Angeles CA 90095 USA IBM Toronto Lab Markham ON L6G 1C7 Canada

It is now well established that the device scaling predicted by Moore's Law is no longer a viable option for increasing the clock frequency of future uniprocessor systems at the rate that had been sustained during the last two decades. As a result, future systems are rapidly moving from uniprocessor to multiprocessor configurations, so as to use parallelism instead of frequency scaling as the foundation for increased compute capacity. The dominant emerging multi processor structure for the future is a Non- Uniform Cluster Computing (NUCC) system with nodes that are built out of multi-core SMP chips with non-uniform memory hierarchies, and interconnected in horizontally scalable cluster configurations such as blade servers. Unlike previous generations of hardware evolution, this shift will have a major impact on existing software. Current 00 language facilities for concurrent and distributed programming are inadequate for addressing the needs of NUCC systems because they do not Support the notions of non-uniform data access within a node, or of tight coupling of distributed nodes. We have designed a modern object-oriented programming language, X10, for high performance, high productivity programming of NUCC systems. A member of the partitioned global address space family of languages, X10 highlights the explicit reification of locality in the form of places;lightweight activities embodied in async, future, foreach, and ateach constructs;a construct for termination detection (finish);the use of lock-free synchronization (atomic blocks);and the manipulation of cluster-wide global data structures. We present an overview of the X10 programming model and language, experience with our reference implementation, and results from some initial productivity comparisons between the X10 and JAVA (TM) languages.

关键词： languages performance design X10 Java multithreading non-uniform cluster computing (NUCC) partitioned global address space (PGAS) places data distribution atomic blocks clocks scalability productivity

来源：评论

学校读者我要写书评

暂无评论

Finding application errors and security flaws using PQL: a program query language

引用

acm sigplan NOTICES 2005年第10期40卷 365-383页

作者： Martin, M Livshits, B Lam, MS Stanford Univ Dept Comp Sci Stanford CA 94305 USA

A number of effective error detection tools have been built in recent years to check if a program conforrns to certain design rules. An important class of design rules deals with sequences of events associated with a set of related objects. This paper presents a language called PQL (Program Query language) that allows programmers to express such questions easily in an application-specific context. A query looks like a code excerpt corresponding to the shortest amount of code that would violate a design rule. Details of the target application's precise implementation are abstracted away. The programmer may also specify actions to perform when a match is found, such as recording relevant information or even correcting an erroneous execution on the fly. We have developed both static and dynamic techniques to find solutions to PQL queries. Our static analyzer finds all potential matches conservatively using a context-sensitive, flow-insensitive, inclusion-based pointer alias analysis. Static results are also useful in reducing the number of instrumentation points for dynamic analysis. Our dynamic analyzer instruments the source program to catch all violations precisely as the program runs and to optionally perform user-specified actions. We have implemented the techniques described in this paper and found 206 errors in 6 large real-world open-source Java applications containing a total of nearly 60,000 classes. These errors are important security flaws, resource leaks, and violations of consistency invariants. The combination of static and dynamic analysis proves effective at addressing a wide range of debugging and program comprehension queries. We have found that dynamic analysis is especially suitable for preventing errors such as security vulnerabilities at runtime.

关键词： languages security reliability program traces pattern matching web applications SQL injection resource leaks bug finding

来源：评论

学校读者我要写书评

暂无评论

Pluggable AOP: designing aspect mechanisms for third-party composition 05

Pluggable AOP: designing aspect mechanisms for third-party c...

引用

proceedings of the 20th annual acm sigplan conference on Object-oriented programming, systems, languages, and applications

作者： Sergei Kojarski David H. Lorenz University of Virginia Charlottesville VA

ISBN: (纸本)9781595930316

Studies of Aspect-Oriented programming (AOP) usually focus on a language in which a specific aspect extension is integrated with a base language. languages specified in this manner have a fixed, non-extensible AOP functionality. This paper argues the need for AOP to support the integration and use of multiple domain-specific aspect extensions together. We study the more general case of integrating a base language with a set of third-party aspect extensions for that language. We present a general mixin-based semantic framework for implementing dynamic aspect extensions in such a way that multiple, independently developed aspect mechanisms can be subject to third-party composition and work collaboratively. Principles governing the design of a collaborative aspect mechanism are aspectual effect exposure and implementation hiding.

关键词： aspectual effect aspect mechanism COOL domain-specific aspect language collaboration AOP reuse AspectJ AOP semantics third-party composition mixin aspect extension software components CBSE AOSD AspectWerkz

来源：评论

学校读者我要写书评

暂无评论

Mechanizing the meta-theory of programming languages 05

Mechanizing the meta-theory of programming languages

引用

proceedings of the tenth acm sigplan international conference on Functional programming

作者： Robert Harper Carnegie Mellon University Pittsburgh PA

ISBN: (纸本)9781595930644

What does it mean for a programming language to exist? Usually languages are defined by an informal description augmented by a reference compiler whose behavior is regarded as normative. This approach works well so long as the one true implementation suffices, but as soon as we wish to have multiple compilers for the same language, we must agree on what the language is independently of its implementations. Most often this is accomplished through social processes such as standardization committees for building *** processes have served us well, and will continue to be important for language design. But they are not sufficient to support the level of rigor required to prove theorems about languages and programs written in them. For that we need a semantics, which provides an objective foundation for such analyses, typically in the form of a type system and an operational semantics. But merely having such a rigorous definition for a language is not enough — it must be validated by a body of meta-theory that establishes its coherence and its consistency with *** how are we to develop and maintain this body of theory? For full-scale languages the task is so onerous as to inhibit innovation and foster stagnation. The way forward is to take advantage of the recent advances in mechanized reasoning. By representing a language definition within a logical framework we may subject it to formal analysis, much as we use types to express and enforce crucial invariants in our programs. I will describe our use of the Twelf implementation of the LF logical framework, and discuss our successes and difficulties in using it as a tool for mechanizing the meta-theory of programming languages.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Adding trace matching with free variables to AspectJ 05

Adding trace matching with free variables to AspectJ

引用

proceedings of the 20th annual acm sigplan conference on Object-oriented programming, systems, languages, and applications

作者： Chris Allan Pavel Avgustinov Aske Simon Christensen Laurie Hendren Sascha Kuzins Ondřej Lhoták Oege de Moor Damien Sereni Ganesh Sittampalam Julian Tibble University of Oxford United Kingdom University of Aarhus Denmark McGill University Montreal Canada

ISBN: (纸本)9781595930316

An aspect observes the execution of a base program; when certain actions occur, the aspect runs some extra code of its own. In the AspectJ language, the observations that an aspect can make are confined to the current action: it is not possible to directly observe the history of a ***, there have been several interesting proposals for new history-based language features, most notably by Douence et al. and by Walker and Viggers. In this paper, we present a new history-based language feature called tracematches that enables the programmer to trigger the execution of extra code by specifying a regular pattern of events in a computation trace. We have fully designed and implemented tracematches as a seamless extension of AspectJ.A key innovation in our tracematch approach is the introduction of free variables in the matching patterns. This enhancement enables a whole new class of applications in which events can be matched not only by the event kind, but also by the values associated with the free variables. We provide several examples of applications enabled by this *** introducing and motivating the idea of tracematches via examples, we present a detailed semantics of our language design, and we derive an implementation from that semantics. The implementation has been realised as an extension of the abc compiler for AspectJ.

关键词： program monitoring aspect-oriented programming

来源：评论

学校读者我要写书评

暂无评论

Incrementalization across object abstraction 05

Incrementalization across object abstraction

引用

proceedings of the 20th annual acm sigplan conference on Object-oriented programming, systems, languages, and applications

作者： Yanhong A. Liu Scott D. Stoller Michael Gorbovitski Tom Rothamel Yanni Ellen Liu State University of New York at Stony Brook Stony Brook NY University of Manitoba Winnipeg MB Canada

ISBN: (纸本)9781595930316

Object abstraction supports the separation of what operations are provided by systems and components from how the operations are implemented, and is essential in enabling the construction of complex systems from components. Unfortunately, clear and modular implementations have poor performance when expensive query operations are repeated, while efficient implementations that incrementally maintain these query results are much more difficult to develop and to understand, because the code blows up significantly, and is no longer clear or *** paper describes a powerful and systematic method that first allows the "what" of each component to be specified in a clear and modular fashion and implemented straightforwardly in an object-oriented language; then analyzes the queries and updates, across object abstraction, in the straightforward implementation; and finally derives the sophisticated and efficient "how" of each component by incrementally maintaining the results of repeated expensive queries with respect to updates to their parameters. Our implementation and experimental results for example applications in query optimization, role-based access control, etc. demonstrate the effectiveness and benefit of the method.

关键词： program analysis design invariants program optimization incrementalization object-oriented abstraction program transformation

来源：评论

学校读者我要写书评

暂无评论

Finding application errors and security flaws using PQL: a program query language 05

Finding application errors and security flaws using PQL: a p...

引用

proceedings of the 20th annual acm sigplan conference on Object-oriented programming, systems, languages, and applications

作者： Michael Martin Benjamin Livshits Monica S. Lam Stanford University

ISBN: (纸本)9781595930316

A number of effective error detection tools have been built in recent years to check if a program conforms to certain design rules. An important class of design rules deals with sequences of events asso-ciated with a set of related objects. This paper presents a language called PQL (Program Query language) that allows programmers to express such questions easily in an application-specific context. A query looks like a code excerpt corresponding to the shortest amount of code that would violate a design rule. Details of the tar-get application's precise implementation are abstracted away. The programmer may also specify actions to perform when a match is found, such as recording relevant information or even correcting an erroneous execution on the *** have developed both static and dynamic techniques to find solutions to PQL queries. Our static analyzer finds all potential matches conservatively using a context-sensitive, flow-insensitive, inclusion-based pointer alias analysis. Static results are also use-ful in reducing the number of instrumentation points for dynamic analysis. Our dynamic analyzer instruments the source program to catch all violations precisely as the program runs and to optionally perform user-specified *** have implemented the techniques described in this paper and found 206 errors in 6 large real-world open-source Java applica-tions containing a total of nearly 60,000 classes. These errors are important security flaws, resource leaks, and violations of consis-tency invariants. The combination of static and dynamic analysis proves effective at addressing a wide range of debugging and pro-gram comprehension queries. We have found that dynamic analysis is especially suitable for preventing errors such as security vulner-abilities at runtime.

关键词： bug finding resource leaks pattern matching SQL injection web applications program traces

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：