检索结果-内蒙古大学图书馆

Implicit Invocation Meets Safe, Implicit Concurrency

acm sigplan NOTICES 2011年第2期46卷 63-72页

作者： Long, Yuheng Mooney, Sean L. Sondag, Tyler Rajan, Hridesh Iowa State Univ Dept Comp Sci Ames IA 50011 USA

Writing correct and efficient concurrent programs still remains a challenge. Explicit concurrency is difficult, error prone, and creates code which is hard to maintain and debug. this type of concurrency also treats modular program design and concurrency as separate goals, where modularity often suffers. To solve these problems, we are designing a new language that we call Panini. In this paper, we focus on Panini's asynchronous, typed events which reconcile the modularity goal promoted by the implicit invocation design style with the concurrency goal of exposing potential concurrency between the execution of subjects and observers. Since modularity is improved and concurrency is implicit in Panini, programs are easier to reason about and maintain. the language incorporates a static analysis to determine potential conflicts between handlers and a dynamic analysis which uses the conflict information to determine a safe order for handler invocation. this mechanism avoids races and deadlocks entirely, yielding programs with a guaranteed deterministic semantics. To evaluate our language design and implementation we show several examples of its usage as well as an empirical study of program performance. We found that not only is developing and understanding Panini programs significantly easier compared to standard concurrent object-oriented programs, but also performance of Panini programs is comparable to their equivalent hand-tuned versions written using Java's fork-join framework.

关键词： languages design Performance Safe Implicit Concurrency Modularity

来源：评论

学校读者我要写书评

暂无评论

Laws of concurrent programming 14

Laws of concurrent programming

引用

Proceedings of the 35th acm sigplan conference on programming language design and implementation

作者： Tony Hoare Microsoft Research Cambridge United Kingdom

ISBN: (纸本)9781450327848

the talk extends the Laws of programming [1] by four laws governing concurrent composition of programs. this operator is associative and commutative and distributive through union; and it has the same unit (do nothing) as sequential composition. Furthermore, sequential and concurrent composition distribute through each other, in accordance with an exchange law; this permits an implementation of concurrency by partial interleaving.

关键词： separation logic CCS verification concurrency

来源：评论

学校读者我要写书评

暂无评论

End-to-End Verification of Information-Flow Security for C and Assembly Programs

引用

acm sigplan NOTICES 2016年第6期51卷 648-664页

作者： Costanzo, David Shao, Zhong Gu, Ronghui Yale Univ New Haven CT 06520 USA

Protecting the confidentiality of information manipulated by a computing system is one of the most important challenges facing today's cybersecurity community. A promising step toward conquering this challenge is to formally verify that the end-to-end behavior of the computing system really satisfies various information-flow policies. Unfortunately, because today's system software still consists of both C and assembly programs, the end-to-end verification necessarily requires that we not only prove the security properties of individual components, but also carefully preserve these properties through compilation and cross-language linking. In this paper, we present a novel methodology for formally verifying end-to-end security of a software system that consists of both C and assembly programs. We introduce a general definition of observation function that unifies the concepts of policy specification, state indistinguishability, and whole-execution behaviors. We show how to use different observation functions for different levels of abstraction, and how to link different security proofs across abstraction levels using a special kind of simulation that is guaranteed to preserve state indistinguishability. To demonstrate the effectiveness of our new methodology, we have successfully constructed an end-to-end security proof, fully formalized in the Coq proof assistant, of a nontrivial operating system kernel (running on an extended CompCert x86 assembly machine model). Some parts of the kernel are written in C and some are written in assembly;we verify all of the code, regardless of language.

关键词： Verification Security Reliability languages design Information Flow Control Security Policy Specification Security-Preserving Simulation Program Verification Certified OS Kernels

来源：评论

学校读者我要写书评

暂无评论

A design and Verification Methodology for Secure Isolated Regions

引用

acm sigplan NOTICES 2016年第6期51卷 665-681页

作者： Sinha, Rohit Costa, Manuel Lal, Akash Lopes, Nuno P. Rajamani, Sriram Seshia, Sanjit A. Vaswani, Kapil Univ Calif Berkeley Berkeley CA 94720 USA Microsoft Res London England Microsoft Res Bengaluru Karnataka India

Hardware support for isolated execution (such as Intel SGX) enables development of applications that keep their code and data confidential even while running on a hostile or compromised host. However, automatically verifying that such applications satisfy confidentiality remains challenging. We present a methodology for designing such applications in a way that enables certifying their confidentiality. Our methodology consists of forcing the application to communicate with the external world through a narrow interface, compiling it with runtime checks that aid verification, and linking it with a small runtime library that implements the interface. the runtime library includes core services such as secure communication channels and memory management. We formalize this restriction on the application as Information Release Confinement (IRC), and we show that it allows us to decompose the task of proving confidentiality into (a) one-time, human-assisted functional verification of the runtime to ensure that it does not leak secrets, (b) automatic verification of the application's machine code to ensure that it satisfies IRC and does not directly read or corrupt the runtime's internal state. We present/CONFIDENTIAL: a verifier for IRC that is modular, automatic, and keeps our compiler out of the trusted computing base. Our evaluation suggests that the methodology scales to real-world applications.

关键词： Enclave Programs Secure Computation Confidentiality Formal Verification

来源：评论

学校读者我要写书评

暂无评论

Merge: A programming model for heterogeneous multi-core systems

引用

acm sigplan NOTICES 2008年第3期43卷 287-296页

作者： Linderman, Michael D. Collins, Jamison D. Wang, Hong Meng, Teresa H. Stanford Univ Dept Elect Engn Stanford CA 94305 USA Intel Corp Microarchitecture Res Lab Santa Cruz CA USA

In this paper we propose the Merge framework, a general purpose programming model for heterogeneous multi-core systems. the Merge framework replaces current ad hoc approaches to parallel programming on heterogeneous platforms with a rigorous, library-based methodology that can automatically distribute computation across heterogeneous cores to achieve increased energy and performance efficiency. the Merge framework provides (1) a predicate dispatch-based library system for managing and invoking function variants for multiple architectures;(2) a high-level, library-oriented parallel language based on map-reduce;and (3) a compiler and runtime which implement the map-reduce language pattern by dynamically selecting the best available function implementations for a given input and machine configuration. Using a generic sequencer architecture interface for heterogeneous accelerators, the Merge framework can integrate function variants for specialized accelerators, offering the potential for to-the-metal performance for a wide range of heterogeneous architectures, all transparent to the user. the Merge framework has been prototyped on a heterogeneous platform consisting of an Intel Core 2 Duo CPU and an 8-core 32-thread Intel Graphics and Media Accelerator X3000, and a homogeneous 32-way Unisys SNIP system with Intel Xeon processors. We implemented a set of benchmarks using the Merge framework and enhanced the library with X3000 specific implementations, achieving speedups of 3.6x - 8.5x using the X3000 and 5.2x - 22x using the 32-way system relative to the straight C reference implementation on a single IA32 core.

关键词： performance design languages heterogeneous multi-core GPGPU predicate dispatch

来源：评论

学校读者我要写书评

暂无评论

Input Responsiveness: Using Canary Inputs to Dynamically Steer Approximation

引用

acm sigplan NOTICES 2016年第6期51卷 161-176页

作者： Laurenzano, Michael A. Hill, Parker Samadi, Mehrzad Mahlke, Scott Mars, Jason Tang, Lingjia Univ Michigan Dept Elect Engn & Comp Sci Ann Arbor MI 48109 USA

this paper introduces Input Responsive Approximation ( IRA), an approach that uses a canary input - a small program input carefully constructed to capture the intrinsic properties of the original input - to automatically control how program approximation is applied on an input-by-input basis. Motivating this approach is the observation that many of the prior techniques focusing on choosing how to approximate arrive at conservative decisions by discounting substantial differences between inputs when applying approximation. the main challenges in overcoming this limitation lie in making the choice of how to approximate both effectively (e.g., the fastest approximation that meets a particular accuracy target) and rapidly for every input. With IRA, each time the approximate program is run, a canary input is constructed and used dynamically to quickly test a spectrum of approximation alternatives. Based on these runtime tests, the approximation that best fits the desired accuracy constraints is selected and applied to the full input to produce an approximate result. We use IRA to select and parameterize mixes of four approximation techniques from the literature for a range of 13 image processing, machine learning, and data mining applications. Our results demonstrate that IRA significantly outperforms prior approaches, delivering an average of 10.2x speedup over exact execution while minimizing accuracy losses in program outputs.

关键词： Performance Runtime Systems Compilers Approximate Computing Performance Experimentation design

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

Work In Progress: Computer design for Intermediate-Level Digital Systems Course

Work In Progress: Computer Design for Intermediate-Level Dig...

引用

Frontiers in Education (FIE) conference

作者： Bryan J. Mealy Electrical Engineering Department Computer Engineering Program California Polytechnic State University San Louis Obispo CA USA

the flexibility of programmable logic devices (PLDs) and their supporting CAD (computer aided design) tools make PLDs ideal for digital systems design courses. this paper outlines a computer design-based course and supporting laboratory targeted for students with intermediate-level digital design skills. the unifying theme of this course is the design, implementation, and programming of a relatively complex microcontroller (MCU). this course emphasizes the development and subsequent integration of basic individual computer building blocks using a hardware description language (HDL). the major topics in the course include finite state machine (FSM) design, computer system architecture, and assembly language programming. Placing emphasis on a hierarchical design approach and ensuring continuity in the course topics reduces potential difficulties in presenting this scope of topics

关键词： Digital systems Hardware design languages Assembly Microcontrollers Computer architecture Digital circuits Programmable logic devices design automation Laboratories Automata

来源：评论

学校读者我要写书评

暂无评论

A dynamic optimization framework for a Java just-in-time compiler 01

A dynamic optimization framework for a Java just-in-time com...

引用

acm sigplan conference on Object-oriented programming, Systems, languages, and Applications

作者： Toshio Suganuma Toshiaki Yasue Motohiro Kawahito Hideaki Komatsu Toshio Nakatani IBM Tokyo Research Laboratory 1623-14 Shimoturuma Yamato-shi Kanagawa 242-8502 Japan

ISBN: (纸本)1581133359

the high performance implementation of Java Virtual Machines (JVM) and just-in-time (JIT) compilers is directed toward adaptive compilation optimizations on the basis of online runtime profile information. this paper describes the design and implementation of a dynamic optimization framework in a production-level Java JIT compiler. Our approach is to employ a mixed mode interpreter and a three level optimizing compiler, supporting quick, full, and special optimization, each of which has a different set of tradeoffs between compilation overhead and execution speed. a lightweight sampling profiler operates continuously during the entire program's exectuion. When necessary, detailed information on runtime behavior is collected by dynmiacally generating instrumentation code which can be installed to and uninstalled from the specified recompilation target code. Value profiling with this instrumentation mechanism allows fully automatic code specialization to be performed on the basis of specific parameter values or global data at the highest optimization level. the experimental results show that our approach offers high performance and a low code expansion ratio in both program startup and steady state measurements in comparison to the compile-only approach, and that the code specialization can also contribute modest performance improvement

关键词： just in time compiler Java Java programming language HIGH-PERFORMANCE tradeoffs performance boost Runtime Codes Collected papers

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

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：