检索结果-内蒙古大学图书馆

On the dynamic semantics and the timing behavior of Ravenscar kernels

REAL-TIME SYSTEMS 2005年第1期29卷 59-89页

作者： Vardanega, T Zamorano, J de la Puente, JA Univ Padua Dept Pure & Appl Math I-35100 Padua Italy Tech Univ Dept Comp Architecture Madrid Spain Tech Univ Dept Telemat Engn Madrid Spain

Mature research advances in scheduling theory show that carefully-crafted concurrent computational models permit static analysis of real-time behavior. This evidence enables designers to consider using suitable forms of explicit concurrency to model the inherent concurrency of real-time systems. The Ravenscar Profile, a specifically tailored subset of the Ada 95 tasking model, defines a compact and efficient concurrent computational model, especially suited for the development of high integrity, high efficiency real-time systems. Ravenscar runtimes can be implemented by small, efficient, reliable and certifiable kernels. At least two such implementations already exist and are being industrially deployed. The simplicity and intrinsic determinism of Ravenscar kernels facilitate the definition of metrics that cater for very accurate characterization of the dynamic behavior of the runtime and of the execution time of its primitives. Accurate runtime metrics enable forms of response time analysis that minimize the pessimism in the prediction of the runtime influence on the application. This is especially useful for concurrent systems that exhibit significant dependency on runtime support services. This paper recalls the motivations of the Ravenscar Profile, outlines the definition of it and formulates a precise characterisation of the associated runtime metrics.

关键词： real-time systems concurrent programming tasking restrictions Ravenscar Profile static timing analysis response time analysis

来源：评论

学校读者我要写书评

暂无评论

DHash: Dynamic Hash Tables With Non-Blocking Regular Operations

引用

IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS 2022年第12期33卷 3274-3290页

作者： Wang, Junchang Liu, Dunwei Fu, Xiong Xiao, Fu Tian, Chen Nanjing Univ Posts & Telecommun Sch Comp Sci Nanjing 210023 Peoples R China Nanjing Univ State Key Lab Novel Software Technol Nanjing 210008 Peoples R China

Once started, existing hash tables cannot change their pre-defined hash functions, even if the incoming data cannot be evenly distributed to the hash table buckets. In this paper, we present DHash, a type of hash table for shared memory systems, that can change its hash function and rebuild the hash table on the fly, without noticeably degrading its service. The major technical novelty of DHash stems from an efficient distributing mechanism that can atomically distribute every node when rebuilding, without locking the corresponding hash table buckets. This not only enables non-blocking lookup, insert, and delete operations, but more importantly, makes DHash independent of the implementation of hash table buckets, such that DHash allows programmers to select the set algorithms that meet their requirements best from a variety of existing lock-free and wait-free set algorithms. Evaluations show that DHash can efficiently change its hash function on the fly. Moreover, when rebuilding, DHash consistently outperforms the state-of-the-art hash tables in terms of throughput and response time of concurrent operations, at different concurrency levels, and with different operation mixes and average load factors.

关键词： Hash functions Heuristic algorithms Robustness Kernel Synchronization Linux Time factors concurrent programming parallelism and concurrency dynamic hash tables

来源：评论

学校读者我要写书评

暂无评论

CONJOINING SPECIFICATIONS

引用

ACM TRANSACTIONS ON programming LANGUAGES AND SYSTEMS 1995年第3期17卷 507-534页

作者： ABADI, M LAMPORT, L Digital Equipment Corp. Palo Alto CA

We show how to specify components of concurrent systems. The specification of a system is the conjunction of its components' specifications. Properties of the system are proved by reasoning about its components. We consider both the decomposition of a given system into parts, and the composition of given parts to form a system.

关键词： COMPOSITION concurrent programming DECOMPOSITION LIVENESS PROPERTIES MODULAR SPECIFICATION SAFETY PROPERTIES TEMPORAL LOGIC

来源：评论

学校读者我要写书评

暂无评论

Instant replay debugging of concurrent logic programs

引用

NEW GENERATION COMPUTING 1996年第1期14卷 79-107页

作者： Shen, K Gregory, S Department of Computer Science University of Bristol Bristol U.K.

One problem with debugging (committed choice) concurrent logic programs is that their behaviour may be non-deterministic, in that successive executions of the same program may produce different results. We describe a scheme, based on the 'Instant Replay' scheme developed for more conventional parallel languages, that allows us to reproduce the execution behaviour of a concurrent logic program on subsequent executions, so that the execution may be examined for debugging purposes. The properties of concurrent logic programming languages allow us to simplify our scheme greatly. We have demonstrated our scheme with KLIC, and KL1 on the PIM multiprocessors, but it can also be applied to other committed choice concurrent logic programming languages.

关键词： concurrent programming logic programming debuggings instant replay compile-time analysis abstract interpretation

来源：评论

学校读者我要写书评

暂无评论

SIR: inter-program concurrency support for SR programs

引用

COMPUTER LANGUAGES SYSTEMS & STRUCTURES 2002年第4期28卷 307-325页

作者： Fodor, EF Olsson, RA Univ Calif Davis Dept Comp Sci Davis CA 95616 USA

This paper presents synchronizing interoperable resources (SIR). SIR extends to multi-program environments the concurrent communication mechanisms in the SR concurrent programming language. This paper discusses design and implementation issues including implicit binding, a mechanism for providing seamless concurrent communication. It also examines some performance results of SIR as well as presenting qualitative analysis. This paper also compares SIR with CORBA and other systems that provide interoperability. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： inter-program concurrent programming concurrent programming languages interoperability concurrent programming distributed programming

来源：评论

学校读者我要写书评

暂无评论

USING PARTIAL ORDERS FOR THE EFFICIENT VERIFICATION OF DEADLOCK FREEDOM AND SAFETY PROPERTIES

引用

FORMAL METHODS IN SYSTEM DESIGN 1993年第2期2卷 149-164页

作者： GODEFROID, P WOLPER, P STATE UNIV LIEGE INST MONTEFIOREB-4000 LIEGEBELGIUM

This article presents an algorithm for detecting deadlocks in concurrent finite-state systems without incurring most of the state explosion due to the modeling of concurrency by interleaving. For systems that have a high level of concurrency, our algorithm can be much more efficient than the classical exploration of the whole state space. Finally, we show that our algorithm can also be used for verifying arbitrary safety properties.

关键词： VERIFICATION concurrent programming STATE-SPACE EXPLORATION DEADLOCK DETECTION STATE-SPACE EXPLOSION

来源：评论

学校读者我要写书评

暂无评论

AN SR APPROACH TO MULTIWAY RENDEZVOUS

引用

COMPUTER LANGUAGES 1989年第4期14卷 255-262页

作者： COFFIN, M OLSSON, RA UNIV CALIF DAVIS DIV COMP SCIDAVISCA 95616

This paper presents a new approach to programming multiway rendezvous problems in the SR language. The approach uses SR's concurrent invocation statement and rendezvous mechanism to coordinate the interacting processes. This approach is compared with one that suggested an extension to SR's rendezvous mechanism. The two approaches result in differing program structure. The new approach is shown to lead to simpler and cleaner interfaces between the main process and the worker processes, and uses only existing language mechanisms. The results are of importance to both programmers and designers of concurrent program languages.

关键词： concurrent programming languages concurrent programming Synchronization Multiway rendezvous Rendezvous

来源：评论

学校读者我要写书评

暂无评论

MPI-ACC: Accelerator-Aware MPI for Scientific Applications

引用

IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS 2016年第5期27卷 1401-1414页

作者： Aji, Ashwin M. Panwar, Lokendra S. Ji, Feng Murthy, Karthik Chabbi, Milind Balaji, Pavan Bisset, Keith R. Dinan, James Feng, Wu-chun Mellor-Crummey, John Ma, Xiaosong Thakur, Rajeev Virginia Tech Dept Comp Sci Blacksburg VA 24061 USA N Carolina State Univ Dept Comp Sci Raleigh NC 27695 USA Rice Univ Dept Comp Sci Houston TX USA Argonne Natl Lab Math & Comp Sci Argonne IL 60439 USA Virginia Tech Virginia Bioinformat Inst Blacksburg VA USA

Data movement in high-performance computing systems accelerated by graphics processing units (GPUs) remains a challenging problem. Data communication in popular parallel programming models, such as the Message Passing Interface (MPI), is currently limited to the data stored in the CPU memory space. Auxiliary memory systems, such as GPU memory, are not integrated into such data movement standards, thus providing applications with no direct mechanism to perform end-to-end data movement. We introduce MPI-ACC, an integrated and extensible framework that allows end-to-end data movement in accelerator-based systems. MPI-ACC provides productivity and performance benefits by integrating support for auxiliary memory spaces into MPI. MPI-ACC supports data transfer among CUDA, OpenCL and CPU memory spaces and is extensible to other offload models as well. MPI-ACC's runtime system enables several key optimizations, including pipelining of data transfers, scalable memory management techniques, and balancing of communication based on accelerator and node architecture. MPI-ACC is designed to work concurrently with other GPU workloads with minimum contention. We describe how MPI-ACC can be used to design new communication-computation patterns in scientific applications from domains such as epidemiology simulation and seismology modeling, and we discuss the lessons learned. We present experimental results on a state-of-the-art cluster with hundreds of GPUs;and we compare the performance and productivity of MPI-ACC with MVAPICH, a popular CUDA-aware MPI solution. MPI-ACC encourages programmers to explore novel application-specific optimizations for improved overall cluster utilization.

关键词： Heterogeneous (hybrid) systems parallel systems distributed architectures concurrent programming

来源：评论

学校读者我要写书评

暂无评论

Optimizing memory transactions for large-scale programs

引用

JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING 2016年 89卷 13-24页

作者： Carvalho, Fernando Miguel Cachopo, Joao Univ Lisbon INESC ID Inst Super Tecn P-1699 Lisbon Portugal Polytech Inst Lisbon Inst Super Engn Lisboa ADEETC Lisbon Portugal

Even though Software Transactional Memory (STM) is one of the most promising approaches to simplify concurrent programming, current STM implementations incur significant overheads that render them impractical for many real-sized programs. The key insight of this work is that we do not need to use the same costly barriers for all the memory managed by a real-sized application, if only a small fraction of the memory is under contention lightweight barriers may be used in this case. In this work, we propose a new solution based on an approach of adaptive object metadata (AOM) to promote the use of a fast path to access objects that are not under contention. We show that this approach is able to make the performance of an STM competitive with the best fine-grained lock-based approaches in some of the more challenging benchmarks. (C) 2015 Elsevier Inc. All rights reserved.

关键词： Software Transactional Memory Runtime optimizations concurrent programming

来源：评论

学校读者我要写书评

暂无评论

Loop Optimization for Divergence Reduction on GPUs with SIMT Architecture

引用

IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS 2015年第6期26卷 1633-1642页

作者： Novak, Roman Jozef Stefan Inst Dept Commun Syst SI-1000 Ljubljana Slovenia

The single-instruction multiple thread (SIMT) architecture that can be found in some latest graphical processing units (GPUs) builds on the conventional single-instruction multiple data (SIMD) parallelism while adopting the thread programming model. The architecture suffers from a degraded performance caused by the inefficient divergence handling, a problem hidden by the programmer's view of independent threads. A loop optimization technique having the potential to increase efficiency of the core SIMD block while processing embedded divergences is investigated here. concurrent loops are generally not bound to iterate in lock-step, allowing better alignment of thread flows via iteration scheduling. The concept efficiency is analyzed for fixed and flow-adapting scheduling policies. The proposed payoff model captures loop overhead implications, allowing one to assess the tradeoffs of applying the technique to a specific loop instance. Processing speedups can generally be observed in the total running time if kernels are compute-bound, as demonstrated by several examples. The studied iteration scheduling policies do not impose alterations to the core SIMD concept and design, thus preserving the benefits of data level parallelism.

关键词： concurrent programming efficiency analysis iteration scheduling multithreaded processors optimization SIMT

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：