摘要:

AbstractThe speed of mass storage devices has a significant impact on the performance of computer systems. The speed that is realized on a particular mass storage device, however, depends heavily on how that device is used. Operating systems, such as the UNIXUNIX is a trademark of AT&T Bell Laboratories.time‐sharing system, use layout policies and head‐scheduling disciplines that are designed to work well on average.Numerous studies have shown that disk access patterns exhibit a high degree of locality. Further, studies have shown that these access patterns do not necessarily correspond to the usage patterns anticipated by the system's designers, and that head scheduling is used infrequently enough that it has limited effect. This paper describes the design, implementation, and use of a disk subsystem that adaptively corrects the disparity between expected access patterns and actual access patterns by reorganizing disk data. A representative experiment that demonstrates the resulting performance improvement is presen

ISSN:0038-0644    

DOI:10.1002/spe.4380200302

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractA programming discipline to write abstract data types, iterators and generic modules using the C language is proposed. Program examples are presented making use of features of the ANSI standard for C.The discipline supports object‐oriented development by allowing the programmer to implement abstractions through modules with well‐defined interfaces. To use the abstractions, the programmer is not required to be aware of how they are implemen

ISSN:0038-0644    

DOI:10.1002/spe.4380200303

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractAn experiment of a mechanical code generation for a programmable systolic computer is reported. Two‐dimensional systolic arrays are automatically reduced to one dimension, and code is generated for the one‐dimensional processor array Warp. The technique is demonstrated with two examples: matrix multiplication and LU decomposit

ISSN:0038-0644    

DOI:10.1002/spe.4380200304

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractIn this paper, we present a software system, OPAS (Optimal Allocation System), that incorporates the optimal allocation policy in the analysis of the time‐cost behaviour of parallel computations. OPAS assumes that the underlying system which supports the executions of parallel computations has a finite number of processors, that all the processors have the same speed and that the communication is achieved through a shared memory. OPAS defines the time cost as a function of the input, the algorithm, the data structure, the processor speed, the number of processors and the processing power allocation. In analysing the time cost of a computation, OPAS first uses the optimal allocation policy that we developed previously to determine the amount of processing power each node receives and then derives the computation's time cost. OPAS can evaluate different time‐cost behaviours, such as the minimum time cost, the maximum time cost, the average time cost and the time‐cost variance. It can also determine the speed‐up and efficiency, and plot the time‐cost curve and time‐cost d

ISSN:0038-0644    

DOI:10.1002/spe.4380200305

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper describes a new systematic approach to code generation. The approach is based on an orthogonal model, in which implementation of language‐level operators (‘operators’) and addressing operators (‘operands’) is achieved by two independent subtasks. Each of these phases is specified using a set of decision trees that encode the set of possible implementation templates for each language feature and the set of constraints under which each can be applied. Code selection in each phase is achieved by interpreting these trees using a single comprehensive selection algorithm.The method easily extends to machine independence across a large class of target computers by abstracting the implementation templates into machine‐independent implementation strategies. The selection algorithm is then modified to select between implementation strategies based on a machine capability ‘menu’ that describes each target machine in terms of the subset of implementation strategies for which it has corresponding instruction sequences.The method has been used to implement a prototype machine‐independent code generator for the Concurrent Euclid programming language whose generated code density is consistently within four per cent of production machine‐dependent code generators across its entire target class of fi

ISSN:0038-0644    

DOI:10.1002/spe.4380200306

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractTMS (Text Management System) is a database management system that supports an access method based on both select and search queries. TMS provides support for variable‐length records with pointer fields within the relation. Pointers can be used to support not only text but data from any media, such as graphics and images. An inverted index based on the variable‐length record structure is used for speedy retrieval of records based on keywords. In this paper, the variable length record management of TMS and the keyword‐based retrieval mechanism are desc

ISSN:0038-0644    

DOI:10.1002/spe.4380200307

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380200301

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY