摘要:

AbstractThe object invocation paradigm is attractive for structuring distributed systems. Distributed object‐based operating systems view the resources of the system as a collection of objects. Object invocation is the primary mechanism in such systems, and is often used as a yardstick for measuring the system performance. However, existing systems of this flavour exhibit poor performance due to the mismatch between the requirements of the object invocation mechanism and the machine architecture. Through measurements of an existing object‐based kernel, we present a breakdown of the costs involved in implementing the object invocation mechanism. The measurements suggest architectural solutions to improve the performance of such systems. We present our preliminary studies towards providing hardware support for the object invocation mechan

ISSN:0038-0644    

DOI:10.1002/spe.4380190902

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

Abstract‘Mount points’ allow more storage to be grafted into tree‐structured hierarchical file systems. Administrative tasks use their locations, which are tabulated in a file. In our System V Unix environment, this file was occasionally removed.Getmntwas written to recover the information.Getmnthas had three significant versions. The original version (getmnt1) was a highly optimized naive tree traversal.Getmnt3improved the real time performance by a mean factor of 7 by pruning unnecessary branches from the traversal.Getmnt3doubledgetmnt2'sspeed, with a change from depth‐first to breadth‐first search. On our development system,getmnt1required 647.6 s to run, whereasgetmnt3require

ISSN:0038-0644    

DOI:10.1002/spe.4380190903

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractA general‐purpose prettyprinting program is presented. The input to the prettyprinter is a linear stream composed of visible symbols and elementary formatting instructions. The user can specify a set of alternative formats and the precedence of the alternatives. The prettyprinter attempts to select automatically the ‘best’ layout that fits on the bounded horizontal space available on the output medium. The prettyprinter is implemented as a library module, which makes it more flexible than many traditional prettyprinters that are written as main programs. For instance, formatted expressions can be mixed with plain text or displayed interactively on the user's terminal, and the application program can use several prettyprinters simultane

ISSN:0038-0644    

DOI:10.1002/spe.4380190904

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractIn this paper we describe an operating system for a workstation designed and implemented by the authors within two and a half years. It includes memory management and module loader, a file system, a viewer system, editors for text and graphics, a compiler, a server interface and various tools. The primary motivation was to demonstrate the feasibility of a small, yet highly flexible and powerful, system, a system that is a (decimal) order of magnitude smaller than commonly used operating systems. This is possible due to regularity of concepts and concentration on the essential. The benefits are not only fewer resources needed, but elegance and generality of concepts resulting in transparency and convenience of use and increased reliability. A corner‐stone of this approach is genuine extensibility, which is achieved by a new language, in particular by a facility called type extension. It allows for the integration of variables (objects) of a new, extended type in structures of elements of an existing base typ

ISSN:0038-0644    

DOI:10.1002/spe.4380190905

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThis paper describes two software tools—a message manager and a map manager—used to implement network protocols. The tools are provided as part of the x‐kernel, an operating system kernel designed to support the construction and composition of protocols. For each tool, we briefly motivate the network task that needs to be done, give a high‐level specification of the tool, outline the algorithms and data structures used to implement the tool and give concrete examples of how the tool is used to implement real protocols. We also demonstrate how the tools, even though they are designed for general use, perform effi

ISSN:0038-0644    

DOI:10.1002/spe.4380190906

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380190901

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY