摘要:

AbstractCode scalability, crucial on any parallel system, determines how well parallel code avoids becoming a bottleneck as its host computer is made larger. The scalability of computer code can be estimated by statistically designed experiments that empirically approximate a multivariate Taylor expansion of the code's execution response function. Each suspected code bottleneck corresponds to a first‐order term in the expansion, the coefficient for that term indicating how sensitive execution is to changes in the suspect location. However, it is the expansion coefficients for second‐order interactions between code segments and the number of processors that are fundamental to discovering which program elements impede parallel speedup. A new, unified view of these second‐order coefficients yields an informal relative scalability test of high utility in code development. Discussion proceeds through actual examples, including a straightforward illustration of the test applied to SLALOM, a complex, multiphase benchmark. A quick graphical shortcut makes the scalability test readily acces

ISSN:0038-0644    

DOI:10.1002/spe.4380251202

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractProgramming languages generally provide a ‘string’ or ‘text’ type to allow manipulation of sequences of characters. This type is usually of crucial importance, since it is normally mentioned in most interfaces between system components. We claim that the traditional implementations of strings, and often the supported functionality, are not well suited to such general‐purpose use. They should be confined to applications with specific, and unusual, performance requirements. We present ‘ropes’ or ‘heavyweight’ strings as an alternative that, in our experience leads to systems that are more robust, both in functionality and in performance.Ropes have been in use in the Cedar environment almost since its inception, but this appears to be neither well‐known, nor discussed in the literature. The algorithms have been gradually refined. We have also recently built a second similar, but somewhat lighter weight, C‐language implementation, which is included in our publically released garbage collector distribution. We describe the algorithms used in both, and give some performance measureme

ISSN:0038-0644    

DOI:10.1002/spe.4380251203

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractOberon simultaneously refers to a moduar, extensible operating system and an object‐oriented programming language developed for its implementation. Although the original Oberon System had been conceived as the native operating system for a custom‐built workstation, furhter implementations for several commercial platforms were developed later and are described here. All of these implementations are based on an efficient, retargetable Oberon compiler, and each provides a complete Oberon environment and the original library interface. This paper describes the structure of the compiler, summarizes the experience gained in adapting it for various CISC and RISC processors, and presents some empirical performance data. It also sheds light on the task of grafting an operating environment onto a variety of existing operating syst

ISSN:0038-0644    

DOI:10.1002/spe.4380251204

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractTemporal message‐flow diagrams (TMFDs), alternatively called sequence charts, interaction diagrams, event traces, or actor diagrams, are illustrations of a system's global message‐passing activity over time, and a pictorial aid to understanding the system's behavior. They are widely used for requirements and documentation for network protocols and object‐oriented applications. We present a general formalism for TMFDs, describe a suite of tools we have designed that employs this formalism, and present our experiences with these tools. The formalism and tools described serve to support and broaden the use of TMFDs in developing communicating sy

ISSN:0038-0644    

DOI:10.1002/spe.4380251205

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380251201

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY