摘要:

AbstractIn an empirical case study of software tools, two participants used the ITS style designer's language to implement a general purpose, executable, rule‐based user interface style. This language allows style designers to select, combine and modify rule prototypes in order to construct a rule‐based user interface style. The participants implemented the entire IBM CUA‐2 user interface style, plus nine additional human‐computer interaction techniques, in 5–7 person‐weeks. This is impressive productivity. Typically the time to complete asingleCUA‐2 application is measured in person‐years, not person‐weeks. The style implemented here is reusable by any ITS‐implemented application. The achievement reported here shows that about half the work ofallITS‐implemented CUA‐2 applications has been completed in a few person‐weeks. This result demonstrates the power and productivity of the ITS approach and tools. The results of this case study showed that key ‘ready‐mades’ (e.g. named attribute groups) provided in the style designer's toolkit could be used intact, which is important for importing or exporting interaction techniques from one style to another style. The results generalize to other computer‐literate designers who may want to use these tools to c

ISSN:0038-0644    

DOI:10.1002/spe.4380211202

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper describes a general‐purpose file system that uses a write‐once‐read‐many (WORM) optical disk accessed via a magnetic disk cache. The cache enables blocks to be modified a number of times before they are written to the WORM and increases performance. Snapshots of the file system can be made at any time without limiting the users' access to files. These snapshots reside entirely on the WORM, are accessible to the user via a second read‐only file system, do not contain multiple copies of unchanged data, and can be used to rebuild the file system in the event that the disk cache is destroyed. The file system has been implemented as part of Plan 9, an experimental operating system under development at AT&T Bell Lab

ISSN:0038-0644    

DOI:10.1002/spe.4380211203

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper describes the design and implementation of an optimizing compiler that automatically generates profile information to assist classic code optimizations. This compiler contains two new components, an execution profiler and a profile‐based code optimizer, which are not commonly found in traditional optimizing compilers. The execution profiler inserts probes into the input program, executes the input program for several inputs, accumulates profile information and supplies this information to the optimizer. The profile‐based code optimizer uses the profile information to expose new optimization opportunities that are not visible to traditional global optimization methods. Experimental results show that the profile‐based code optimizer significantly improves the performance of production C programs that have already been optimized by a high‐quality global code op

ISSN:0038-0644    

DOI:10.1002/spe.4380211204

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractConcurrency is an attractive method for reducing the execution time of compilers. By dividing source programs into segments which can be compiled concurrently, the task of compiling programs can be accelerated.Many of the difficult problems which arise when constructing a concurrent compiler occur in the implementation of the semantic analyser. This paper investigates the problems involved in designing the semantic analyser for a concurrent compiler for a modern, block‐structured language. Several approaches to solving the problems which arise are presented. These solutions are then implemented as part of a concurrent Modula‐2 + compiler, running on a shared memory multiprocessor. A performance evaluation of these semantic analysers is presen

ISSN:0038-0644    

DOI:10.1002/spe.4380211205

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThis paper presents lessons learned from an experiment to reverse engineer a program. A reverse engineering process was used as part of a project to develop an Ada implementation of a Fortran program and upgrade the existing documentation. To accomplish this, design information was extracted from the Fortran source code and entered into a software development environment. The extracted design information was used to implement a new version of the program written in Ada. This experiment revealed issues about recovering design information, such as, separating design details from implementation details, dealing with incomplete or erroneous information, traceability of information between implementation and recovered design, and re‐engineering. The reverse engineering process used to recover the design, and the experience gained during the study are reporte

ISSN:0038-0644    

DOI:10.1002/spe.4380211206

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe Homogeneous Multiprocessor (HM) has a linear‐array topology, with interprocessor communications achieved by the sharing of memory between nearest neighbours, by adjacent‐processor signalling, and through a high‐speed network (the H‐Network). The operating system nucleus (the HM‐Nucleus) for the HM contains a communications subsystem that provides low‐overhead communications, both for user processes and for the rest of the HM‐Nucleus, using the shared memory, the signalling capability, and the H‐Network.The design for the communications subsystem provides uniformity of access to the three mechanisms by following the IEEE 802.2/802.3 LLC/MAC specifications. Flexibility of access is achieved by adopting the STREAMS facility from System V UNIX.A new implementation of STREAMS has been built using Turing Plus for both the programming and the simulation/testing, with no need to access the actual hardware until final test. Completion of the STREAMS framework has made it possible subsequently to code an 802.2 LLC module and an 802.3‐based shared memory driver very quickly.The STREAMS framework has also made it feasible to cast some algorithms used by other parts of the HM‐Nucleus as protocols, and implement them as STREAMS modules, resulting in considerable simplification in the design process. Since the framework was designed to be completely independent of the host processor, it provides a very general vehicle for p

ISSN:0038-0644    

DOI:10.1002/spe.4380211207

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0038-0644    

DOI:10.1002/spe.4380211201

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY