The papers present in this text survey both distributed shared memory (DSM) efforts and commercial DSM systems. The book discusses relevant issues that make the concept of DSM one of the most attractive approaches for building large-scale, high-performance multiprocessor systems. The authors provide a general introduction to the DSM field as well as a broad survey of the basic DSM concepts, mechanisms, design issues, and systems. The book concentrates on basic DSM algorithms, their enhancements, and their performance evaluation. In addition, it details implementations that employ DSM solutions at the software and the hardware level. This guide is a research and development reference that provides state-of-the art information that will be useful to architects, designers, and programmers of DSM systems.

This is the first book to explain the language Unified Parallel C and its use. Authors El-Ghazawi, Carlson, and Sterling are among the developers of UPC, with close links with the industrial members of the UPC consortium. Their text covers background material on parallel architectures and algorithms, and includes UPC programming case studies. This book represents an invaluable resource for the growing number of UPC users and applications developers. More information about UPC can be found at: http://upc.gwu.edu/ An Instructor Support FTP site is available from the Wiley editorial department.

Abstract: "The C Region Library (CRL) is a new all-software distributed shared memory (DSM) system. CRL requires no special compiler, hardware, or operating system support beyond the ability to send and receive messages between processing nodes. It provides a simple, portable, region-based shared address space programming model that is capable of delivering good performance on a wide range of multiprocessor and distributed system architectures. Each region is an arbitrarily sized, contiguous area of memory. The programmer defines regions and delimits accesses to them using annotations. CRL implementations have been developed for two platforms: the Thinking Machines CM-5, a commercial multicomputer, and the MIT Alewife machine, an experimental multiprocessor offering efficient hardware support for both message passing and shared memory. Results are presented for up to 128 processors on the CM-5 and up to 32 processors on Alewife. Using Alewife as a vehicle, this thesis presents results from the first completely controlled comparison of scalable hardware and software DSM systems. These results indicate that CRL is capable of delivering performance that is competitive with hardware DSM systems: CRL achieves speedups within 15% of those provided by Alewife's native hardware-supported shared memory, even for challenging applications (e.g., Barnes-Hut) and small problem sizes. A second set of experimental results provides insight into the sensitivity of CRL's performance to increased communication costs (both higher latency and lower bandwidth). These results demonstrate that even for relatively challenging applications, CRL should be capable of delivering reasonable performance on current-generation distributed systems. Taken together, these results indicate the substantial promise of CRL and other all- software approaches to providing shared memory functionality and suggest that in many cases special-purpose hardware support for shared memory may not be necessary."