The 1987 Princeton Workshop on Algorithm, Architecture and Technology Issues for Models of Concurrent Computation was organized as an interdisciplinary work shop emphasizing current research directions toward concurrent computing systems. With participants from several different fields of specialization, the workshop cov ered a wide variety of topics, though by no means a complete cross section of issues in this rapidly moving field. The papers included in this book were prepared for the workshop and, taken together, provide a view of the broad range of issues and alternative directions being explored. To organize the various papers, the book has been divided into five parts. Part I considers new technology directions. Part II emphasizes underlying theoretical issues. Communication issues, which are ad dressed in the majority of papers, are specifically highlighted in Part III. Part IV includes papers stressing the fault tolerance and reliability of systems. Finally, Part V includes systems-oriented papers, where the system ranges from VLSI circuits through powerful parallel computers. Much of the initial planning of the workshop was completed through an informal AT&T Bell Laboratories group consisting of Mehdi Hatamian, Vijay Kumar, Adri aan Ligtenberg, Sailesh Rao, P. Subrahmanyam and myself. We are grateful to Stuart Schwartz, both for the support of Princeton University and for his orga nizing local arrangements for the workshop, and to the members of the organizing committee, whose recommendations for participants and discussion topics were par ticularly helpful. A. Rosenberg, and A. T.

The foundations of parallel computation, especially the efficiency of computation, are the concern of this book. Distinguished international researchers have contributed fifteen chapters which together form a coherent stream taking the reader who has little prior knowledge of the field to a position of being familiar with leading edge issues. The book may also function as a source of teaching material and reference for researchers. The first part is devoted to the Parallel Random Access Machine (P-RAM) model of parallel computation. The initial chapters justify and define the model, which is then used for the development of algorithm design in a variety of application areas such as deterministic algorithms, randomisation and algorithm resilience. The second part deals with distributed memory models of computation. The question of efficiently implementing P-RAM algorithms within these models is addressed as are the immensely interesting prospects for general purpose parallel computation.

Illustrating the effect of concurrency on programs written in familiar languages, this text focuses on novel language abstractions that truly bring concurrency into the language and aid analysis and compilation tools in generating efficient, correct programs. It also explains the complexity involved in taking advantage of concurrency with regard to program correctness and performance. The book describes the historical development of current programming languages and the common threads that exist among them. It also contains several chapters on design patterns for parallel programming and includes quick reference guides to OpenMP, Erlang, and Cilk. Ancillary materials are available on the book's website.

This volume constitutes the proceedings of the Fifth International Conference on Concurrency Theory, CONCUR '94, held at Uppsala, Sweden in August 1994. In total, 29 refereed research papers selected from 108 submissions for the conference are presented together with full papers or abstracts of the 5 invited talks by prominent speakers. The book contains recent results on all relevant aspects of concurrency research and thus competently documents the progress of the field since the predecessor conference CONCUR '93, the proceedings of which are published as LNCS 715.

The transition from sequential to parallel computation is an area of critical concern in today's computer technology, particularly in architecture, programming languages, systems, and artificial intelligence. This book addresses central issues in concurrency, and by producing both a syntactic definition and a denotational model of Hewitt's actor paradigm—a model of computation specifically aimed at constructing and analyzing distributed large-scale parallel systems—it substantially advances the understanding of parallel computation. Contents Introduction • General Design Decisions • Computation in ACTOR Systems • A More Expressive Language • A Model for ACTOR Systems • Concurrency Issues • Abstraction and Compositionality • Conclusions