Research Directions In High Level Parallel Programming Languages

This volume contains most of the papers presented at the workshop on research directions in high-level parallel programming languages, held at Mont Saint-Michel, France, in June 1991. The motivation for organizing this workshop came from the emergence of a new class of formalisms for describing parallel computations in the last few years. Linda, Unity, Gamma, and the Cham are the most significant representatives of this new class. Formalisms of this family promote simple but powerful language features for describing data and programs. These proposals appeared in different contexts and were applied in different domains, and the goal of the workshop was to review the status of this new field and compare experiences. The workshop was organized into four main sessions: Unity, Linda, Gamma, and Parallel Program Design. The corresponding parts ofthe volume are introduced respectively by J. Misra, D. Gelernter, D. Le M tayer, and J.-P. Ban tre.

Programming is hard. Building a large program is like constructing a steam locomotive through a hole the size of a postage stamp. An artefact that is the fruit of hundreds of person-years is only ever seen by anyone through a lOO-line window. In some ways it is astonishing that such large systems work at all. But parallel programming is much, much harder. There are so many more things to go wrong. Debugging is a nightmare. A bug that shows up on one run may never happen when you are looking for it - but unfailingly returns as soon as your attention moves elsewhere. A large fraction of the program's code can be made up of marshalling and coordination algorithms. The core application can easily be obscured by a maze of plumbing. Functional programming is a radical, elegant, high-level attack on the programming problem. Radical, because it dramatically eschews side-effects; elegant, because of its close connection with mathematics; high-level, be cause you can say a lot in one line. But functional programming is definitely not (yet) mainstream. That's the trouble with radical approaches: it's hard for them to break through and become mainstream. But that doesn't make functional programming any less fun, and it has turned out to be a won derful laboratory for rich type systems, automatic garbage collection, object models, and other stuff that has made the jump into the mainstream.

This is the first comprehensive account of this new approach to the fundamentals of parallel programming.

The articles in this volume are revised versions of the best papers presented at the Fifth Workshop on Languages and Compilers for Parallel Computing, held at Yale University, August 1992. The previous workshops in this series were held in Santa Clara (1991), Irvine (1990), Urbana (1989), and Ithaca (1988). As in previous years, a reasonable cross-section of some of the best work in the field is presented. The volume contains 35 papers, mostly by authors working in the U.S. or Canada but also by authors from Austria, Denmark, Israel, Italy, Japan and the U.K.

Parallel processing offers a solution to the problem of providing the processing power necessary to help understand and master the complexity of natural phenomena and engineering structures. By taking several basic processing devices and connecting them together the potential exists of achieving a performance many times that of an individual device. However, building parallel application programs is today recognized as a highly complex activity requiring specialist skills and in-depth knowledge. PARLE is an international, European based conference which focuses on the parallel processing subdomain of informatics and information technology. It is intended to become THE European forum for interchange between experts in the parallel processing domain and to attract both industrial and academic participants with a technical programme designedto provide a balance between theory and practice. This volume contains the proceedings of PARLE '93. The PARLE conference came into existence in 1987 as an initiative from the ESPRIT I programme and the format was revised in 1991/92. PARLE '93 is the second conference with the new format and was held in Munich.

Euro-Parisaninternationalconferencededicatedtothepromotionandadvan- ment of all aspects of parallel computing. The major themes can be divided into the broad categories of hardware, software, algorithms and applications for p- allel computing. The objective of Euro-Par is to provide a forum within which to promote the development of parallel computing both as an industrial te- nique and an academic discipline, extending the frontier of both the state of the art and the state of the practice. This is particularly important at a time when parallel computing is undergoing strong and sustained development and experiencing real industrial take-up. The main audience for and participants in Euro-Parareseenasresearchersinacademicdepartments,governmentlabora- ries and industrial organisations. Euro-Par’s objective is to become the primary choice of such professionals for the presentation of new results in their specic areas. Euro-Par is also interested in applications which demonstrate the e - tiveness of the main Euro-Par themes. There is now a permanent Web site for the series http://brahms. fmi. uni-passau. de/cl/europar where the history of the conference is described. Euro-Par is now sponsored by the Association of Computer Machinery and the International Federation of Information Processing. Euro-Par’99 The format of Euro-Par’99follows that of the past four conferences and consists of a number of topics eachindividually monitored by a committee of four. There were originally 23 topics for this year’s conference. The call for papers attracted 343 submissions of which 188 were accepted. Of the papers accepted, 4 were judged as distinguished, 111 as regular and 73 as short papers.