Coordination languages for parallel programming

Abstract

A number of interesting models have been proposed and used to support coordination languages and systems. In this introductory paper, we first present a number of important concepts that form a context for classification and comparison of various coordination models and languages, and their applications. Next, we review three models and their associated languages, representing three different approaches to coordination. We illustrate the application of each model and language by using it to solve the classical dining philosophers problem. This paper ends with an overview of the rest of the papers that appear in this special issue.

Encapsulating Coordination in the Context of Distributed Systems

“…The coordination model is built of two kinds of entities: the coordinated entities, coordination media, and coordination rules [1]. The coordinated entities are active agents such as processes and passive agents such as shared storage.…”

Coordination of heterogeneous distributed cooperative constraint solving

“…On the other hand, the concept of coordinating a number of activities, such that they can run concurrently in a parallel and distributed fashion, has recently received wide attention [4,5] Due to lack of explicit coordination concepts and constructs, the implementation of BALI does not fully realize its formal model: the treatment of disjunctions and the search are jeopardized and this is not completely satisfactory from a constraint solving point of view. This is mainly due to two causes: (1) the dynamic aspect of the formal model of BALI, and (2) the use of heterogeneous solvers, i.e.…”

“…On the other hand, the concept of coordinating a number of activities, such that they can run concurrently in a parallel and distributed fashion, has recently received wide attention [4,5]. The IWIM model [1,2] (Ideal Worker Ideal Manager) is based on a complete symmetry between and decoupling of producers and consumers, as well as a clear distinction between the computational and the coordination/communication work performed by each process.…”

“…Solver collaboration is a glass-box mechanism which enables one to link black-box tools, i.e., the solvers. BALI allows one to build solver collaborations (solver cooperation [25] and solver combination [17]) by composing component solvers using collaboration primitives (implementing, e.g., sequential, concurrent, and parallel collaboration schemes) and control primitives (such as iterators, fixed-points, and conditionals).On the other hand, the concept of coordinating a number of activities, such that they can run concurrently in a parallel and distributed fashion, has recently received wide attention [4,5] Due to lack of explicit coordination concepts and constructs, the implementation of BALI does not fully realize its formal model: the treatment of disjunctions and the search are jeopardized and this is not completely satisfactory from a constraint solving point of view. This is mainly due to two causes: (1) the dynamic aspect of the formal model of BALI, and (2) the use of heterogeneous solvers, i.e.…”

Real-time programming-in-the-large. The case of monitoring and control systems

“…However, Linda's coordination model is best suited for data-oriented applications [3], that is, applications which are only concerned with what happens to the data. For process-oriented applications (where the temporal ordering of the activities performed by agents is the main concern), Linda's model leads to clumsy specification and the extension of a system turns out to be dangerous and unreliable.…”