Submicron Systems Architecture Project: Semiannual Technial Report

No abstract available

Performance measurement and analysis of PC based cluster server using SET of Architecture and modeling a scalable High performance cluster

Not availabl

ProperCAD II: A Run-Time Library for Portable, Parallel, Object-Oriented Programming with Applications to VLSI CAD

Coordinated Science Laboratory was formerly known as Control Systems LaboratorySemiconductor Research Corporation / grant 93-DP-10

Objects in Oz

The programming language Oz integrates the paradigms of imperative, functional and concurrent constraint programming in a computational framework of unprecedented breadth, featuring stateful programming through cells, lexically scoped higher-order programming, and explicit concurrency synchronized by logic variables. Object-oriented programming is another paradigm that provides a set of concepts useful in software practice. In this thesis we address the question how object-oriented programming can be suitably supported in Oz. As a lexically scoped higher-order language, Oz can express a wide range of object-oriented concepts. We present a simple yet expressive object system, demonstrate its usability and outline an efficient implementation. A central aspect of Oz is its support for concurrent computation. We examine the impact of concurrency on the design of an object system and explore the use of objects in concurrent programming.Die Programmiersprache Oz verbindet die Paradigmen der imperativen, funktionalen und nebenläufigen Constraint-Programmierung in einem kohärenten Berechnungsmodell. Oz unterstützt zustandsbehaftete Programmierung, Programmierung höherer Ordnung mit lexikalischer Bindung und explizite Nebenläufigkeit, die mithilfe logischer Variablen synchroniziert werden kann. In der Softwarepraxis hat sich mit der objekt-orientierten Programmierung ein weiteres Programmierparadigma etabliert. In der vorliegenden Arbeit beschäftige ich mich mit der Frage, wie objekt-orientierte Programmierung in geeigneter Weise in Oz unterstützt werden kann. Ich stelle ein einfaches und doch ausdrucksstarkes Objektsystem vor, belege seine Benutzbarkeit und umreiße seine effiziente Implementierung. Ein zentraler Aspekt der Programmiersprache Oz ist ihre Unterstützung nebenläufiger Berechnung. Infolgedessen nimmt die Untersuchung des Ein- flusses der Nebenläufigkeit auf das Design des Objektsystems einen besonderen Rang ein. Ich untersuche die Möglichkeiten, die das Objektsystem bietet, um nebenläufige objekt-orientierte Programmiertechniken auszudrücken

High-performance all-software distributed shared memory

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1996.Includes bibliographical references (p. 165-172).by Kirk Lauritz Johnson.Ph.D

Dynamic computation migration in distributed shared memory systems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1995.Vita.Includes bibliographical references (p. 123-131).by Wilson Cheng-Yi Hsieh.Ph.D

A parallel functional language compiler for message-passing multicomputers

The research presented in this thesis is about the design and implementation of Naira, a parallel, parallelising compiler for a rich, purely functional programming language. The source language of the compiler is a subset of Haskell 1.2. The front end of Naira is written entirely in the Haskell subset being compiled. Naira has been successfully parallelised and it is the largest successfully parallelised Haskell program having achieved good absolute speedups on a network of SUN workstations. Having the same basic structure as other production compilers of functional languages, Naira's parallelisation technology should carry forward to other functional language compilers. The back end of Naira is written in C and generates parallel code in the C language which is envisioned to be run on distributed-memory machines. The code generator is based on a novel compilation scheme specified using a restricted form of Milner's 7r-calculus which achieves asynchronous communication. We present the first working implementation of this scheme on distributed-memory message-passing multicomputers with split-phase transactions. Simulated assessment of the generated parallel code indicates good parallel behaviour. Parallelism is introduced using explicit, advisory user annotations in the source' program and there are two major aspects of the use of annotations in the compiler. First, the front end of the compiler is parallelised so as to improve its efficiency at compilation time when it is compiling input programs. Secondly, the input programs to the compiler can themselves contain annotations based on which the compiler generates the multi-threaded parallel code. These, therefore, make Naira, unusually and uniquely, both a parallel and a parallelising compiler. We adopt a medium-grained approach to granularity where function applications form the unit of parallelism and load distribution. We have experimented with two different task distribution strategies, deterministic and random, and have also experimented with thread-based and quantum- based scheduling policies. Our experiments show that there is little efficiency difference for regular programs but the quantum-based scheduler is the best in programs with irregular parallelism. The compiler has been successfully built, parallelised and assessed using both idealised and realistic measurement tools: we obtained significant compilation speed-ups on a variety of simulated parallel architectures. The simulated results are supported by the best results obtained on real hardware for such a large program: we measured an absolute speedup of 2.5 on a network of 5 SUN workstations. The compiler has also been shown to have good parallelising potential, based on popular test programs. Results of assessing Naira's generated unoptimised parallel code are comparable to those produced by other successful parallel implementation projects

Adaptive object management for distributed systems

This thesis describes an architecture supporting the management of pluggable software components and evaluates it against the requirement for an enterprise integration platform for the manufacturing and petrochemical industries. In a distributed environment, we need mechanisms to manage objects and their interactions. At the least, we must be able to create objects in different processes on different nodes; we must be able to link them together so that they can pass messages to each other across the network; and we must deliver their messages in a timely and reliable manner. Object based environments which support these services already exist, for example ANSAware(ANSA, 1989), DEC's Objectbroker(ACA,1992), Iona's Orbix(Orbix,1994)Yet such environments provide limited support for composing applications from pluggable components. Pluggability is the ability to install and configure a component into an environment dynamically when the component is used, without specifying static dependencies between components when they are produced. Pluggability is supported to a degree by dynamic binding. Components may be programmed to import references to other components and to explore their interfaces at runtime, without using static type dependencies. Yet thus overloads the component with the responsibility to explore bindings. What is still generally missing is an efficient general-purpose binding model for managing bindings between independently produced components. In addition, existing environments provide no clear strategy for dealing with fine grained objects. The overhead of runtime binding and remote messaging will severely reduce performance where there are a lot of objects with complex patterns of interaction. We need an adaptive approach to managing configurations of pluggable components according to the needs and constraints of the environment. Management is made difficult by embedding bindings in component implementations and by relying on strong typing as the only means of verifying and validating bindings. To solve these problems we have built a set of configuration tools on top of an existing distributed support environment. Specification tools facilitate the construction of independent pluggable components. Visual composition tools facilitate the configuration of components into applications and the verification of composite behaviours. A configuration model is constructed which maintains the environmental state. Adaptive management is made possible by changing the management policy according to this state. Such policy changes affect the location of objects, their bindings, and the choice of messaging system

Polyhedral+Dataflow Graphs

This research presents an intermediate compiler representation that is designed for optimization, and emphasizes the temporary storage requirements and execution schedule of a given computation to guide optimization decisions. The representation is expressed as a dataflow graph that describes computational statements and data mappings within the polyhedral compilation model. The targeted applications include both the regular and irregular scientific domains. The intermediate representation can be integrated into existing compiler infrastructures. A specification language implemented as a domain specific language in C++ describes the graph components and the transformations that can be applied. The visual representation allows users to reason about optimizations. Graph variants can be translated into source code or other representation. The language, intermediate representation, and associated transformations have been applied to improve the performance of differential equation solvers, or sparse matrix operations, tensor decomposition, and structured multigrid methods