In this paper we describe an implementation of actors in Smalltalk-80, named Actalk. This attempt is designed as a minimal extension preserving the Smalltalk-80 language. Actors are active and autonomous objects, as o...
详细信息
In this paper we describe an implementation of actors in Smalltalk-80, named Actalk. This attempt is designed as a minimal extension preserving the Smalltalk-80 language. Actors are active and autonomous objects, as opposed to standard passive Smalltalk-80 objects. An actor is built from a standard Smalltalk-80 object by associating a process with it and by serializing the messages it could receive into a queue. We will study the cohabitation and synergy between the two models of computations: transfer of active messages (message and thread of activity) between passive objects, and exchange of passive messages between active objects. We propose a sketch of methodology in order to have a safe combination between these two programming paradigms.
Message Driven Computation, derived in part from the parallel object oriented language Actors, provides a more general computational style than strict object orientation, but does include object oriented programming a...
详细信息
Message Driven Computation, derived in part from the parallel object oriented language Actors, provides a more general computational style than strict object orientation, but does include object oriented programming as a special case. Message Driven Computation can also support control-flow, data-flow, and demand-driven computational models. In this article we have embodied MDC in two languages, extensions of Icon and of C. The C version is running multiprocessing on an Encore and multicomputing on an Ncube. In addition to a number of small algorithms, we are running an FP interpreter written in MDC and have an LALR(1) parser generator under construction. We have distributed, parallel garbage collectors for MDC written in an extension of MDC (they have access to the data-structures on a node.)
MITRE - through its Future Generation Computer Architectures program - has conducted research in parallel computing since 1983. Our research is currently directed toward operating systems for massive distributed-memor...
详细信息
MITRE - through its Future Generation Computer Architectures program - has conducted research in parallel computing since 1983. Our research is currently directed toward operating systems for massive distributed-memory MIMDs running general-purpose, object-oriented programs. Scalability and reliability are central concerns in our research. To us, scalability means that a system can be expanded incrementally, and the addition of processors always increases the processing power of the system. Reliability means that application programs continue to run, and run correctly, in spite of isolated hardware failures.
Distributed memory, message passing (DMMP) parallel architectures, such as the intel iPSC(R) computer system, provide the processing power and memory to solve very large parallel programming problems. However, their l...
详细信息
Distributed memory, message passing (DMMP) parallel architectures, such as the intel iPSC(R) computer system, provide the processing power and memory to solve very large parallel programming problems. However, their large grain process model and distributed memory complicate the programmer's view of the system. Extensions have been created for interwork II's global object name space in order to support arrays of objects;interwork II distributes the element objects among the processing nodes so as to balance the number on each node. Indexed objects simplify the programmer's view of parallel architectures by enabling related data to be automatically partitioned among the processing nodes. They also speedup computations by allowing these data to be operated on in parallel. This mechanism has proved useful as the basis for constructing a large, parallel simulation.
The object paradigm has many pleasant properties such as uniformity, factorization and dynamicity. As opposed to the actor paradigm, the object paradigm is greatly lacking with regard to concurrency. The need to exten...
详细信息
The object paradigm has many pleasant properties such as uniformity, factorization and dynamicity. As opposed to the actor paradigm, the object paradigm is greatly lacking with regard to concurrency. The need to extend the semantics of objects to accommodate parallelism has stimulated the proposals of several systems. In particular, investigation of the assumptions that connect objects with parallelism is fruitful. Two different solutions may lead to parallelism: i) objects are mostly passive and processes' execute through' them;ii) parallelism is closely tied to the concept of object. In this paper the Parallel object (PO) proposal is examined, focusing on the aspects related to concurrency. In PO, an object can be an active object (Aobject for short). An Aobject is alone responsible for its own integrity. External activities cannot access private information of an Aobject. Each Aobject decides not only how to respond to any external request, but also when to execute an operation.
A design and verification technique for implementation schemes of distributed software is presented. In this technique, first, the specification is modelled by a concurrentobject system, that is, one which is constit...
详细信息
ISBN:
(纸本)0897912845
A design and verification technique for implementation schemes of distributed software is presented. In this technique, first, the specification is modelled by a concurrentobject system, that is, one which is constituted of computational agents with capability of concurrent execution and message passing. Then, such a concurrentobject system is transformed into another concurrentobject system, which models a sophisticated implementation scheme. Our transformation technique is mainly based on fusing and splitting concurrentobjects. The correctness of transformation rules can be proven formally.
This paper briefly describes how the issues of access to (possibly remote) services and cooperative distributed computing are treated in Guide, a distributed operating system under development at Grenoble. Section 1 i...
详细信息
ISBN:
(纸本)9781450373364
This paper briefly describes how the issues of access to (possibly remote) services and cooperative distributed computing are treated in Guide, a distributed operating system under development at Grenoble. Section 1 is an overview of the project. Section 2 describes the computational model of the system. Section 3 is a discussion of remote computation. Section 4 describes the current implementation status.
Most object-oriented languages are strong on reusability or on strong-typing, but weak on concurrency. In response to this gap, we are developing Hybrid, an object-oriented language in which objects are the active ent...
详细信息
The proceedings contain 43 papers. The topics discussed include: BrouHaHa - a portable Smalltalk interpreter;experience and evolution of concurrent SmallTalk;producer a tool for translating Smalltalk-80 to objective-C...
ISBN:
(纸本)0897912470
The proceedings contain 43 papers. The topics discussed include: BrouHaHa - a portable Smalltalk interpreter;experience and evolution of concurrent SmallTalk;producer a tool for translating Smalltalk-80 to objective-C;INSIST: interactive simulation in Smalltalk;RAPID: prototyping control panel interfaces;Opus: a SmallTalk production system;OTM: applying objects to tasks;some experiments in object-oriented simulation;a pragmatic system for shared persistent objects;use of object-oriented programming in a time series analysis system;composite object support in an object-oriented database system;teaching object-oriented programming with the KEE system;concepts and experiments in computational reflection;delegation is inheritance;class modification in the gemstone object-oriented DBMS;dimensions of object-based language design;an information system based on distributed objects;metaclasses are first class : the ObjVlisp model;using objects to design and build radar ESM systems;experience with CommonLoops;Self: the power of simplicity;modules and type checking in PL/LL;and CLAM - an open system for graphical user interfaces.
暂无评论