Language Constructs for Distributed Real-Time Consistency

Loading...
Thumbnail Image
Penn collection
Technical Reports (CIS)
General Robotics, Automation, Sensing and Perception Laboratory
Degree type
Discipline
Subject
GRASP
Funder
Grant number
License
Copyright date
Distributor
Related resources
Author
Contributor
Abstract

In this paper, we present a model and language constructs for a distributed real-time system with the goal of allowing the structured specification of functional and timing constraints, along with explicit, early error recovery from timing faults. To do this, we draw on ideas from (non-distributed) real-time programming and distributed transaction-based systems [81]. A complete language is not specified; the constructs described are assumed to be embedded in a block-structured procedural host programming language such as C [9] or C++ [10] (our current preliminary implementation is in C). The model consists of resources, processes, and a global scheduler. Resources are abstractions that export operations to processes, and specify acceptable concurrency of operations to the scheduler. Processes manipulate resources using the exported operations, and specify synchronization and restrictions on concurrency (at the exported operation level) to the scheduler. Examples of the types of information given to the scheduler are that a set of operations should be performed "simultaneously", or that a sequence of operations should be performed without interference by another process. The global scheduler embodies the entity or entities that schedule the CPU, memory, devices and other resources in the system. It performs preemptive scheduling of all resources based on dynamic priorities associated with the processes, preserves restrictions on concurrency stated by resources and processes, and is capable of giving "guarantees" to processes that they will receive resources during a specified future time interval. The remainder of the paper is structured as follows. In the next section, we present language constructs for an expression of timing constraints called temporal scopes, and described resources and processes. Section 3 describes what is required of the global scheduler to support these constructs, and what is entailed in guaranteeing functional consistency.' We conclude in Section 4.

Advisor
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Publication date
1989-11-27
Volume number
Issue number
Publisher
Publisher DOI
Journal Issue
Comments
University of Pennsylvania Department of Computer and Information Science Technical Report No. MS-CIS-89-78.
Recommended citation
Collection