Introduction

The Distributed Real-Time Specification for Java (DRTSJ) is under development within Sun's Java Community Process (JCP) by the membership of the JSR-50 Expert Group (EG). This group, led by the MITRE Corporation, includes representation from individual, academic, U.S. government, defense, and industrial participants.\cite{www:drtsj}

The EG has settled on the following components as a minimum for the final specification:

Distributable Real-Time Threads
a proven programming model for constructing sequential control flow applications with end-to-end timeliness properties in distributed systems. The DRTSJ's distributable threads are supported by a "real-time" implementation of Java's Remote Method Invocation, as originally proposed in JSR-50;
Distributable Thread Integrity Framework
into which application designers may plug appropriate policies for maintaining the health and integrity of distributable threads in the presence of failures; and
Scheduling Framework
into which application designers may plug appropriate user space policies for scheduling distributable and local threads.

News

  • August 2006: DRTSJ status and direction presented to the US Navy Open Architecture (OA) Workshop, Crystal City.
  • August 2006: DRTSJ middleware and Coastal Air Defense Demonstration application presented to US Navy Office of Naval Research at the AWINN final demonstration event at Virginia Tech.
  • 9-11 October 2006: DRTSJ status paper given at JTRES 2006

The JSR-50 Expert Group

Expert Group Representation

Specification Lead E. Douglas Jensen
The MITRE Corporation
jensen@real-time.org
Reference Implementation
Lead
Jonathan S. Anderson
The MITRE Corporation
and Virginia Tech
andersoj@andersoj.org
Reference Implementation
JVM Support
Sunil
Apogee Software, Inc.
Doug Wells
Private Consultant
Raymond K. Clark
The MITRE Corporation

History

  • NIST Real-Time Java Workshop completes work
  • RT-CORBA 1.0
  • RT-CORBA 2.0 (dynamic scheduling)
  • JSR-1: Real-Time Specification for Java v1 -- JSR Accepted
  • JSR-1: RTSJ -- 1.0 Specification Accepted
  • JSR-50: Distributed Real-Time Specification for Java v1 -- JSR Accepted
  • JSR-1: RTSJ -- 1.0.1 Maintenance Specification Accepted
  • RTSJ Reference Implementation released by TimeSys
  • JSR-50: DRTSJ Work Resumes at Virginia Tech with USN ONR funding
  • Apogee RTSJ Implementation (Aphelion) Released
  • Sun RTSJ Implementation Released
  • JSR-282: Real-Time Specification for Java v1.1 -- JSR Accepted

DRTSJ Resources

DRTSJ Publications

  • JSR-50 Specification Request
  • A Rationale for the Distributed Real-Time Specification for Java (Jensen) [pdf]
  • A Framework for Integrating the Real-Time Specification for Java and Java's Remote Method Invocation (Jensen, Clark, Wellings) 2002 [pdf] [bib]
  • 2003 DRTSJ Status Report
  • Distributed Real-Time Specification for Java: A Status Report, JTRES 2006 [paper], presentation [slides]

Related Work

  • JSR-1: The Real-Time Specification for Java [jcp.org] [rtsj.org]
  • JSR-282: The Real-Time Specification for Java v1.1[jcp.org] [rtsj.org]
  • JSR-302: Safety-Critical Java [jcp.org] [rtsj.org]
  • Real-Time CORBA 2.0 (dynamic scheduling) Specification
  • Java Remote Method Invocation (RMI) Specification
  • Apogee Software, Inc: Aphelion RTSJ-compliant JVM

Acknowledgements

The JSR-50 effort has been sponsored in part by the MITRE Corporation, the US Air Force Electronic Systems Center, the US Navy Office of Naval Research through the AWINN grant program, and Virginia Polytechnic and State University. Additionally, Apogee Software has generously donated engineering support for their DRTSJ-compliant Aphelion Real-Time JVM.

Last Updated 3 February 2007, andersojATandersojDOTorg