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Research in Real-Time Systems at UNC

Research in Real-Time Systems at UNC

Real-time systems are loosely defined as the class of computer systems that interact with the external world in a time frame defined by the external world. Research at UNC in real-time systems spans programming languages, operating systems, distributed systems, and scheduling theory. This research is carried out by the Distributed and Real-Time Systems (DiRT) research group.

Much of our present work focuses on single and multiprocesor real-time operating systems. Our group has previously developed a real-time operating system kernel, YARTOS (Yet Another Real-Time Operating System), that has been used to further research in real-time multimedia systems. Current work is on the use of proportional share resource allocation technology for providing real-time services in general purpose operating systems and on the use of wait-free and lock-free synchronization technology for accessing shared objects in real-time.

For more information, please contact either one of the students or faculty members listed below. Better yet, scan the abstract from our latest paper or two.

Current Projects & Students

  • Adaptive, rate-based scheduling — Steve Goddard
  • Proportional share resource allocation in general purpose operating systems — Gerardo Lamastra
  • Pfair multiprocessor real-time scheduling — Anand Srinivasan
  • Real-time network connection scheduling — Alex Blate
  • Real-time data-flow for signal processing — Steve Goddard

Faculty

Related Research Projects at UNC

Selected Papers (Listed in reverse chronological order)

(Click here for an alphabetical listing of all papers stored on-line, or a list papers on-line sorted by publication venue (conference/journal). Also, copies of slides for talks about some of these papers are available on-line. Click here for a list.)

Co-Scheduling Variable Execution Time Requirement Real-time Tasks and Non-Real-Time Tasks

ECRTS, 2007Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Managing Latency and Buffer Requirements in Processing Graph Chains

The Computer Journal, 2001Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Rate-Based Resource Allocation Models for Embedded Systems

EMSOFT 2001: Workshop on Embedded Software, October 2001.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.(A copy of the slides for the talk presented at the conference is also available.)

A Comparative Study of the Realization of Rate-Based Computing Services in General Purpose Operating Systems

IEEE Conference on Real-Time Computing Systems and Applications, December 2000.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.(A copy of the slides for the talk presented at the conference is also available.)

The Synthesis of Real-Time Systems from Processing Graphs

IEEE Symposium on High Assurance Systems Engineering, November 2000.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

A New Look at Pfair Priorities

in submission.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

A Theory of Rate-Based Execution

IEEE Real-Time Systems Symposium, December 1999.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

(A copy of the slides for the talk presented at the conference is also available.)

Parallel Switching in Connection-Oriented Networks

IEEE Real-Time Systems Symposium, December 1999.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Analyzing the Real-Time Properties of a U.S. Navy Signal Processing System

IEEE Symposium on High Assurance Systems Engineering, November 1999.

(A revised and expanded version of this paper also appears in: International Journal of Reliability, Quality and Safety Engineering.)Get: full citation and abstract or postscript/PDF copy of this paper.

Proportional Share Scheduling of Operating System Services for Real-Time Applications

IEEE Real-Time Systems Symposium, December 1998.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

(A copy of the slides for the talk presented at the conference is also available.)

Efficient Object Sharing in Quantum-Based Real-Time Systems

IEEE Real-Time Systems Symposium, December 1998.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

(An extended version of this paper is also available in PostScript and PDF  form.

Managing Memory Requirements in the Synthesis of Real-Time Systems from Processing Graphs

IEEE Real-Time Technology and Applications Symposium, June 1998.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper. 

(A copy of the slides for the talk presented at the conference is also available.)

Fair On-Line Scheduling of a Dynamic Set of Tasks on a Single Resource

Information Processing Letters, October 1997.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Feasbility Concerns in PGM Graphs With Bounded Buffers

IEEE Conference on Engineering of Complex Computer Systems, September 1997.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Analyzing the Real-Time Properties of a Dataflow Execution Paradigm using a Synthetic Aperture Radar Application

IEEE Real-Time Technology and Applications Symposium, June 1997.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Real-Time Computing with Lock-Free Shared Objects

ACM Transactions on Computer Systems, May 1997Get: full citation and abstract – or – PostScript – or – PDF copy of this paper. 

(An earlier version of this paper appeared in: IEEE Real-Time Systems Symposium, December 1995 ) Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Implementing Wait-Free Objects on Priority-Based Systems

16th Annual ACM Symposium on Principles of Distributed Computing, January 1997.Get: full citation and abstract – or – PostScript copy of this paper.

On the Duality between Resource Reservation and Proportional Share Resource Allocation

SPIE Multimedia Computing and Networking 1997, February 1997.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Distributed Real-Time Dataflow: An Execution Paradigm for Image Processing and Anti-Submarine Warfare Applications

IEEE Real-Time Systems Symposium, December 1996.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

A Proportional Share Resource Allocation Algorithm For Real-Time, Time-Shared Systems

IEEE Real-Time Systems Symposium, December 1996.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

A Framework for Implementing Objects and Scheduling Tasks in Lock-Free Real-Time Systems

IEEE Real-Time Systems Symposium, December 1996.Get: full citation and abstract – or – PostScript copy of this paper.

Lock-Free Transactions for Real-Time Systems

First Workshop on Real-Time Databases: Issues and Applications, March 1996.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Real-Time Object Sharing with Minimal System Support

ACM PODC, May 1996.Get: full citation and abstract – or – PostScript copy of this paper.

A Theory of Rate-Based Scheduling

In submission, April 1995.Get: full citation and abstract – or – PostScript copy of this paper.

Support For Real-Time Computing Within General Purpose Operating Systems: Supporting co-resident operating systems

IEEE Real-Time Technology and Applications Symposium, May 1995.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

A Rate-Based Execution Abstraction For Multimedia Computing

Intl. Workshop on Network and Operating System Support for Digital Audio an dVideo, April 1995.Get: full citation and abstract – or – PostScript copy of this paper.

On Latency Management in Time-Shared Operating Systems

IEEE Workshop on Real-Time Operating Systems and Software, May 1994Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Predicting Worst Case Execution Times on a Pipelined RISC Processor

Technical Report, University of North Carolina, April 1994Get: full citation and abstract – or – PostScript copy of this paper.

Accounting for Interrupt Handling Costs in Dynamic Priority Task Systems

IEEE Real-Time Systems Symposium, December 1993Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

The Real-Time Producer/Consumer Paradigm: A paradigm for the construction of efficient, predictable real-time systems

ACM/SIGAPP Symposium on Applied Computing, February 1993.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Scheduling Sporadic Tasks with Shared Resources in Hard-Real-Time Systems

IEEE Real-Time Systems Symposium, December 1992.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

On Kernel Support for Real-Time Multimedia Applications

IEEE Workshop on Workstation Operating Systems, April 1992.Get: full citation and abstract – or – Postscript – or – PDF copy of this paper.

On Non-Preemptive Scheduling of Periodic and Sporadic Tasks

IEEE Real-Time Systems Symposium, December 1991.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

YARTOS: Kernel support for efficient, predictable real-time systems

IEEE Workshop on Real-Time Operating Systems and Software, May 1991.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

An Implementation and Application of the Real-Time Producer/Consumer Paradigm

Technical Report, University of North Carolina, October 1990.Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Analysis of a Synchronization and Scheduling Discipline for Real-Time Tasks with Preemption Constraints

IEEE Real-Time Systems Symposium, December 1989Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.

Corset & Lace: Adapting Ada Runtime Support to Real-Time Systems

IEEE Real-Time Systems Symposium, December 1987Get: full citation and abstract – or – PostScript – or – PDF copy of this paper.