Program for Thursday, 12 April 2001

Our Next Meeting is scheduled for
Thursday, 12 April 2001 at 7:30 P.M.
Currie Colket
from MITRE
will be speaking on
Everything You Wanted to Know About Exceptions, But Were Afraid to Raise
at the Lockheed Martin Corporation in Rockville, Maryland
(Refreshments and Social at 7:00 P.M.)


To Members and Friends of DC SIGAda

Next Meeting:

Our Next Meeting is scheduled for 12 April 2001 as a Joint Meeting of the Baltimore and DC SIGAda Chapters. Currie Colket, of The MITRE Corporation will be speaking on Everything You Wanted to Know About Exceptions, But Were Afraid to Raise. The presentation will start at 7:30 P.M. (Refreshments and Social at 7:00 P.M.) at the Lockheed Martin Corporation in Rockville, Maryland.

Snacks and soft drinks will be served at 7:00 PM, the general meeting will start at 7:30 PM, followed by the program.

Abstract: Everything You Wanted to Know About Exceptions, But Were Afraid to Raise

Exception processing was considered by Jean Ichbiah to be one of the 3 most important features of the Ada language. It has the power to detect serious problems in the execution of a program and return one back to a known safe state with high integrity. As such, it can be a very powerful tool for developing high quality software. Unfortunately many developers do not use the full power of exceptions. Frequently the use of exceptions is to simply log the problem and continue execution, allowing things to gracefully degrade. In the case of Ariane 5, exceptions were raised appropriately, but the result had not been well thought out, resulting in a disaster.

This presentation will start at the basics, discussing the Ada 83 concept of exceptions. To be effective, exceptions and their handling must be addressed at the design level and not at the code level where it is frequently performed today. This presentation will discuss several alternative approaches to addressing error handling in the design using exceptions.

Since Ada 83, several changes have been made to the exception area. Changes for Ada 95 made exceptions more effective. A Workshop at Ada-Europe this May will address proposed needs for exceptions that may likely result in changes for the next version of the Ada language, Ada 0X.

The use of exceptions can be assessed via automated tools. The presentation will conclude by addressing several analyses that can be performed on a program via automated tools so the program quality can be improved.

Presenter: Currie Colket

Mr. Currie Colket is the Vice Chair of ACM SIGAda for Meetings and Conferences, the Chair of the SIGAda Ada Semantic Working Group, and Chair of the ISO WG9 ASIS Rapporteur Group. He recently retired from the DoD where he served in the Air Force as an Airborne Surveillance Officer on AWACS and a computer scientist for the United States Navy. Mr. Colket is currently a software systems engineer for MITRE. His current tasks involve code analysis using ASIS-based tools. Prior to his affiliation with MITRE, he was a consultant for the Software Program Manager's Network (SPMN). He has a Bachelor of Science from Case Institute of Technology, a Master of Business Administration from the University of Southern Mississippi and a Master of Science in Computer Science from the Ohio State University. His email address is colket@mitre.com.


Lockheed Martin Corporation
9211 Corporate Boulevard
Rockville, Maryland 20874


From all points: Get to I-270 West from the I-495 Beltway,

  1. Take I-270 West to Shady Grove Exit;
  2. Turn left at light;
  3. Turn right on Corporate Dr (at light);
  4. Turn right at end of access road (can only turn left or right);
  5. Go to end of driveway.
  6. The building for the meeting is on the right, across the open courtyard area. It is building #9211, as marked. Parking lots are on the left and right.
  7. Enter main lobby. Stop at guard desk to check in.

Also, to obtain a map of the location, visit http://www.mapquest.com/, select Driving Directions for the destination address: "9211 Corporate Drive, Rockville, Md."

Next Meeting

Please put 8 May 20001 on your calendar when Frank Beard will be talking about Building Graphical User Interfaces using ObjectAda.

Notes From March Meeting

Mr. Greg Gicca provided an excellent presentation at the March Baltimore SIGAda Meeting on FAA DO-178B Details followed by a Short Overview of the Aonix Raven Tool Support. For those who missed the presentation, it is available on line at http://www.acm.org/sigada/locals/dc/ following the link for the March meeting.

DC SIGAda Home Page and Maillist

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We will have snacks and soft drinks at 7:00. The meeting begins at 7:30 pm.

Please forward this message to people who might be interested in attending. We welcome all new members as our attendance and interests grow.

Many thanks to all earlier participants, contributors, speakers, advisors, and friends, who are involved in helping to produce and attend the meetings.

Jeff Castellow, Chair, DC SIGAda

If you have comments or suggestions, email the DC SIGAda Webmaster

updated 3 April 2001