1:30-3:00pm

Invited Speaker:  "What to Expect From Your Garbage Collector"

Hans-J. Boehm, Silicon Graphics

Most C and C++ programs explicitly deallocate or recycle memory that is no longer needed by the program, so that memory can be reused. For programs that manipulate complex data structures this is often a major source of errors.

Languages like Java, as well as some C and C++ libraries, introduce an automatic garbage collector to detect and reuse unneeded memory without programmer intervention. In most cases this significantly simplifies the programmer's job. It also substantially changes the costs associated with memory allocation. The time required to allocate and deallocate an object is no longer even approximately fixed. Small short-lived objects may become much less expensive to allocate, while large long-lived objects often introduce significant garbage collection overhead. It becomes easier to trade execution time for space. Garbage-collection related pauses may become an issue.

We present some common garbage collection algorithms and look at their common performance characteristics, their performance differences, as well as other visible differences, such as whether they can be used directly with standard C or C++ code.

Hans-J. Boehm holds a Ph.D. in Computer Science from Cornell University. He was on the faculty at the University of Washington and Rice University. Subsequently he joined Xerox PARC and is currently at Silicon Graphics.

He has published papers on a variety of topics related to programming language implementation, has chaired the ACM POPL conference, and is the author of a widely used garbage collector for C and C++.

Debate:   "Is the Licensing of Software Engineers Good for the OT Community?"

There is a major debate brewing in the software engineering community regarding licensing. Currently, no state in the U.S. which licenses professional engineers (PEs) allows it in the discipline of software engineering; however, at the time of this writing, Texas is on the brink of doing so, starting in June 1998. (See the December 1997, January 1998, and March 1998 issues of the FASE electronic newsletter at http://www.cs.ttu.edu/fase for details.) Other states are expected to follow soon. Since the news concerning the Texas State Board was released on the Internet, there has been a great deal of response and discussion - sometimes very intense - among software professionals. Licensing certainly affects all those in the Object Technology industry. The panelists will supply a variety of perspectives (academia, training, industry) on how licensing might affect the OT community.

Moderator: Donald J. Bagert, Texas Tech University

Panelists:
Michael J. Lutz, Rochester Institute of Technology
Peter W. Wenzel, Nortel
Michael Whitelaw, Charles Sturt University
Rebecca Wirfs-Brock, Wirfs-Brock Associates

3:30-5:00pm

Panel:   "The New Crop of Java Virtual Machines"

I want to use the Java Programming Language. But, will the new Java Virtual Machines be any good?

And how will they do it, anyway? This panel will bring together the creators of next-generation JVMs from

Intel, Oracle, OTI/IBM, and Sun. There, each will explain how their system is unique, why each path was chosen and how successful each system has been in achieving its goals. Then, we will give the audience a chance to goad the panelists into a bit of friendly debate. When the smoke clears, we will have reconnoitered some of the unknown territory of the new Java Virtual Machines.

Moderator: David Ungar, Sun Microsystems

Panelists:
Lars Bak, Sun Microsystems
Jesse Fang, Intel Corporation
John Duimovich, Object Technology International, Inc.
Scott Meyer, Oracle Corporation

Technical Papers Session 2:

"Data Groups: Specifying the Modification of Extended State"
K. Rustan M. Leino, DIGITAL Systems Research Center

"Logical-Observable Entities"
Jonathan G. Rossie Jr., North Carolina State University

"A Lambda Calculus of Objects with Self-Inflicted Extension"
Pietro Di Gianantonio, Furio Honsell, and Luigi Liquori, Università di Udine