MONTHLY PROGRESS REPORT

CONTRACTOR:           University of California at Berkeley
TITLE:                Open Control Platform
REPORT PERIOD:        8/15/00 - 9/15/00
SPONSOR:              Boeing Subcontract, Air Force Research Laboratory (AFRL)
REPORT PREPARED BY:   Sonia R. Sachs 


1.  Research Status

Sonia Sachs and two undergraduate students, Alvin AuYong and Mark Feng,
studied two vendor-implementations of the CORBA architecture---TAO and
Orbacus, particularly their Event Services implementation. 
We installed both ORBS into NT and Unix machines.
Our goal was to study the integration of OCP with the Ptolemy development
environment.  As Ptolemy is Java-based software, writing TAO Event Channel 
consumer and/or supplier code would require the use of native methods to 
allow Ptolemy to communicate with the C++ Event Channel consumer/suppliers.
Although a viable alternative, it was ruled out due to the fact that
it compromises portability and impacts security, code safety, and
performance. Orbacus is a Java-based ORB, thus it is possible to write
Event Channel consumer/suppliers in Java. It is not clear yet if Orbacus
real-time processing is compatible with TAO. We decided to concentrate
on learning how to work with the various TAO/Orbacus models (push-consumer/
push-supplier, pull-consumer/pull-supplier, and mixed). Real-time details
will be studied next. Also, as Zen is the Java version of TAO, we expect
to transition to Zen as soon as a stable version is available. We do not
expect that Zen and TAO will have incompatible handling of real-time.  

The students had no prior knowledge or experience in CORBA, distributed
applications, and very little experience with the Unix platform, so a
lot of time was invested in learning and guidance. The time invested in
training was necessary in view of the absence of CORBA trained students
and programmers. 
After a few difficulties with the OCP installation and documentation,
Sonia studied the OCP Event Service Utilities API. The goal is to create
an equivalent Java-based Event Service Utilities API. 



 Meetings
 ========

* September 7-8, 2000: GSRC Meeting, Palo Alto, CA.
  Informal presentation "Modeling/Design of Concurrent, Heterogeneous Systems".  
  We discussed the Ptolemy II approach for exploring component frameworks, with 
  particular emphasis on component communication issues.