The ``Ubiquitous Agent'' Design Pattern

By Jean-Marc J\'ez\'equel and Jean-Lin Pacherie

Contact name: Jean-Marc Jezequel
e-mail : jezequel@irisa.fr
Yonezawa lab
Dept. of Information Science
Faculty of Science          
The University of Tokyo
Hongo Bunkyo-Ku, Tokyo 113, 
JAPAN

Tel : +81 (3) 3812-2111 ext. 4116
Fax : +81 (3) 5689-4365

  Encapsulating parallelism and synchronization code within
object-oriented software components is a promising avenue towards
mastering the complexity of the distributed memory supercomputer
programming.  However, in trying to give application programmers
benefit of supercomputer power, the library designer generally resorts
to low level parallel constructs, a time consuming and error prone
process.  To solve this problem we introduce a new design pattern
called Ubiquitous Agent.  An Ubiquitous Agent is an object that exists
simultaneously on all processors involved in a distributed
computation: it acts as a single ubiquitous entity capable of
processing shared or distributed data in parallel.  In this paper we
describe the motivation, applicability and structure of this design
pattern.