[Acpc-l] Talk, heute 15:00 (Alex Villazon)

[Thomas Gschwind]

Hallo *!

Heute gibt es um 15:00 in der Bibliothek E1841 einen Vortrag von Alex
Villazón über "A Reflective Execution Environment for Mobile Agents".

Hier der Abstract:

	"A Reflective Execution Environment for Mobile Agents"

			    Alex Villazón
	      Teleinformatics and Operating System Group
	      Centre Universitaire d'Informatique (CUI)
		  University of Geneva. Switzerland
				   
			      Abstract:

Reflective systems provide more openness than traditional systems,
since they allow inspection and modification of internal
functionalities.  On the other hand, mobility of code and agents gives
flexibility for application deployment, dynamic application
extensibility and configurability. However, the corresponding
execution environment (EE) provides in general insufficient means for
manipulating internal functionalities, and hence limits the resulting
software adaptability. In our approach, the application of reflection
to mobile code and mobile agents aims at providing enhanced
adaptability and flexibility to the execution environment by allowing
agents to interact with reflective components inside the execution
environment and also allowing agents to act upon their-selves. For
this, some aspect must be reified (made visible) in both the execution
environment and agents, such as the structure, bindings and resources.

Resource awareness is an important step towards adaptability,
something which is particularly desirable in the context of mobile
code and mobile agent EEs.  Since resources (CPU, memory, network
bandwidth) are not available and manipulable as first-class entities
in standard programming models, such as the Java language, the
introduction of some means allowing resource reification seems
indispensable.  This is however difficult to achieve, especially if
portability is a requirement.  The idea is to reify resource related
information directly from the agent code before its execution. Our
reflective architecture for mobile agent environments allows then
reification of local resource consumption in a transparent and
portable way.  We focus on reification of resources that are consumed
by mobile agents and more precisely in CPU. Our approach has been
applied to Java-based EEs, where CPU accounting is based on a relative
measurement based on the number of Java byte-code instructions that
are executed. The implementation is based on byte-code rewriting
techniques and measurements demonstrate that the approach gives
acceptable overhead and can be applied to other Java-based
applications.

LG,
Thomas
-- 
Thomas Gschwind                      Email: tom@infosys.tuwien.ac.at
  Fingerprint:  8C1B C47F A952 BABD 72EC  CCD4 A471 48BE 5887 5B8F
Technische Universität Wien
Argentinierstraße 8/E1841            Tel: +43 (1) 58801 ext. 18412
A-1040 Wien, Austria, Europe         Fax: +43 (1) 58801 ext. 18491