Towards an Aspect-oriented approach to Agent-oriented programming - PowerPoint PPT Presentation

Towards an Aspect-oriented approach to Agent-oriented programming Matthieu Amiguet – Univ. of Applied Sciences Locle, Switzerland Jose Baez – LIRMM, University of Montpellier, France Adina Nagy – Institut für Informatik, HU Berlin, Germany MOCA 2004 – Aarhus – 11-13 1 October 2004

Outline  Introduction: origins, project, methodology, example  Aspect-oriented and Agent-Oriented Programming  Orthogonal concerns  Organizational structure: Concepts, example revisited  Agent architecture  Dynamic weaving and conflict management  Conclusion  Future work MOCA 2004 – Aarhus 13.10.2004 2 Adina Nagy

Introduction  Origins of organizational approach to agent-oriented programming  social-inspired approach  „simulation“ for social/behaviour science  structuration around patterns of behaviour or of preferences Ex 2. consumer behaviour with respect to brands  Ex 1. encapsulation of user-related features in telecom   organization schemata and protocols as meta-modelling tools for multi-agent system design [Sauvage, 2003  MOCA project „ m odèle o rganisationnel c entré a gent“  definitions: organizational notions (role, organization) as first-order concepts  operationalisation: role-taking defined, endorsement of several roles by an agent treated, agent architecture established,  implementation: platform over MadKit (O. Gutknecht, J. Ferber www.madkit.org) MOCA 2004 – Aarhus 13.10.2004 3 Adina Nagy

MOCA organizational approach  Social roles: patterns of interaction and behaviour [AMBN´02]  behaviourist model  versus normative (mentalist)  Organisation: institutionalised pattern of interaction, at collective level (social entity) Main properties of MOCA:  dynamic social structure issued from agents´ role endorsement [AMBN´02] [Amiguet03]  componential agent architecture [Amiguet03]  communication through influence exchanges authorized only within a group  communication through competence calls within an agent MOCA 2004 – Aarhus 13.10.2004 4 Adina Nagy

Organizational methodology Organization: recurrent pattern of interaction, from a given point of view and often with a rationale  Multiple view-point modelling  a view-point: a partial view on the whole system  modularity, reusability, simplifies the design  Multi-organisation modelling  each view-point represented by at least an organisation  Ex1. Commercial system: good exchanges, financial exchanges, customers’ behaviour  Ex2. Multi-agent system: environment negotiation, communication or cheating strategies, as plug-in organisations  meta-organisational services reified as particular organisations  Ex3. Management organization in MOCA: Group formation and destruction, role endorsement and leave MOCA 2004 – Aarhus 13.10.2004 5 Adina Nagy

Example – a toy commercial system Provider Intermediate Client [Amiguet2003] 3 agents Provider: creates a new group instantiating a Supply org. and takes the Seller role Intermediate: asks to endorse the role Buyer in any group instantianting Supply creates a new group instantiating Selling, where it takes the roles Seller Client: asks to endorse the role Buyer in every group instantianting Selling. MOCA 2004 – Aarhus 13.10.2004 6 Adina Nagy

Outline  Introduction: origins, project, methodology  Aspect-oriented and Agent-Oriented Programming  Orthogonal concerns in MOCA  Organizational structure  Agent architecture  Dynamic weaving and conflict management  Conclusion  Future work MOCA 2004 – Aarhus 13.10.2004 7 Adina Nagy

Aspect and Agent-oriented programming  Agent-Oriented Programming - main decomposition: agents  Aspect-Oriented perspective (www.aosd.net)  problem: communication  elements of communication spread amongts agents  scattered/cross-cutting concern  Object-Oriented approach: avoid rewritting agents´ code  superclass to implement a part of the communication protocols  role (organisational approaches)  Problems: multiple inheritance + still scatterred protocol  MOCA: interaction protocols unified into organizations  Agents and Organizations: orthogonal concerns  Weaving of concerns through components (roles or not) MOCA 2004 – Aarhus 13.10.2004 8 Adina Nagy

Outline…  Introduction: origins, project, methodology  Aspect-oriented and Agent-Oriented Programming  Orthogonal concerns in MOCA  Organizational structure – main concepts  Agent architecture  Dynamic weaving and conflict management  Conclusion  Future work MOCA 2004 – Aarhus 13.10.2004 9 Adina Nagy

Organisational concepts  Roles (agent-perspective) and role descriptions (organizational perspective)  Statechart/ObjectZ representation  Example of organizations MOCA 2004 – Aarhus 13.10.2004 10 Adina Nagy

Roles and role descriptions  Role description  recurrent behaviour pattern at individual level  represented as statechart associated to behavioural scripts  Role  endorsed individual pattern of interaction (and behaviour), interacting with other individual patterns, within a group of agents  instantiation of a role description MOCA 2004 – Aarhus 13.10.2004 11 Adina Nagy

Statecharts Extensions of finite-state automata including an and-or decomposition of states [Harel 1987], [for organization schemata modelling: Hilaire 2000] Configurations: Root, A, A1, A2, B, C, D, E Root, F Execution: current configuration determines fireable transitions which determines next configuration root, embedded states  and-states (A1, A2)  or-states (A, F)  default states  transitions labelled  influence[condition]/action SC- automata whose states are the configurations+ events+ conditions; before firing a transition a simplified graph is computed MOCA 2004 – Aarhus 13.10.2004 12 Adina Nagy

RD example – interaction pattern Contract-net Organization MOCA 2004 – Aarhus 13.10.2004 13 Adina Nagy

Initiator behaviour Initiator RD & role initiator execution start/ send ( cfp ) not- CfpInfluence propose / add_prop understood InfluenceType  refuse [ timeout ] / choose name = cfp • A start event attributes = {...} provokes the send of a call_for / send_answer • Call of the _proposals propose / send (reject) competence (multicast) delegate_task influence inform_done failure Inform_refuse • Component Attributes waits timeout influence and proposals: P Proposal records Required competencies chosen:Proposal proposals req_competence = { send, evaluate, timeout } Provided competencies prov_competence = {delegate_task} delegate_task Delegate_task generate_event(start) - which task ? add-prop ∆ Proposal - return a result to the calling component prop ? Competencies scripts for proposals’ = proposal  prop? choose ∆ chosen Internal competencies  p  proposals  evaluate ( chosen’ )  evaluate (p) ObjectZ, Java interfaces send_answers  p  proposals - { chosen }  send( p,reject) MOCA 2004 – Aarhus 13.10.2004 14 Adina Nagy send (chosen,accept)

Role descriptions (reminder) RD - recurrent behaviour pattern at individual level  Combined formalism   statechart representation (interactions)  competencies behaviour scripts in ObjectZ (XML files, Java interfaces) Transitions - labelled - enacting_event[condition]/action   enacting_event is an influence type  condition and action are competence calls Competencies   internal to roles  external: required or provided MOCA 2004 – Aarhus 13.10.2004 15 Adina Nagy

Example - Org. Supply Require Organisation: Purse- related competenc e Behaviour: Buyer asks Seller the price of a good and buys until has no more money left MOCA 2004 – Aarhus 13.10.2004 16 Adina Nagy

Example - Org. Selling m Buyer orders at random intervals a given quantity of goods to Seller If Seller has enough stock, it delivers the required amount, else it refuses delivery Require Purse-related competencies MOCA 2004 – Aarhus 13.10.2004 17 Adina Nagy

Example Provider Intermediate P u r s e MOCA 2004 – Aarhus 13.10.2004 18 Adina Nagy

Outline  Introduction: origins, project, methodology  Aspect-oriented and Agent-Oriented Programming  Orthogonal concerns in MOCA  Organizational structure: main concepts  Representation of interaction protocols (RD+relations)  Independent of agents‘ architecture  first orthogonal concern  Agent architecture  Dynamic weaving and conflict management  Conclusion  Future work MOCA 2004 – Aarhus 13.10.2004 19 Adina Nagy

Agent architecture - PN ? componential Agent type problem dependent encapsulates goals, etc driver for role endorsement/leave Agent Type components Manage which components Componential add/removal components CMM ? added/removed CMM not specified in MOCA Influences Components management of are sent by a communication specific Components between component components Components Management Module provides agent with primitives to manage components Influences received and dispatched to roles MOCA 2004 – Aarhus 13.10.2004 20 Adina Nagy