3. Overview of PolyORB personalities

A personality is an instantiation of specific PolyORB components. It provides the mechanisms specified by a distribution model, e.g. an API, a code generator or a protocol stack.

This section provides a brief overview of existing personalities.

Note: some of these personalities are available only through PolyORB’s repository.

3.1. Application personalities

Application personalities constitute the adaptation layer between application components and middleware. They provide APIs and/or a code generator to register application entities with PolyORB’s core, and interoperate with the core to allow the exchange of requests with remote entities.

3.1.1. CORBA

CORBA is the OMG specification of a Distributed Object Computing (DOC) distribution model (:cite:`corba`). It is now a well-known and well-established specification, used in a wide range of industrial applications.

PolyORB provides a CORBA-compatible implementation based on a mapping of the IDL language version 1.2 described in :cite:`corba-ada-mapping1.2:2001` and CORBA core specifications. PolyORB also provides an implementation of various additional specifications described by the OMG, including COS Services: COS Naming, Notification, Event, Time, and additional specifications: RT-CORBA, PortableInterceptors, DynamicAny.

3.1.2. Distributed Systems Annex of Ada (DSA)

The Distributed Systems Annex of Ada (DSA) :cite:`ada-rm` is a normative part of the language specification. It was first introduced in the ‘Ada 95’ revision of the language (:cite:`ada-rm95`). It describes remote invocation schemes applied to most language constructs.

3.1.3. Message Oriented Middleware for Ada (MOMA)

MOMA (Message Oriented Middleware for Ada) provides message passing mechanisms. It is an Ada adaptation of Sun’s Java Message Service (JMS) :cite:`jms`, a standardized API for common message passing models.

3.2. Protocol personalities

Protocol personalities handle the mapping of requests (representing interactions between application entities) onto messages exchanged through a communication network, according to a specific protocol.

3.2.1. GIOP

GIOP is the transport layer of the CORBA specifications. GIOP is a generic protocol. This personality implements GIOP versions from 1.0 to 1.2 along with the CDR representation scheme to map data types between the neutral core layer and CDR streams. It also provides the following dedicated instances:

  • IIOP supports synchronous request semantics over TCP/IP, .. index:: IIOP
  • IIOP/SSIOP supports synchronous request semantics using SSL sockets, .. index:: SSLIOP
  • MIOP instantiation of GIOP enables group communication over IP multicast, .. index:: MIOP
  • DIOP relies on UDP/IP communications to transmit one-way requests only. .. index:: DIOP

3.2.2. SOAP

The SOAP protocol :cite:`soap12primer` enables the exchange of structured and typed information between peers. It is a self-describing XML document :cite:`soap12primer` that defines both its data and semantics. Basically, SOAP with HTTP bindings is used as a communication protocol for Web Services.