An important part of the CORBA standard is the Interface Definition Language (IDL) and its various mappings. IDL is used by the standard to describe all standardized objects. The ORB is a CORBA object which has IDL interfaces: programs access the ORB through IDL interface methods. This allows programmers to be completely independent of different ORB implementations both at the source and executable level.
The CORBA module is the most important module defined by the CORBA specification. Here is a simple summary of what can found there:
module CORBA { // IDL definitions of the CORBA bus interfaces // IDL definitions of the POA and the BOA // IDL definitions of the Interface repository // IDL definitions of Dynamic mechanisms module IOR { // The IOR definitions. }; module IIOP { // The IIOP protocol definitions. }; module DCE_CIOP { // The DCE_CIOP protocol definitions. // This protocol was defined for systems integration }; module GIOP { // The GIOP protocol definitions }; }; |
We will study the "CORBA bus" interfaces in this chapter. More precisely, we will look at CORBA::Object and CORBA::ORB. This will allow us to write our first simple client.
The different protocols will not be studied: the standard was written to be read and unless you are willing to write an ORB implementation, you don't need to know how these things work.