Software like hardware does
not wear out but it has to be modified according to some changes in the needs of the users and advancement in
technology. As a consequence of the
modification of the software systems or applications, its degree of complexity
increases proportionally which then leads to an increased rate of errors.
It
was suggested by some developers that in order to reduce this complexity and
cut down on the maintenance costs and efforts, the development can be based up
on the small and simple components.
Initially, this proved to be very helpful as
a means to tackle the software crisis but in the later years it soon developed
in to what is called now “component based software development”.
Following this
software development methodology, large software systems and applications are
built from the small and simple components that belong to the pre- existing
software systems and applications. Over the years, this process has proved to be
an effective approach for the enhancement of the maintainability and
flexibility of the software systems that are built using it. The
software system is assembled quickly and that too within quite a low budget.
The component based
development is known to constitute of 4 activities namely:
- Component qualification
- Component adaptation
- Assembling components
- System evolution
We are going to discuss
about “CORBA architecture” in this article which forms an important part of the
third activity i.e., assembling the components.
What does CORBA stand for?
- The assembling of the
components is facilitated through some well defined infrastructure which
provides binding for the separate components.
- CORBA is an important component
technology that stands for “common object request broker architecture” and has
been developed by OMG (object management development).
- In CORBA “ORB” which
stands for “object request broker” is object oriented and a more advance
version of “RPC” or “remote procedural calls” that was an old technology.
- With
the remote procedural calls or object request brokers, the client applications
are able to call the methods (passing responses and generating responses) from
accessing the objects across an amalgam of several different networks.
What CORBA is meant for?
- To put
it simply, we can say that the CORBA is an effective standard mechanism using
which different operations on an object can be invoked.
- CORBA is categorized
under the category of distributed middle ware technology.
- It is meant to
connect remote objects and inter- operate between them on operating systems,
different networks, various machines and programming languages etc.
- It is done with the
means of a standard IIOP protocol.
- CORBA has made it easy to write software
components in multiple computer languages that need to run together and support
multiple platforms.
- With CORBA all the components work together like a single
set of integrated applications.
- CORBA
normalizes the method call semantics between the various objects of the
application that reside either in remote address space or same address space.
More about CORBA...
- The
first version of the CORBA 1.0 was released in the year of 1991.
- The IDL or
interface definition language is used by CORBA for the specification of the
interfaces which are presented to the outer world by the objects.
- Then a
mapping from IDL is specified by CORBA in a specific implementation language
like java or C++.
- For certain languages like C, C++, Ruby, Smalltalk, COBOL,
Python and so on standard mappings exist and for some other languages like
visual basic, TCL, Erlang and Perl non standard mappings exist.
- In practice, the ORB is
initialized by the software application and an object adapter is accessed.
- This
object adapter maintains things like:
- Reference counting
- Object policies
- Instantiation policies
- Object lifetime policies
IDL java mapping makes use
of the CORBA architecture.
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