Corba Programming - Glossary
The CORBA specification dictates there shall be an ORB through which an application would interact with other objects.
In practice, the application simply initializes the ORB, and accesses an internal Object Adapter, which maintains things like reference counting, object (and reference) instantiation policies, and object lifetime policies.
The Object Adapter is used to register instances of the generated code classes.
Generated code classes are the result of compiling the user IDL code, which translates the high-level interface definition into an OS- and language-specific class base for use by the user application. This step is necessary in order to enforce CORBA semantics and provide a clean user process for interfacing with the CORBA infrastructure.
Some IDL language mappings are more difficult to use than others. For example, due to the nature of Java, the IDL-Java mapping is rather straightforward and makes usage of CORBA very simple in a Java application. This is also true of the IDL to Python mapping.
The C++ mapping is notoriously difficult; the mapping requires the programmer to learn complex and confusing datatypes that predate the C++ STL. Since the C language is not object-oriented, the IDL to C mapping requires a C programmer to manually emulate object oriented features.
- Accessor and mutator
- The object-oriented properties of encapsulation and information hiding imply that variables internal to an object should not be accessed directly. It is common practice to create a pair of methods, one to return the value of the variable (the accessor or getter method) and one to set the value of the variable (the mutator or setter).
- The process of connecting a reference (usually to a server) and a name to a naming context. The context may be one that is already stored in the Naming Service, or it may be added after names have been bound into it.
- By value
- The value of the parameter is copied, and so any changes to the value are made on the copy, not the original reference.
- The opposite of incarnate. When a CORBA object is deactivated, the servant is etherealized.
- General Inter-ORB Protocol. A CORBA specification that defines the rules for the way CORBA works over any network. It's not an implementation, just a set of rules.
- To access all the items in the course glossary, click the Show All Terms button, below.
- The Internet protocol used by Web servers and Web browsers. HTTP is one of many protocols that work over the Internet.
- Internet Inter-ORB Protocol. An implementation of GIOP that runs over the Internet or any TCP/IP network. This is the only implementation of GIOP many ORBs support. All ORBs support IIOP.
- A servant incarnates an active CORBA object. When the CORBA object is activated, the servant is incarnated. (This may or may not correspond to a constructor call in the programming language of the servant.)
- Java naming standards for packages
- This convention for package names holds that all packages produced should start with the domain name reversed. For example, if the producing company is xenotrope.com, all packages would start with com.xenotrope. If the producing company is the computer science department at Yale University, all packages would start with edu.yale.cs.
- Conversion of language-specific data types to values, which can be put onto a byte stream.
- Naming graph
- A diagram that arranges object references and naming contexts into a hierarchy to make it clear what path will lead to a specific object reference.
- Pass by value
- The value of the parameter is copied, and so any changes to the value are made on the copy, not the original
- The actual running code that does the job of a CORBA server, as distinguished from the CORBA framework that surrounds
it. A servant is written in a specific programming language and often corresponds to a Java or C++ object.
- A server-side Java technology that makes it simple to run Java code in response to a request from a Web browser.
- In pass by value, the value of the parameter can not change, but if it is an object reference, methods on that reference can still be called, even accessors and mutators. So the internal state of that object can be changed, even if the parameter can not be made to reference a different object.
- Secure Sockets Layer. A well-known protocol for exchanging encrypted information over HTTP. Implemented by many Web servers and Web browsers.
- When an IOR is converted into a string, the CORBA word for it is "stringifying." A stringified IOR can be saved in a file, sent in a mail message, and easily passed around from machine to machine.
- The underlying protocol that makes the Internet work. Many internal networks use this protocol also. They are generally called intranets.
- The communication socket between the servers where all communication is reduced to a byte stream.