OSF DCE Application Development Guide--Core Components

Developing a Simple RPC Application
A comment can be inserted at any place in an interface definition where whitespace is
permitted. IDL comments, like C comments, begin with /* (a slash and an asterisk) and
end with */ (an asterisk and a slash).
11.2.1 RPC Interfaces That Represent Services
The simplest RPC application uses only one RPC interface. However, an application
can use multiple RPC interfaces, and, frequently, an integral set of RPC interfaces work
together as an RPC service. An RPC server is a logical grouping of one or more RPC
interfaces. For example, you can write a calendar server that contains only a personal
calendar interface or a calendar server that contains additional RPC interfaces such as a
scheduling interface for meetings.
Different servers can share one or more RPC interfaces. For example, an administrative-
support application can include an RPC interface from a calendar service.
An RPC interface exists independently of specific applications. Each RPC interface can
be implemented by any set of procedures that conforms to the interface definition. The
operations of an interface are exactly the same for all implementations of the same
version of the interface. This makes it possible for clients from different implementations
to call the same interface, and servers from different implementations to offer the same
interface.
Figure 11-6 shows the role of RPC interfaces in remote procedure calls. This client
contains calling code that makes two remote procedure calls. The first is a remote
procedure call to Procedure A. The second is a remote procedure call to Procedure B.
Figure 11-6. Role of RPC Interfaces
Statistics Server
Procedure B
Procedure A
Database Server
A( )
A( )
B( )
Client
RPC Interfaces
B( )
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