RPC Services uses the client-server model to implement remote member function calls. Remote member function calls use a request-reply interface (where a client makes a request to a server and receives a reply back) to execute member function calls in objects that resides in different tasks or threads. Using RPC Services you make these remote calls transparently, so that they appear as local calls even though they access remote objects.
In nonobject-oriented environments, these calls are traditionally referred to as remote procedure calls (RPC). In RPC Services, you are actually calling member functions of remote objects rather than procedures, though the end result is the same.
You can use RPC calls whenever you need to communicate between tasks or threads using a client-server model and a request-reply interface. The most common reason for creating a remote procedure call is when you want to access data that is not local to the current task. A file server is a good example, where a local host makes calls that access files on a remote host. Member functions of an object located on the local machine would not be able to access the remote files.
The CommonPoint application system provides other communication interfaces in addition to RPC Services:
- Message Streams, the interface on which RPC Services is built, defines the request-reply interface without added support for remote member function calls. If you need to communicate between tasks or threads to perform bulk data movement, or if you need to interoperate with a machine that is not running the CommonPoint application system, use Message Streams instead of RPC Services. See Chapter 4, "Communications access," in OS Services for more details.
- The Caucus framework provides an interface that uses a one-to-many relationship, instead of point-to-point communication within a request-reply interface. A caucus--a group of clients interacting together--communicates as a group, using multicast and broadcast protocol. If you need this type of interface, read Chapter 6, "Caucus framework," in this book.
- Understanding RPC Services
-
- RPC Services classes
-
- How classes interact in the RPC model
-
- Passing parameters to remote member functions
-
- Implementing a caller-dispatcher pair
-
- Starting the dispatcher thread
-
- Adding a request to an existing caller
-
- Designing servers
-
- Introduction to child objects
-
- Implementing a collection of child objects
-
[Contents]
[Previous]
[Next]
Click the icon to mail questions or corrections about this material to Taligent personnel.
Copyright©1995 Taligent,Inc. All rights reserved.
Generated with WebMaker