Communicator e3000 MPE/iX Release 7.0 Express 1 (Software Release C.70.01) (30216-90328)

146 Chapter6
Technical Articles
Enhancements to DCE on MPE/iX
1. Changes Pertaining to RPC
• Private Client Sockets
• Exception Handling
2. Changes Pertaining to IDL Compiler
• Out-of-line marshalling (library-based marshalling)
• Enhanced IDL data types
• Support for IDL encoding services
• Support of user defined exceptions
• Support for customized binding handles
3. Changes to Control Programs and Daemons
4. Transition of ACL Manager
5. Removing of DCE Credentials
6. Serviceability Improvements
7. Security Delegation
Changes Pertaining to RPC
• Private Client Socket
Previously a common pool of sockets was shared by concurrent RPC requests. Making this
concurrency work required that there be a “helper” thread created to read from all of the
open sockets, passing received data onto the call thread for which it is intended. Now with
“private client sockets” there are a couple of sockets (2/3) which will be used only for
individual requests (private to the request thread). This reduces the overhead of “helper”
threads in case of small applications. However, when you run out of private sockets the
sharing of sockets comes into effect.
• Exception Handling
The new version DCE 1.2.1 supports the exception-handling feature of RPC. Now, the
application developer can use the exception handling routines (TRY, CATCH, CATCH-ALL
etc.).
Changes Pertaining to IDL Compiler
• Out-of-line marshalling (library based marshalling)
Out-of-line marshalling causes constructed data types such as unions, pipes or large
structures to be marshalled or unmarshalled by auxiliary routines, thus reducing the
stub size. The out-of-line attribute directs the IDL compiler to place the marshalling
and unmarshalling code in IDL auxiliary stub files, rather than in the direct flow of the
stub code.
• Enhanced IDL data types.
IDL support for arrays in the previous version was limited to: