Build CORBA Applications with C++, MICO and Win32 Luiz Carlos d´Oleron

Acknowlegdes Mayank Mishra, Master in Computer Science, Sun MicroSystems Nelson Souto Rosa, Doctor in Computer Science, Cin/UFPe

Break Point This is a attachment to the regular course. In this material, only practical issues can be found. Please, read the references of CORBA and Distributed Systems in discipline home page !

Pre-requisits Before you continue, be sure that you have at least: Low level C/C++ domain Familiar with Middlewares, CORBA and Distributed Systems concepts Solid knowledges in Object Oriented Paradgma Familiar with Windows and Microsoft Visual Studio 2003 platform* * so little work is sufficient to migrate to others platforms

What´s MICO MICO is CORBA! Micro CORBA A Implementation of CORBA specification subset With him you can write CORBA applications in C++ or Java Visit

Install MICO on Windows Download MICO source from mico.org Unzip it Read README-WIN32 to compile the source Edit the environment variables to add win32-bin directory to PATH variable You can download a compiled distribution of MICO to Win32 in

Configure Visual Studio Project 1) File ->New->Project… 2) Expand “Visual C++ Projects” 3) Select Win32 Folder 4) Select Win32 Console Project 5) Enter a Name to Project 6) Click OK

Configure Visual Studio Project 7) Click in “Application Settings” 8) Be sure that the “Console application” is selected 9) Mark the “Empty project” checkbox 10) Click in Finish to create the project

Configure Visual Studio Project Was create a simple Empty project 11) Go to Project Menu 12) Select the “Properties” Item Where are the C/C++ Option? :O For Respond: 13) Click in Cancel Button

Configure Visual Studio Project 14) Add a new file from source 15) Select C++ File 16) Choose a name to a file, like “server.cpp” 17) Click in “Open”:D

Configure Visual Studio Project Well, the file server.cpp was created. Now, 18) Click in Project Menu 19) Select Properties Tharamm! The C/C++ folder is enable! 20) Expand him 21) In “Additional include Directories” enter the complete path from the Include folder of MICO distro.

Configure Visual Studio Project 22) Expand linker 23) In “ Additonal Library Directories, enter the complete path of the lib folder over win32-bin directory of MICO 24) Select Input 25) Enter the mico2312.lib and micocoss2312.lib references. 26) Click OK Finish the Visual Studio Project Configuration for MICO Applications

Create and Compile the IDL File interface Account{ void deposit(in long amount); void withdraw(in long amount); long balance(); }; account.idl 1)Create the account.idl text file in project folder 2)Open the cmd (start->run enter ‘cmd’) 3)Go to project folder 4)Enter “idl account.idl” The idl.exe from MICO will compile the account.idl and generate two files: account.h account.cc Add this files to project

Additional Tasks Hei, in account.cc file, change the include to “account.h” Do you remember the server.cpp file? Open and enter the includes: #include #include "account.h"

Coding the server Create Account_impl class, that will execute the business logic

Coding the server Don’t forget the witdraw and balance methods

Coding the server

Excecute the server Observe the account.ior file generated in project folder.

account.ior The ior file have data that represents the remote object location In each execution, a new account.ior file is created, and replace the prior Clients that use the server will need read the account.ior file to locate the remote object

Create the Client 1. The client is another process that use CORBA to communicate with the server 2. Thus, we need create another project to coding the client (in new instance of MS Visual Studio) 3. Create the AccountClient project, and configure it with the instructions few slides ago. Instead of server.cpp, generate the client.cpp file 4. Copy from the server project to the client project the three files: account.cc, account.h and account.ior 5. Add to project only the account.cc and account.h

Create the Client

Execute the client Client´s execution with the server response. If you have communication matters, try copy any time the account.ior file from server project to client project. Note that the client can execute serious times with the same server process

The bootstrapping problem How client obtains the first server´s reference? To solve this problem, server´s information go to client outside the CORBA Framework There are some approachs: File-Based Bootstrapping (used in our example) Naming Service

Naming Service is crucial in distributed applications Examples: java RMI Registry and DNS The Corba Naming Service maps names to Remote Objects Client yet knew where is the Naming Service Naming Server resolve names in references

Naming Service Refactored Example - server In server.cpp file, edit only the header declarations, plus the include, and the main method

Naming Service Refactored Example - server

Naming Service Refactored Example - client

Starting Naming Service 1.Open the command prompty 2.Navigate to the server project directory 3.Enter nsd -ORBIIOPAddr inet:localhost:9001 That start Naming Service on port 9001

Execute the server and the client 1) The server startup 2) The client execution 3) The server execution

Issues Be sure that you understand: How the server and the client acquire the Naming Service reference How server use the Naming Service to bind the Account reference to a name How client acquire the Account remote reference How client use the methods from the Account Remote reference

References Distributed Systems Architecture – Arno Puder at al C++ Programming with CORBA - Andreas Vogel at al Advanced CORBA® Programming with C++ - Michi Henning at al MICO-mail list

Luiz Carlos d´Oleron Graduate in Computer Science, CIn/UFPE Monitor Infra-Estrutura de Software