Build CORBA Applications with C , MICO and Win32

1
Build CORBA Applications with C, MICO and Win32

• Luiz Carlos dOleron
• lcadb_at_cin.ufpe.br

http//www.cin.ufpe.br/if677
2
Acknowlegdes

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

3
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 !

4
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

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Whats MICO

• MICO is CORBA!
• Micro CORBA
• A Implementation of CORBA specification subset
• With him you can write CORBA applications in C
  or Java
• Visit http//www.mico.org

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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 http//www.cin.ufpe.br/if677/monitori
  a/corba

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Configure Visual Studio Project
1) File -gtNew-gtProject 2) Expand Visual C
Projects 3) Select Win32 Folder
4) Select Win32 Console Project 5) Enter a Name
to Project 6) Click OK
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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
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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
?
?
?
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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 OpenD
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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.
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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
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Create and Compile the IDL File

• Create the account.idl text file in project
  folder
• Open the cmd (start-gtrun enter cmd)
• Go to project folder
• 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

• interface Account
• void deposit(in long amount)
• void withdraw(in long amount)
• long balance()

account.idl
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Additional Tasks
Hei, in account.cc file, change the include
ltaccount.hgt to account.h
Do you remember the server.cpp file? Open and
enter the includes include ltiostreamgt include
ltfstreamgt include "account.h"
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Coding the server
Create Account_impl class, that will execute the
business logic
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Coding the server
Dont forget the witdraw and balance methods
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Coding the server
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Coding the server
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Excecute the server
Observe the account.ior file generated in project
folder.
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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

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Create the Client

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

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Create the Client
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Create the Client
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Execute the client
Clients 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
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The bootstrapping problem

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

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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

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Naming Service Refactored Example - server
In server.cpp file, edit only the header
declarations, plus the ltcoss/CosNaming.hgt
include, and the main method
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Naming Service Refactored Example - server
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Naming Service Refactored Example - server
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Naming Service Refactored Example - client
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Naming Service Refactored Example - client
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Starting Naming Service

• Open the command prompty
• Navigate to the server project directory
• Enter
• nsd -ORBIIOPAddr inetlocalhost9001
• That start Naming Service on port 9001

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

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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
• www.mico.org

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Luiz Carlos dOleron

• Graduate in Computer Science, CIn/UFPEhttp//www.
  cin.ufpe.br
• Monitor Infra-Estrutura de Software
  http//www.cin.ufpe.br/if677