ACE+TAO Opensource Programming Notes

This book addresses issues related to TAO CORBA development and integration.

First, a word or two about the nature of open source projects. The main benefit of an open source project is that you get a working product you can use, complete with community support. This support often takes the form of user's support as well as developer support. Ideally, these support avenues also include documentation. Should the open source project in question lack some of the pieces mentioned above, its utility as an open source product (particularly as the product becomes more complex) is necessarily diminished.

ACE+TAO is a wonderful product which compares well to other open source products like Orbit or Mico. It encompasses much of the current standard and comes complete with all the services you would expect (and some extras too). Unfortunately, except for the most basic services (the naming service) there are precious few documented programming examples in their tutorial. While there are several source files in the examples directory, these are sadly not written with documented code (often without even a header describing the use for the example), and certainly not included in any web page explaining their code or use.

Object Computing, Inc. freely provides the Getting Started chapter of their TAO Developer's Guide (that can be purchased for around $20.00). This chapter is complete with code examples and walks the user through the steps needed to make a simple TAO client and server. The open-source TAO 1.4a distribution contains all examples referenced in the TAO Developer's Guide, while the FAQ contains some helpful information for beginners and experts alike.

Remedy IT provides freely the CORBA Programmers Guide.

Additionally, the comp.soft-sys.ace and comp.object.corba newsgroups are monitored by groups and individuals able to field questions related to both TAO and CORBA, and the TAO mailing lists are available for questions, discussion, and reporting bugs related to TAO.

The following sections should expand on the single example provided with ACE+TAO (the quoter example) with sections designed to help the user with the event service, the notification service, and other real-time issues. Those reading this page wishing to make contributions in explaining various pieces of the TAO project are encouraged to make contributions to this page.

Build Instructions

The only caveat is that you want to be careful with the "traditional build under a UNIX environment. It treats the install target dir as a sandbox it owns, so if you have chosen /usr/local, like you would with a typical automake project, understand that if there is a problem with the build, the last thing the traditional build env will do is to delete its sandbox (/usr/local).

On the other hand, if you like a no fuss option, Ken Sedgwick over at bonsai.com has provided pre-built RPMs or use the ones provided by Remedy IT from OpenSuSE Build Service (see http://download.opensuse.org/repositories/devel:/libraries:/ACE:/micro). The binaries provided aren't of the debug variety, so they don't take up the shocking amount of space an installation of ACE+TAO build with -g can. The bummer seems to be that the number of compiled in features seems to be a little light. That being said, its certainly a good way to get started, and will handle 90% of your applications.

Build Instructions on Linux

To make installing all of TAO easier use the following script. It will take a lot of time to build so using a script is a good option. The script can also be modified to compile only the necessary TAO features.

#!/bin/bash 
echo "Usage: sudo ./INSTALL-ACE+TAO-6.1.2.sh [INSTALL-DIR]"; 
echo "best to put it in /opt" 
ACETAO=ACE+TAO-6.1.2 
# To change to the latest available install change the ACETAO
# Tested and works with UBUNTU 10.04 and 12.04
if [ $# -eq 1 ]; then 
	INSTALL_DIR=$1; 
	else 
	INSTALL_DIR=~/; 
fi 
# check if script is run as root! 
echo "default run sudo ./INSTALL-ACE+TAO-6.1.2.sh ~/"; 
echo "Tested with Ubuntu-but in theory work on all linux! NJOY !";

# go to $INSTALL_DIR to install ACE+TAO into 
cd $INSTALL_DIR;

# download ACE+TAO to current directory 
echo "Download: wget http://download.dre.vanderbilt.edu/previous_versions/$ACETAO.tar.gz"; 
wget http://download.dre.vanderbilt.edu/previous_versions/$ACETAO.tar.gz 
if [ "$?" -ne 0 ]; then echo "ERROR: download failed!"; exit 1; fi

# rm possible former installation 
rm -rf ACE_wrappers; 
rm -rf $ACETAO;

# extract archive 
echo "UNTAR: tar -xzf $ACETAO.tar.gz"; 
tar -xzf $ACETAO.tar.gz 
if [ "$?" -ne 0 ]; then echo "ERROR: extraction failed!"; exit 1; fi

# set environment variables 
cd ACE_wrappers; 
echo "export ACE_ROOT=$PWD" >> ~/.bashrc 
source ~/.bashrc 
echo 'export TAO_ROOT=$ACE_ROOT/TAO' >> ~/.bashrc 
echo 'export LD_LIBRARY_PATH=$ACE_ROOT/lib:$LD_LIBRARY_PATH' >> ~/.bashrc 
source ~/.bashrc 
cd $ACE_ROOT; 
# create config.h file 
echo "Config.h create--- $ACE_ROOT/ace/config.h" 
echo "#include <ace/config-linux.h>" > $ACE_ROOT/ace/config.h 
echo "" >> $ACE_ROOT/ace/config.h

# create platform_macros.GNU file 
echo "create platform_macros.GNU for linux--$ACE_ROOT/include/makeinclude/platform_macros.GNU"; 
echo "INSTALL_PREFIX = /usr/local" > $ACE_ROOT/include/makeinclude/platform_macros.GNU 
echo "include \$(ACE_ROOT)/include/makeinclude/platform_linux.GNU" >> $ACE_ROOT/include/makeinclude/platform_macros.GNU 
echo "" >> $ACE_ROOT/include/makeinclude/platform_macros.GNU

# compile ace kernel 
cd $ACE_ROOT/ace; 
make; 
if [ "$?" -ne 0 ]; then echo "FAILED to compile $ACE_ROOT/ace!"; exit 1; fi

# compile gperf 
cd $ACE_ROOT/apps/gperf; 
make; 
if [ "$?" -ne 0 ]; then echo "FAILED to compile $ACE_ROOT/apps/gperf!"; exit 1; fi 
 
cd $ACE_ROOT/ace; 
make install; 
if [ "$?" -ne 0 ]; then echo "FAILED to install $ACE_ROOT/ace!"; exit 1; fi

# compile TAO 
cd $TAO_ROOT; 
make; 
if [ "$?" -ne 0 ]; then echo "FAILED to compile $TAO_ROOT/TAO!"; exit 1; fi

echo ""; 
echo "ACE+TAO successfully installed!!!";

Things to check after install

After completing the bulding of the TAO it is important to check if everything is done correctly, Hence run the "tests" available in ACE and TAO to check. If the system is built in Linux then the Naming service is not available by default, but the functionality is provided by tao-cosnaming just like the IDL build is given by tao-idl. you can create a softlink for NamingService with tao_cosnaming by using

ln -s tao_cosnaming Naming_Service

Steps

Run the tests (ACE_wrappers/tests and ACE_wrappers/TAO/tests)
check all the links for the binaries (tao_idl, tao_cosnaming.. etc)
Start with the examples

Present in 2 locations just running then playing around with them is a great start

ACE_wrappers/TAO/DevGuideExamples/ and
ACE_wrappers/TAO/Examples/

Core Development Operations

In this section, the basic tasks which should allow the user to create most CORBA enabled applications are described.

Services

The following sections describe the various services, their configuration, and, if not covered above, should include an example.