TAO's CORBA Object Services Directory Hierarchy

The file and directory organization for TAO services can be confusing at first glance (and even on subsequent ones to be honest), so we felt like some rationale and explanation of the directory hierarchy was needed.

For general sanity all TAO services files are located under $TAO_ROOT/orbsvcs.

It is expected that clients use more than one service at the same time (in fact some of the services already do, for instance the Event Service uses the Naming Service and the Scheduling Service). For this reason all the services stubs are grouped in one library. This library is located in $TAO_ROOT/orbsvcs/orbsvcs. Usually the include path is only $TAO_ROOT/orbsvcs, so files are included like this:

#include "orbsvcs/CosNamingC.h"

To simplify the IDL generation the skeletons are also on the library, this is not a problem for client programs and most services need to link the library anyway (since they use other services.) Further, the current support for collocation requires that clients link the skeleton files anyway.

In the future we intend to use ACE Service Configurator to give the users control over collocation of the services implementation. As a first cut all the service implementations are included in the orbsvcs library $TAO_ROOT/orbsvcs/orbsvcs. Since there are serveral services and each one is implemented using several files we have given a different directory to each service. This structure could also simplify a future split into several libraries (if it proves necessary).

The complete list of directories is:

Service Implementation Sub-directory
A/V Streams Serviceorbsvcs/AV
Concurrency Serviceorbsvcs/Concurrency
Event Serviceorbsvcs/CosEvent
Real-time Event Serviceorbsvcs/Event
LifeCycle Serviceorbsvcs/LifeCycle
Load Balancing Service orbsvcs/LoadBalancing
Logging Serviceorbsvcs/Log
Naming Serviceorbsvcs/Naming
Property Serviceorbsvcs/Property
Scheduling Serviceorbsvcs/Sched
Security Service orbsvcs/Security
SSLIOP Pluggable Protocol orbsvcs/SSLIOP
Trading Serviceorbsvcs/Trader
Time Serviceorbsvcs/Time
Notification Serviceorbsvcs/Notify

Note that in the current version of TAO we still have standalone binaries for some of the services. However, some applications may want to control what process implements a particular service. Therefore, it has proved useful for debugging purposes to keep the most used services separated. The binaries in question are located in $TAO_ROOT/orbsvcs, and the list includes:

In the future we plan to use a single binary and ACE Service Configurator and keep a single binary.

The Implementation Repository is a unique service in that it starts server executables, and it doesn't make sense to collocate it in another server. Because of this, only the IDL files are located in $TAO_ROOT/orbsvcs/orbsvcs. The other files are all located in $TAO_ROOT/orbsvcs/ImplRepo_Service.

Finally the tests and example programs are located in $TAO_ROOT/orbsvcs/tests; once more each may involve more than a single binary, so each one is kept in its own directory; the following list describes the contents of each one:

Test directory Purpose
AVStreams A complete A/V server and client.
Concurrency Test the Concurrency Service.
CosEC_Basic Test the basic functionality of the standard Event Service.
CosEC_Multiple Simple example that connects multiple consumers and/or suppliers to the standard event service. It can be used to show how composing a standard event-service and the real-time event service provides filtering capabilities.
Event Test the functionality of the real-time Event Service.
EC_Custom_Marshal Show how the Real-time event service can send user defined data using custom marshaling.
EC_Mcast Multiple real-time event channels can communicate using multicast, this example shows how to do it.
EC_Multiple Connect two Real-time Event Channels using the EC_Gateway, measure latency, utilization and minimum spacing.
EC_Throughput Measure throughput and latency for collocated and remote real-time event services.
ImplRepo Tests used to test the functionality of the Implementation Repository Service.
LoadBalancing Test that exercises the Load Balancing service.
Logger An example logging service using the Naming Service to locate a factory.
Naming This is an obsolete directory.
Property Testing for the Property Service.
Sched A test of the Scheduling Service.
Security Tests that verify that the Security Service is functioning properly. Tests for auxiliary Security Service components such as the SSLIOP pluggable protocol also exist in this directory.
Simple_Naming A number of Naming Service tests: from very simple to more fancy.
Simulator Prototype implementation of DOVE (DOVE Agent, DOVE Browser, DOVE MIB, DOVE Application). The DOVE Agent consists of the Event Channel, which is then connected to a DOVE Browser implemented in Java.
Trading Tests for the Trading Service.
Time A test for the Time Service.
Notify Consists of basic tests foe the Notification Service - Simple event transfer, client Connect-Disconnect to event channel, creating and destroying channel/admin objects,test for Admin properties, test to check offer/subscription changes. The directory also has performance tests for throughput.

SEE ALSO

You may you to check TAO release notes for up to date information on status, changes, future work, etc.

Carlos O'Ryan