CIAO application

Display example README

To download the code of this example please refer to the CVS repository at $CIAO_ROOT/DAnCE/examples/Display.

Example Description

This example is an imaginary car (software) instrument assembly which updates the display of current coordination of the airplane periodically. It consists of the following three components:

The RateGen component sends periodic Pulse events to consumers according to the rate specified in its attribute Rate, it allows a client (CORBA client controller) to start and stop the rate generating event.
The GPS component interacts with a GPS hardware. When the GPS component receives Refresh events from RateGen, it queries the GPS hardware and updates the internal cached coordination (so that the current location can be read by accessing the MyLocation interface) and generates an event on its Ready port to inform the event consumers that a new GPS reading is available.
The NavDisplay component displays the current location of the vehicle on the windshield. When a NavDisplay receives an event notifying the availability of new data on its Refresh port, it will acquire the current location of the vehicle by querying the interface connected to the GPSLocation receptacle.
The NavDisplayGUI directory contains implementations for a NavDisplay with graphical interface. To use this graphical interface you need to install qt libraries and have qt enabled (qt = 1) in your $ACE_ROOT/bin/MakeProjectCreator/config/global.features. In some Linux distributions qt is installed by default. There is a non-commercial version of qt libraries for Windows here and more information about qt here.
If you just want to run the application, just go to the last section of this page.

The files you will find.

1. The interfaces, data types and exceptions used by the components of this application are specified in the


HUDisplay.idl

file, placed in this example root directory ($CIAO_ROOT/examples/Display). This is a IDL2 file and uses the familiar CORBA data types. The lib generated from HUDisplay.idl is linked to all the components of this example.

2. mpc files for each of the components are available in the components directories. We use the MPC to generate makefiles and Visual C++ project/solutions files for all ACE, TAO and CIAO libraries.

3. idl and cidl files for each component are placed in components directory.

4. The _exec.h and _exec.cpp files are the actual implementation of the components.

5. The NavDisplayGUI_exec directory: The NavDisplayGUI_exec.cpp is just an executor version for NavDisplay. In NavDisplayGUI_exec directory you'll find only the the NavDisplayGUI_exec (and files for the GUI), which can be deployed with the NavDisplay stub and servant. So, if you deploy the NavDisplay component using NavDisplay_exec you'll be able to see the application running in the shell you triggered the NodeDaemon, and if you deploy the NavDisplay component using NavDisplayGUI_exec a graphical interface will show you a red dot moving over a map according to the location being generated by GPS component when you start the application. Notice that the NavDisplayGUI.mpc file includes qt, used for graphical interface. You must give the right location of qt libraries in your mpc file.

6. The controller: The RateGencomponent is started and stopped by the controller, a CORBA client application. The controller source is in RateGen directory, so the RateGen.mpc file also include instructions for the controller build.

Make

Go to the directory $CIAO_ROOT/DAnCE/examples/Display and do:
$ACE_ROOT/bin/mwc.pl (use -type option if you are using a compiler/IDE other than gnuace -which by default generates GNU makefiles)

For example, using $ACE_ROOT/bin/mwc.pl -type vc71 if you are using Visual C++ 7.1 IDE.

Assemble

Now we can step forward to build the assembly.

In the descriptor subdirectory, you'll find a XML descriptor file that describes your deployment plan, the flattened_deploymentplan.cdp:

This file declaratively specifies how the component assembly is constructed. Specifically, it specifies the component types, component instances, component connections and implementation artifact descriptions.

Please make sure that the Modified_Deployment.xsd and XMI.xsd files are in the Display/descriptors directory. The former file could be found in $CIAO_ROOT/docs/schema directory.

Note: Creating the deployment plan descriptor is a tedious and error-prone job, you can download CoSMIC to assist you in this step.

Run

Finally you are ready to test the application you have made. From different shells in $CIAO_ROOT/DAnCE/examples/Display/descriptors/ directory:

Start NodeManagers (NodeDameon) by running basicNodeDaemons.pl
Start the execution manager: $CIAO_ROOT/DAnCE/ExecutionManager/Execution_Manager -o EM.ior -i NodeManagerMap.dat The NodeManagerMap.dat file describes the deployment daemons CIAO's Execution_Manager will contact to instantiate ComponentServer's, home's, and component instances. Each line specify the name of a installation "destination" and the corresponding IOR for the CIAO_Daemon. For example, the NodeManagerMap.dat contains: AirFrameDevice corbaloc:iiop:localhost:10000/NodeManager TimerDevice corbaloc:iiop:localhost:12000/NodeManager You can copy and modify the copy to deploy the components in various different locations to let the application truely "distributed". Remember to start up the Execution_Manager using the revised .dat file you created, and start up the CIAO_Daemon according to the specification.

NOTE: As one can see, we use the "NodeManagerMap.dat" file to instruct the Execution_Manager how to find the endpoint of each individual NodeManager (i.e., Node Daemon) where component(s) will be deployed, so this is non-standard. We plan to use Naming Service to do this in the future.

Start the plan_launcher: $CIAO_ROOT/DAnCE/Plan_Launcher/plan_launcher -p flattened_deploymentplan.cdp -k file://EM.ior After this, components should be deployed successfully.
The Assembly_Manager is instructed to write the IOR of the RateGen component to a file called "rategen.ior" in this directory. You will then need to use a controller program in a separate shell window to switch on/off the Rate Generator. Go to the $CIAO_ROOT/DAnCE/examples/Display/descriptor directory and run the $CIAO_ROOT/DAnCE/examples/Display/RateGen/controller -o to start the application. To stop the application run $CIAO_ROOT/DAnCE/examples/Display/RateGen/controller -f

Email:

ciao-users@cse.wustl.edu