DCPS Examples

The examples source code can be found in the examples folder of your OpenSplice installation. The descriptions below summarize what each example demonstrates. Towards the bottom of the page you will find instructions on how to build and run the examples.

Tutorial

This example is a good starting point as it provides an overview of how to use the most commonly used features of the API to make a message board application.
Example Description.

HelloWorld

This is a simple publisher and subscriber example. One sample is published, the sample is then read. Some non-default QoS are used to guarantee delivery and to allow the publisher to be optionally run before the subscriber.
Example Description.

ContentFilteredTopic

In this example a ContentFilteredTopic is used to filter the messages received by the subscriber to be only those with a ticket equal to the one supplied as a parameter to the program. Some non-default QoS are used to guarantee delivery.
Example Description.

Durability

This example demonstrates the two kinds of durability, transient and persistent and allows the user to specify which durability kind is used.
Example Description.

Listener

In this example a listener is registered on the datareader of the subscriber which listens for the receipt of a message from the publisher and handles it. Some non-default QoS are used to guarantee delivery and to allow the publisher to be optionally run before the subscriber.
Example Description.

Lifecycle

This is example demonstrates the changes in Lifecycle states when a DataWriter is reated, sends samples or is deleted.
Example Description.

Ownership

This example demonstrates the Ownership QoS. The subscriber will read messages sent by the publishers and display those with the highest ownership strength.
Example Description.

QueryCondition

This is a reasonably simple case publisher and subscriber example. One sample is published, the sample is then read. Some non-default QoS are used to guarantee delivery and to allow the publisher to be optionally run before the subscriber.
Example Description.

RoundTrip

The RoundTrip example consists of a Ping and a Pong application. Ping sends samples to Pong by writing to the Ping partition which Pong subscribes to. Pong them sends them back to Ping by writing on the Pong partition which Ping subscribes to. Ping measures the amount of time taken to write and read each sample as well as the total round trip time to send a sample to Pong and receive it back.
Example Description.

Throughput

The Throughput example measures data throughput in bytes per second. The publisher allows you to specify a payload size in bytes as well as allowing you to specify whether to send data in bursts. The publisher will continue to send data forever unless a time out is specified. The subscriber will receive data and output the total amount received and the data rate in bytes per second. It will also indicate if any samples were received out of order. A maximum number of cycles can be specified and once this has been reached the subscriber will terminate and output totals and averages.
Example Description.

WaitSet

This example demonstrates how a WaitSet can be used to wait on certain conditions which will then trigger a corresponding handler functor to perform any actions required such as reading data.
Example Description.

BuiltinTopics

This example demonstrates the use of builtin topics by monitoring the number of nodes that participate in a DDS domain.
Example Description.

Building in a POSIX environment with make

In the following sections $OSPL_HOME identifies the installation directory of OpenSplice. Note it is not however required that this be exported as a variable in the shell environment.

Building a single example

Change directory to the example source directory and make. E.g.:

$ cd $OSPL_HOME/examples/dcps/HelloWorld/isocpp
$ make

Building all examples

The top-level makefile Makefile.DCPS_ISO_CPlusPlus can be used to build all the examples.

$ cd $OSPL_HOME/examples
$ make -f Makefile.DCPS_ISO_CPlusPlus

Building on Windows with Visual Studio

A link is installed on the Windows Start Menu in the Examples Folder under the OpenSplice HDE folder. Alternately: navigate to the \examples folder in the OpenSplice HDE installation with Windows Explorer or the Visual Studio file -> open dialogue and open the solution file DCPS_ISO_CPlusPlus.sln.

Running examples

The environment property OSPL_URI can set to indicate the location of a local domain configuration file. If this variable is not set, or is set to point to a file that specifies a shared memory domain configuration, the command ospl start must be used to start the domain before an example can be run.

The default configuration file installed by the distribution uses single process (i.e. heap memory) mode so this is not required.

POSIX:

In the following examples $OSPL_HOME identifies the installation directory of OpenSplice. Note it is not however required that this be exported as a variable in the shell environment.

A script release.com is provided. It exports a value of OSPL_URI to indicate the file $OSPL_HOME/etc/config/ospl.xml and also makes the OpenSplice libraries available on the library load path.

To run an example in single process mode:

$ cd $OSPL_HOME
$ ./release.com
$ cd examples/isocpp/HelloWorld/isocpp
$ subscriber &
$ publisher

To run an exmaple in shared memory mode you might do:

$ cd $OSPL_HOME
$ ./release.com
$ OSPL_URI=file://$OSPL_HOME/etc/config/ospl_shmem_ddsi.xml
$ export OSPL_URI
$ cd examples/isocpp/HelloWorld/isocpp
$ ospl start
$ subscriber &
$ publisher
$ ospl stop

Windows:

In the following examples %OSPL_HOME% identifies the installation directory of OpenSplice. Note it is not however required that this be set as a variable in the console environment.

A script release.bat is provided. It exports a value of OSPL_URI to indicate the file %OSPL_HOME%\etc\config\ospl.xml and also makes the OpenSplice executables and dynamic-link libraries available on the PATH.

A shortcut within the OpenSplice HDE folder on the Start Menu: Vortex OpenSplice command prompt creates a cmd.exe console session with this environment ready set.