EXAMPLES

RoundTrip

1) Description

The Roundtrip example allows the measurement of roundtrip duration when sending and receiving back a single message.

2) Design

It consists of 2 units :

3) Scenario

A message is sent by the ping executable on the "PING" partition, which the pong executable is waiting for. The pong executable sends the same message back on the "PONG" partition, which the ping executable is waiting for. This sequence is repeated a configurable number of times.

The ping executable measures:

Configurable:

Running of examples in Standalone Mode

Running the examples in a Posix environment

Environment Setup

Let's call OpenSplice_install_dir the OpenSplice installation directory.

The OpenSpliceDDS environment variables must be set in order for the examples to build/run correctly. To do this, open a terminal and source the "OpenSplice_install_dir/release.com" script supplied with the distribution.

C, C++ and ISO C++ Executables

Building the examples is described on the Summary page

Two executables and a two libraries are generated in the example directory when the example is built:

For ISO C++

For C++

For C

Running the example

Ensure that the environment for OpenSpliceDDS is set up correctly as described above for each new terminal used. If running the C, C++ or ISO C++ examples, ensure that . is added to the LD_LIBRARY_PATH.

It is recommended that you run the subscriber and publisher in separate terminals to avoid mixing the output

Running in single process (heap memory) configuration : the application starts OpenSpliceDDS middleware

Running in multiple process shared memory configuration

To enable deployment in this mode, an OpenSpliceDDS configuration file must be selected that has shared memory support e.g. one of the ospl_shmem xml configuration files found in the OpenSplice_install_dir/etc/config directory.

Starting ping and pong

In the first terminal start pong by running the pong executable

    pong usage:
      ./pong
    

In the second terminal start ping by the ping executable

    ping usage (parameters must be supplied in order):
      ./ping [payloadSize (bytes, 0 - 655536)] [numSamples (0 = infinite)] [timeOut (seconds, 0 = infinite)]
      ./ping quit - ping sends a quit signal to pong.
    defaults:
      ./ping 0 0 0
    

To achieve optimal performance it is recommended to set the CPU affinity so that ping and pong run on separate CPU cores. You must have su privileges to run the following commands.

    pong usage:
      taskset -c 0 chrt -f 80 ./pong
    ping usage:
      taskset -c 1 chrt -f 80 ./ping [payloadSize (bytes, 0 - 655536)] [numSamples (0 = infinite)] [timeOut (seconds, 0 = infinite)]
    

Running C/C++/ISO C++ on Windows

Environment Setup

Let's call OpenSplice_install_dir the OpenSplice installation directory.

The OpenSpliceDDS environment variables must be set in order for the examples to run correctly. To do this open an OpenSpliceDDS Command Prompt which will set up the environment variables for OpenSpliceDDS automatically. The OpenSpliceDDS Command Prompt can be selected from the start menu. Alternatively, open a windows Command Prompt and execute the "OpenSplice_install_dir\release.bat" batch script supplied with the distribution.

C/C++/ISO C++

Building the examples is described on the Summary page

Two executables are generated in the example directory when the example is built:

For C, C++ and C#

Running the C/C++/ISO C++ Examples

Ensure that the environment for OpenSpliceDDS is set up correctly as described above for each new command prompt used.

The following steps describe how to run the examples:

Running in single process (heap memory) configuration : the application starts OpenSpliceDDS middleware

Running in multiple process shared memory configuration

To enable deployment in this mode, an OpenSpliceDDS configuration file must be selected that has shared memory support e.g. one of the ospl_shmem xml configuration files found in the OpenSplice_install_dir\etc\config directory.

In the first terminal start pong by running the pong executable

    pong usage:
      pong.exe
    

In the second terminal start ping by the ping executable

    ping usage (parameters must be supplied in order):
      ./ping [payloadSize (bytes, 0 - 655536)] [numSamples (0 = infinite)] [timeOut (seconds, 0 = infinite)]
      ./ping quit - ping sends a quit signal to pong.
    defaults:
      ./ping 0 0 0
    

To achieve optimal performance it is recommended to set the CPU affinity so that ping and pong run on separate CPU cores

    pong usage:
      START /affinity 1 /high cmd /k "pong.exe"
    ping usage:
      START /affinity 2 /high cmd /k "ping.exe" [payloadSize (bytes, 0 - 655536)] [numSamples (0 = infinite)] [timeOut (seconds, 0 = infinite)]