Adapting Data Sources

The data source integrates the orchestrator, and must instantiate it and provide a ROS node for it. The ROS node must not be shared with functionality of the data source, which usually results in 2 ROS nodes being instantiated in the data source. Both nodes may be executed by the same executor, which must also be provided to the orchestrator to enable it to process inputs while waiting for events.

The following changes need to be made:

• Call Orchestrator.initialize_ros_communication() once the data source’s own publishers and subscribers are set up.

• Call Orchestrator.wait_until_publish_allowed() before publishing any message, and wait until the returned Future is ready before publishing. This does not apply to messages on the /clock topic.

• Call Orchestrator.wait_until_time_publish_allowed() with the specific message before publishing it on /clock, and wait until the returned Future is ready before publishing.

• Call Orchestrator.wait_until_dataprovider_state_update_allowed() and wait until the returned Future is ready before changing internal state, such as by executing a simulation timestep which may depend on external inputs.

• Call Orchestrator.wait_until_pending_actions_complete() before exiting.

Orchestrator Class Reference