DDS Entities
============

The main classes extend an abstract base class called a DDS *Entity*. Every DDS *Entity* has a 
set of associated events known as statuses and a set of associated Quality of Service Policies 
(QosPolicies). In addition, a *Listener* may be registered with the *Entity* to be called when 
status changes occur. DDS *Entities* may also have attached DDS *Conditions*, which provide a way 
to wait for status changes. `Figure 4.1: Overview of DDS Entities`_ presents an overview in a UML 
diagram.

.. _`Figure 4.1: Overview of DDS Entities`:

.. figure:: ../images/EntitiesUML.png

   Overview of DDS Entities

Please note that |rti_me| does not support the following:

- **MultiTopic**
- **ContentFilteredTopic**
- **ReadCondition**
- **QueryConditions**

For a general description of DDS *Entities* and their operations, please refer to 
|rti_core_um_entities_verbose| in the |rti_core_um| (available |rti_core_um_entities|_ 
if you have Internet access). Note that |rti_me| does not support 
all APIs and QosPolicies; please refer to the |api_ref_c|_ and |api_ref_cpp|_ documentation 
for more information.