DomainParticipantFactory

• C, Traditional C++, Java and .NET APIs:

The main purpose of a DomainParticipantFactory is to create and destroy DomainParticipants.

In C++ terms, this is a singleton class; that is, you will only have a single DomainParticipantFactory in an application—no matter how many DomainParticipants the application may create. Figure 3 shows how to instantiate a DomainParticipantFactory. Notice that there are no parameters to specify. Alternatively, in C++, C++/CLI, and C#, the predefined macro, DDSTheParticipantFactory,1In C, the macro is DDS_TheParticipantFactory. In Java, use the static class method DomainParticipantFactory.TheParticipantFactory. can also be used to retrieve the singleton factory.

Unlike the other Entities that you create, the DomainParticipantFactory does not have an associated Listener. However, it does have associated QosPolicies, see Setting DomainParticipantFactory QosPolicies. You can change them using the factory’s get_qos() and set_qos() operations. The DomainParticipantFactory also stores the default QoS settings that can be used when a DomainParticipant is created. These default settings can be changed as well, see Getting and Setting Default QoS for Child Entities.

Figure 3 Instantiating a DomainParticipantFactory

DDSDomainParticipantFactory* factory = NULL;
factory = DDSDomainParticipantFactory::get_instance();
if (factory == NULL) {
	// ... error
}

• Modern C++ API:

In the Modern C++ API, there isn’t a explicit DomainParticipantFactory. DomainParticipants are created using their constructors andare automatically destroyed as a reference type (See Creating and Deleting DDS Entities).

The operations to set and get the default DomainParticipantQos are static functions in DomainParticipant: DomainParticipant::default_participant_qos(). The operations to look up participants are freestanding functions in the dds::domain and rti::domain namespaces: dds::domain::find(), rti::domain::find_participant_by_name(), and rti::domain::find_participants(). The class QosProvider is responsible for managing QoS profiles (see How to Load XML-Specified QoS Settings).

There is a DomainParticipantFactoryQos, but it only contains the ENTITY_FACTORY to indicate if a DomainParticipant should be enabled in its constructor or by calling enable(), and SYSTEM_RESOURCE_LIMITS. The DomainParticipantFactoryQos getter and setter are static functions in DomainParticipant: DomainParticipant::participant_factory_qos().

Another static function in DomainParticipant allows finalizing the implicit DomainParticipantFactory singleton: DomainParticipant::finalize_participant_factory().

Once you have a DomainParticipantFactory, you can use it to perform the operations listed in Table 1 . The most important one is create_participant(), described in Creating a DomainParticipant. For more details on all operations, see the API Reference HTML documentation as well as the section of the manual listed in the Reference column.

Table 1 DomainParticipantFactory Operations

Working with ...	Operation	Description	Reference
Domain-Participants	create_participant	Creates a DomainParticipant.	Creating a DomainParticipant
	create_participant_with_ profile	Creates a DomainParticipant based on a QoS profile.
	delete_participant	Deletes a DomainParticipant.	Deleting DomainParticipants
	get_default_participant_qos	Gets the default QoS for DomainParticipants.	Getting and Setting Default QoS for DomainParticipants
	get_participants	Returns a sequence of pointers to all the DomainParticipants within the DomainParticipantFactory.	Looking Up DomainParticipants
	lookup_participant	Finds a specific DomainParticipant, based on a domain ID.
	lookup_participant_by_name	Finds a specific DomainParticipant, based on a domain name.
	set_default_participant_qos	Sets the default QoS for DomainParticipants.	Getting and Setting Default QoS for DomainParticipants
	set_default_participant_qos_ with_profile	Sets the default QoS for DomainParticipants based on a QoS profile.
The Factory’s Instance	get_instance	Gets the singleton instance of this class.	Freeing Resources Used by the DomainParticipantFactory
	finalize_instance	Destroys the singleton instance of this class.
The Factory’s Own QoS	get_qos	Gets/sets the DomainParticipantFactory’s QoS.	Getting, Setting, and Comparing QosPolicies
	set_qos
	equals	Compares two DomainParticipantFactory’s QoS structures for equality.
Threads	set_thread_factory	Specifies a ThreadFactory implementation that DomainParticipants will use to create and delete all threads.	User-Managed Threads
	unregister_thread	Frees all resources related to a thread. This function is intended to be used at the end of any user-created threads that invoke Connext DDS APIs (not all users will have this situation). The best approach is to call it immediately before exiting such a thread, after all Connext DDS APIs have been called.
Profiles & Libraries	get_default_library	Gets the default library for a DomainParticipantFactory.	Getting and Setting the DomainParticipantFactory’s Default QoS Profile and Library
	get_default_profile	Gets the default QoS profile for a DomainParticipantFactory.
	get_default_profile_library	Gets the library that contains the default QoS profile for a DomainParticipantFactory.
	get_<entity>_qos_from_profile	Gets the <entity> QoS values associated with a specified QoS profile. <entity> may be topic, datareader, datawriter, subscriber, publisher, or participant.	Getting QoS Values from a QoS Profile
	get_<entity>_qos_from_profile_w_topic_name	Like get_<entity>_qos_from_profile(), but this operation allows you to specify a topic name associated with the entity. The topic filter expressions in the profile will be evaluated on the topic name. <entity> may be topic, datareader, or datawriter.
	get_qos_profiles	Gets the names of all XML QoS profiles associated with a specified XML QoS profile library.	Configuring QoS with XML
	get_qos_profile_libraries	Gets the names of all XML QoS profile libraries associated with the DomainParticipantFactory.	Retrieving a List of Available Libraries
	load_profiles	Explicitly loads or reloads the QoS profiles.	Loading, Reloading and Unloading Profiles
	reload_profiles
	set_default_profile	Sets the default QoS profile for a DomainParticipantFactory.	Getting and Setting the DomainParticipantFactory’s Default QoS Profile and Library
	set_default_library	Sets the default library for a DomainParticipantFactory.
	unload_profiles	Frees the resources associated with loading QoS profiles.	Loading, Reloading and Unloading Profiles

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