DDS_DiscoveryQosPolicy Struct Reference

<<cert>> Specifies the attributes required to discover participants in the domain. More...

#include <dds_c_domain.h>

Data Fields
struct DDS_StringSeq	initial_peers
	Determines the initial list of peers that will be contacted by the Discovery mechanism to send announcements about the presence of this participant.
struct DDS_StringSeq	enabled_transports
	The transports available for use by the Discovery mechanism.
struct DDS_DiscoveryComponent	discovery
	The name of the discovery plugin that will be used to create a discovery plugin for this DDS_DomainParticipant.
DDS_Boolean	accept_unknown_peers
	Whether to accept a new participant that is not in the initial peer list.

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Detailed Description

<<cert>> Specifies the attributes required to discover participants in the domain.

Entity:

DDS_DomainParticipant

Properties:

RxO = N/A
Changeable = NO

Usage

This extended Qos is used to define how participants find each other on a network.

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Field Documentation

struct DDS_StringSeq DDS_DiscoveryQosPolicy::initial_peers

Determines the initial list of peers that will be contacted by the Discovery mechanism to send announcements about the presence of this participant.

If there is a remote peer DDS_DomainParticipant such as is described this list, it will become aware of this participant and will engage in the Discovery protocol to exchange meta-data with this participant.

Each element of this list must be a peer descriptor in the proper format.

[default] Empty sequence

[range] Sequence of arbitrary length.

struct DDS_StringSeq DDS_DiscoveryQosPolicy::enabled_transports

The transports available for use by the Discovery mechanism.

Only these transports can be used by the discovery mechanism to send meta-traffic via the builtin endpoints (built-in DDS_DataReader and DDS_DataWriter).

Also determines the unicast addresses on which the Discovery mechanism will listen for meta-traffic. These along with the domain_id and participant_id determine the unicast locators on which the Discovery mechanism can receive meta-data.

The memory for the strings in this sequence is managed according to the conventions described in Conventions. In particular, be careful to avoid a situation in which RTI Connext DDS Micro allocates a string on your behalf and you then reuse that string in such a way that RTI Connext DDS Micro believes it to have more memory allocated to it than it actually does.

[default] Empty sequence.

When an empty sequence is passed to DDS_DomainParticipantFactory_create_participant in the DDS_DomainParticipantQos, the domain participant will automatically add the following locators to listen for discovery traffic on: "_udp://", "_udp://127.0.0.1", and "_udp://239.255.0".

[range] Sequence of non-null,non-empty strings.

struct DDS_DiscoveryComponent DDS_DiscoveryQosPolicy::discovery

The name of the discovery plugin that will be used to create a discovery plugin for this DDS_DomainParticipant.

The DDS_DomainParticipantFactory will search through a list of registered discovery plugins. If it finds a registered discovery factory with a name matching this factory name, it will use that discovery plugin to create a new instance of the discovery plugin and register the plugin with the DDS_DomainParticipant.

If it does not find a registered discovery factory with this name, it will return DDS_RETCODE_PRECONDITION_NOT_MET

Precondition:

One or more discovery plugins must have been previously registered with the DDS_DomainParticipantFactory, each with an associated name.

DDS_Boolean DDS_DiscoveryQosPolicy::accept_unknown_peers

Whether to accept a new participant that is not in the initial peer list.

If DDS_BOOLEAN_FALSE, the participant will only communicate with those in the initial peer list

If DDS_BOOLEAN_TRUE, the participant will also communicate with all discovered remote participants.

[default] DDS_BOOLEAN_TRUE