Exemple #1
0
int
OSPL_MAIN (
    int argc,
    char *argv[])
{
    /* Generic DDS entities */
    DomainParticipantFactory_var    dpf;
    DomainParticipant_var           participant;
    Topic_var                       chatMessageTopic;
    Subscriber_var                  chatSubscriber;
    DataReader_ptr                  parentReader;

    /* Type-specific DDS entities */
    ChatMessageTypeSupport_var      chatMessageTS;
    ChatMessageDataReader_var       chatAdmin;
    ChatMessageSeq_var              msgSeq = new ChatMessageSeq();
    SampleInfoSeq_var               infoSeq = new SampleInfoSeq();

    /* QosPolicy holders */
    TopicQos                        reliable_topic_qos;
    SubscriberQos                   sub_qos;
    DDS::StringSeq                  parameterList;

    /* DDS Identifiers */
    DomainId_t                      domain = 0;
    ReturnCode_t                    status;

    /* Others */
    bool                            terminated = false;
    const char *                    partitionName = "ChatRoom1";
    char  *                         chatMessageTypeName = NULL;

    /* Options: MessageBoard [ownID] */
    /* Messages having owner ownID will be ignored */
    parameterList.length(1);

    if (argc > 1) {
        parameterList[0] = string_dup(argv[1]);
    }
    else
    {
        parameterList[0] = "0";
    }

    /* Create a DomainParticipantFactory and a DomainParticipant (using Default QoS settings. */
    dpf = DomainParticipantFactory::get_instance();
    checkHandle(dpf.in(), "DDS::DomainParticipantFactory::get_instance");
    participant = dpf->create_participant (
        domain,
        PARTICIPANT_QOS_DEFAULT,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(participant, "DDS::DomainParticipantFactory::create_participant");

    /* Register the required datatype for ChatMessage. */
    chatMessageTS = new ChatMessageTypeSupport();
    checkHandle(chatMessageTS.in(), "new ChatMessageTypeSupport");
    chatMessageTypeName = chatMessageTS->get_type_name();
    status = chatMessageTS->register_type(
        participant.in(),
        chatMessageTypeName);
    checkStatus(status, "NetworkPartitionsData::ChatMessageTypeSupport::register_type");

    /* Set the ReliabilityQosPolicy to RELIABLE. */
    status = participant->get_default_topic_qos(reliable_topic_qos);
    checkStatus(status, "DDS::DomainParticipant::get_default_topic_qos");
    reliable_topic_qos.reliability.kind = DDS::RELIABLE_RELIABILITY_QOS;

    /* Make the tailored QoS the new default. */
    status = participant->set_default_topic_qos(reliable_topic_qos);
    checkStatus(status, "DDS::DomainParticipant::set_default_topic_qos");

    /* Use the changed policy when defining the ChatMessage topic */
    chatMessageTopic = participant->create_topic(
        "Chat_ChatMessage",
        chatMessageTypeName,
        reliable_topic_qos,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(chatMessageTopic.in(), "DDS::DomainParticipant::create_topic (ChatMessage)");

    /* Adapt the default SubscriberQos to read from the "ChatRoom1" Partition. */
    status = participant->get_default_subscriber_qos (sub_qos);
    checkStatus(status, "DDS::DomainParticipant::get_default_subscriber_qos");
    sub_qos.partition.name.length(1);
    sub_qos.partition.name[0] = partitionName;

    /* Create a Subscriber for the MessageBoard application. */
    chatSubscriber = participant->create_subscriber(sub_qos, NULL, STATUS_MASK_NONE);
    checkHandle(chatSubscriber.in(), "DDS::DomainParticipant::create_subscriber");

    /* Create a DataReader for the NamedMessage Topic (using the appropriate QoS). */
    parentReader = chatSubscriber->create_datareader(
        chatMessageTopic.in(),
        DATAREADER_QOS_USE_TOPIC_QOS,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(parentReader, "DDS::Subscriber::create_datareader");

    /* Narrow the abstract parent into its typed representative. */
    chatAdmin = ChatMessageDataReader::_narrow(parentReader);
    checkHandle(chatAdmin.in(), "NetworkPartitionsData::ChatMessageDataReader::_narrow");

    /* Print a message that the MessageBoard has opened. */
    cout << "MessageBoard has opened: send a ChatMessage with userID = -1 to close it...." << endl << endl;

    while (!terminated) {
        /* Note: using read does not remove the samples from
           unregistered instances from the DataReader. This means
           that the DataRase would use more and more resources.
           That's why we use take here instead. */

        status = chatAdmin->take(
            msgSeq,
            infoSeq,
            LENGTH_UNLIMITED,
            ANY_SAMPLE_STATE,
            ANY_VIEW_STATE,
            ALIVE_INSTANCE_STATE );
        checkStatus(status, "NetworkPartitionsData::ChatMessageDataReader::take");

        for (ULong i = 0; i < msgSeq->length(); i++) {
            ChatMessage *msg = &(msgSeq[i]);
            if (msg->userID == TERMINATION_MESSAGE) {
                cout << "Termination message received: exiting..." << endl;
                terminated = true;
            } else {
                cout << msg->userID << ": " << msg->content << endl;
            }
        }

        status = chatAdmin->return_loan(msgSeq, infoSeq);
        checkStatus(status, "NetworkPartitionsData::ChatMessageDataReader::return_loan");

        /* Sleep for some amount of time, so as not to consume too many CPU cycles. */
        sleep(1);
    }

    /* Remove the DataReader */
    status = chatSubscriber->delete_datareader(chatAdmin.in());
    checkStatus(status, "DDS::Subscriber::delete_datareader");

    /* Remove the Subscriber. */
    status = participant->delete_subscriber(chatSubscriber.in());
    checkStatus(status, "DDS::DomainParticipant::delete_subscriber");

    /* Remove the Topic. */
    status = participant->delete_topic(chatMessageTopic.in());
    checkStatus(status, "DDS::DomainParticipant::delete_topic (chatMessageTopic)");

    /* De-allocate the type-names. */
    string_free(chatMessageTypeName);

    /* Remove the DomainParticipant. */
    status = dpf->delete_participant(participant.in());
    checkStatus(status, "DDS::DomainParticipantFactory::delete_participant");

    return 0;
}
Exemple #2
0
int
main (
    int ,
    char *[])
{
    /* Generic DDS entities */
    DomainParticipant_var           participant;
    Topic_var                       chatMessageTopic;
    Topic_var                       nameServiceTopic;
    Subscriber_var                  chatSubscriber;
    DataReader_ptr                  parentReader;
    QueryCondition_var              singleUser;
    ReadCondition_var               newUser;
    StatusCondition_var             leftUser;
    WaitSet_var                     userLoadWS;
    LivelinessChangedStatus         livChangStatus;

    /* QosPolicy holders */
    TopicQos                        setting_topic_qos;
    TopicQos                        reliable_topic_qos;
    SubscriberQos                   sub_qos;
    DataReaderQos                   message_qos;

    /* DDS Identifiers */
    DomainId_t                      domain = NULL;
    ReturnCode_t                    status;
    ConditionSeq                    guardList;

    /* Type-specific DDS entities */
    ChatMessageTypeSupport_var      chatMessageTS;
    NameServiceTypeSupport_var      nameServiceTS;
    NameServiceDataReader_var       nameServer;
    ChatMessageDataReader_var       loadAdmin;
    ChatMessageSeq                  msgList;
    NameServiceSeq                  nsList;
    SampleInfoSeq                   infoSeq;
    SampleInfoSeq                   infoSeq2;

    /* Others */
    StringSeq                       args;
    char *                          chatMessageTypeName = NULL;
    char *                          nameServiceTypeName = NULL;

    bool                            closed = false;
    CORBA::Long                     prevCount = 0;
    DWORD                           tid;
    HANDLE                          tHandle = INVALID_HANDLE_VALUE;

    /* Create a DomainParticipant (using the 'TheParticipantFactory' convenience macro). */
    participant = TheParticipantFactory->create_participant (
        domain,
        PARTICIPANT_QOS_DEFAULT,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(participant.in(), "DDS::DomainParticipantFactory::create_participant");

    /* Register the required datatype for ChatMessage. */
    chatMessageTS = new ChatMessageTypeSupport();
    checkHandle(chatMessageTS.in(), "new ChatMessageTypeSupport");
    chatMessageTypeName = chatMessageTS->get_type_name();
    status = chatMessageTS->register_type(participant.in(), chatMessageTypeName);
    checkStatus(status, "Chat::ChatMessageTypeSupport::register_type");

    /* Register the required datatype for NameService. */
    nameServiceTS = new NameServiceTypeSupport();
    checkHandle(nameServiceTS.in(), "new NameServiceTypeSupport");
    nameServiceTypeName =  nameServiceTS->get_type_name();
    status = nameServiceTS->register_type(participant.in(), nameServiceTypeName);
    checkStatus(status, "Chat::NameServiceTypeSupport::register_type");

    /* Set the ReliabilityQosPolicy to RELIABLE. */
    status = participant->get_default_topic_qos(reliable_topic_qos);
    checkStatus(status, "DDS::DomainParticipant::get_default_topic_qos");
    reliable_topic_qos.reliability.kind = RELIABLE_RELIABILITY_QOS;

    /* Make the tailored QoS the new default. */
    status = participant->set_default_topic_qos(reliable_topic_qos);
    checkStatus(status, "DDS::DomainParticipant::set_default_topic_qos");

    /* Use the changed policy when defining the ChatMessage topic */
    chatMessageTopic = participant->create_topic(
        "Chat_ChatMessage",
        chatMessageTypeName,
        reliable_topic_qos,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(chatMessageTopic.in(), "DDS::DomainParticipant::create_topic (ChatMessage)");

    /* Set the DurabilityQosPolicy to TRANSIENT. */
    status = participant->get_default_topic_qos(setting_topic_qos);
    checkStatus(status, "DDS::DomainParticipant::get_default_topic_qos");
    setting_topic_qos.durability.kind = TRANSIENT_DURABILITY_QOS;

    /* Create the NameService Topic. */
    nameServiceTopic = participant->create_topic(
        "Chat_NameService",
        nameServiceTypeName,
        setting_topic_qos,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(nameServiceTopic.in(), "DDS::DomainParticipant::create_topic");

    /* Adapt the default SubscriberQos to read from the "ChatRoom" Partition. */
    status = participant->get_default_subscriber_qos (sub_qos);
    checkStatus(status, "DDS::DomainParticipant::get_default_subscriber_qos");
    sub_qos.partition.name.length(1);
    sub_qos.partition.name[0UL] = "ChatRoom";

    /* Create a Subscriber for the UserLoad application. */
    chatSubscriber = participant->create_subscriber(sub_qos, NULL, STATUS_MASK_NONE);
    checkHandle(chatSubscriber.in(), "DDS::DomainParticipant::create_subscriber");

    /* Create a DataReader for the NameService Topic (using the appropriate QoS). */
    parentReader = chatSubscriber->create_datareader(
        nameServiceTopic.in(),
        DATAREADER_QOS_USE_TOPIC_QOS,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(parentReader, "DDS::Subscriber::create_datareader (NameService)");

    /* Narrow the abstract parent into its typed representative. */
    nameServer = NameServiceDataReader::_narrow(parentReader);
    checkHandle(nameServer.in(), "Chat::NameServiceDataReader::_narrow");

    /* Adapt the DataReaderQos for the ChatMessageDataReader to keep track of all messages. */
    status = chatSubscriber->get_default_datareader_qos(message_qos);
    checkStatus(status, "DDS::Subscriber::get_default_datareader_qos");
    status = chatSubscriber->copy_from_topic_qos(message_qos, reliable_topic_qos);
    checkStatus(status, "DDS::Subscriber::copy_from_topic_qos");
    message_qos.history.kind = KEEP_ALL_HISTORY_QOS;

    /* Create a DataReader for the ChatMessage Topic (using the appropriate QoS). */
    parentReader = chatSubscriber->create_datareader(
        chatMessageTopic.in(),
        message_qos,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(parentReader, "DDS::Subscriber::create_datareader (ChatMessage)");

    /* Narrow the abstract parent into its typed representative. */
    loadAdmin = ChatMessageDataReader::_narrow(parentReader);
    checkHandle(loadAdmin.in(), "Chat::ChatMessageDataReader::_narrow");

    /* Initialize the Query Arguments. */
    args.length(1);
    args[0UL] = "0";

    /* Create a QueryCondition that will contain all messages with userID=ownID */
    singleUser = loadAdmin->create_querycondition(
        ANY_SAMPLE_STATE,
        ANY_VIEW_STATE,
        ANY_INSTANCE_STATE,
        "userID=%0",
        args);
    checkHandle(singleUser.in(), "DDS::DataReader::create_querycondition");

    /* Create a ReadCondition that will contain new users only */
    newUser = nameServer->create_readcondition(
        NOT_READ_SAMPLE_STATE,
        NEW_VIEW_STATE,
        ALIVE_INSTANCE_STATE);
    checkHandle(newUser.in(), "DDS::DataReader::create_readcondition");

    /* Obtain a StatusCondition that triggers only when a Writer changes Liveliness */
    leftUser = loadAdmin->get_statuscondition();
    checkHandle(leftUser.in(), "DDS::DataReader::get_statuscondition");
    status = leftUser->set_enabled_statuses(LIVELINESS_CHANGED_STATUS);
    checkStatus(status, "DDS::StatusCondition::set_enabled_statuses");

    /* Create a bare guard which will be used to close the room */
    escape = new GuardCondition();

    /* Create a waitset and add the ReadConditions */
    userLoadWS = new WaitSet();
    status = userLoadWS->attach_condition(newUser.in());
    checkStatus(status, "DDS::WaitSet::attach_condition (newUser)");
    status = userLoadWS->attach_condition(leftUser.in());
    checkStatus(status, "DDS::WaitSet::attach_condition (leftUser)");
    status = userLoadWS->attach_condition(escape.in());
    checkStatus(status, "DDS::WaitSet::attach_condition (escape)");

    /* Initialize and pre-allocate the GuardList used to obtain the triggered Conditions. */
    guardList.length(3);

    /* Remove all known Users that are not currently active. */
    status = nameServer->take(
        nsList,
        infoSeq,
        LENGTH_UNLIMITED,
        ANY_SAMPLE_STATE,
        ANY_VIEW_STATE,
        NOT_ALIVE_INSTANCE_STATE);
    checkStatus(status, "Chat::NameServiceDataReader::take");
    status = nameServer->return_loan(nsList, infoSeq);
    checkStatus(status, "Chat::NameServiceDataReader::return_loan");

    /* Start the sleeper thread. */
    tHandle = CreateThread(NULL, 0, delayedEscape, NULL, 0, &tid);

    while (!closed) {
        /* Wait until at least one of the Conditions in the waitset triggers. */
        status = userLoadWS->wait(guardList, DURATION_INFINITE);
        checkStatus(status, "DDS::WaitSet::wait");

        /* Walk over all guards to display information */
        for (CORBA::ULong i = 0; i < guardList.length(); i++) {
            if ( guardList[i].in() == newUser.in() ) {
                /* The newUser ReadCondition contains data */
                status = nameServer->read_w_condition(
                    nsList,
                    infoSeq,
                    LENGTH_UNLIMITED,
                    newUser.in() );
                checkStatus(status, "Chat::NameServiceDataReader::read_w_condition");

                for (CORBA::ULong j = 0; j < nsList.length(); j++) {
                    cout << "New user: "******"Chat::NameServiceDataReader::return_loan");

            } else if ( guardList[i].in() == leftUser.in() ) {
                /* Some liveliness has changed (either a DataWriter joined or a DataWriter left) */
                status = loadAdmin->get_liveliness_changed_status(livChangStatus);
                checkStatus(status, "DDS::DataReader::get_liveliness_changed_status");
                if (livChangStatus.alive_count < prevCount) {
                    /* A user has left the ChatRoom, since a DataWriter lost its liveliness */
                    /* Take the effected users so tey will not appear in the list later on. */
                    status = nameServer->take(
                        nsList,
                        infoSeq,
                        LENGTH_UNLIMITED,
                        ANY_SAMPLE_STATE,
                        ANY_VIEW_STATE,
                        NOT_ALIVE_NO_WRITERS_INSTANCE_STATE);
                    checkStatus(status, "Chat::NameServiceDataReader::take");

                    for (CORBA::ULong j = 0; j < nsList.length(); j++) {
                        /* re-apply query arguments */
                        ostringstream numberString;
                        numberString << nsList[j].userID;
                        args[0UL] = numberString.str().c_str();
                        status = singleUser->set_query_parameters(args);
                        checkStatus(status, "DDS::QueryCondition::set_query_parameters");

                        /* Read this users history */
                        status = loadAdmin->take_w_condition(
                            msgList,
                            infoSeq2,
                            LENGTH_UNLIMITED,
                            singleUser.in() );
                        checkStatus(status, "Chat::ChatMessageDataReader::take_w_condition");

                        /* Display the user and his history */
                        cout << "Departed user " << nsList[j].name << " has sent " <<
                            msgList.length() << " messages." << endl;
                        status = loadAdmin->return_loan(msgList, infoSeq2);
                        checkStatus(status, "Chat::ChatMessageDataReader::return_loan");
                    }
                    status = nameServer->return_loan(nsList, infoSeq);
                    checkStatus(status, "Chat::NameServiceDataReader::return_loan");
                }
                prevCount = livChangStatus.alive_count;

            } else if ( guardList[i].in() == escape.in() ) {
                cout << "UserLoad has terminated." << endl;
                closed = true;
            }
            else
            {
                assert(0);
            };
        } /* for */
    } /* while (!closed) */

    /* Remove all Conditions from the WaitSet. */
    status = userLoadWS->detach_condition( escape.in() );
    checkStatus(status, "DDS::WaitSet::detach_condition (escape)");
    status = userLoadWS->detach_condition( leftUser.in() );
    checkStatus(status, "DDS::WaitSet::detach_condition (leftUser)");
    status = userLoadWS->detach_condition( newUser.in() );
    checkStatus(status, "DDS::WaitSet::detach_condition (newUser)");

    /* Remove the type-names. */
    CORBA::string_free(chatMessageTypeName);
    CORBA::string_free(nameServiceTypeName);

    /* Free all resources */
    status = participant->delete_contained_entities();
    checkStatus(status, "DDS::DomainParticipant::delete_contained_entities");
    status = TheParticipantFactory->delete_participant( participant.in() );
    checkStatus(status, "DDS::DomainParticipantFactory::delete_participant");

    CloseHandle(tHandle);

    return 0;
}
Exemple #3
0
int
OSPL_MAIN (
    int argc,
    char *argv[])
{
    /* Generic DDS entities */
    DomainParticipantFactory_var    dpf;
    DomainParticipant_var           participant;
    Topic_var                       chatMessageTopic;
    Publisher_var                   chatPublisher;
    DataWriter_ptr                  parentWriter;

    /* QosPolicy holders */
    TopicQos                        reliable_topic_qos;
    PublisherQos                    pub_qos;
    DataWriterQos                   dw_qos;

    /* DDS Identifiers */
    DomainId_t                      domain = 0;
    InstanceHandle_t                userHandle;
    ReturnCode_t                    status;

    /* Type-specific DDS entities */
    ChatMessageTypeSupport_var      chatMessageTS;
    ChatMessageDataWriter_var       talker;

    /* Sample definitions */
    ChatMessage                     *msg;   /* Example on Heap */

    /* Others */
    int                             ownID = 1;
    int                             i;
    const char                      *partitionName = "ChatRoom1";
    char                            *chatMessageTypeName = NULL;
    char                            buf[MAX_MSG_LEN];

#ifdef INTEGRITY
#ifdef CHATTER_QUIT
    ownID = -1;
#else
    ownID = 1;
#endif
#else
    /* Options: Chatter [ownID] */
    if (argc > 1) {
        ownID = atoi(argv[1]);
    }
#endif

    /* Create a DomainParticipantFactory and a DomainParticipant (using Default QoS settings. */
    dpf = DomainParticipantFactory::get_instance ();
    checkHandle(dpf.in(), "DDS::DomainParticipantFactory::get_instance");
    participant = dpf->create_participant(domain, PARTICIPANT_QOS_DEFAULT, NULL, STATUS_MASK_NONE);
    checkHandle(participant.in(), "DDS::DomainParticipantFactory::create_participant");

    /* Register the required datatype for ChatMessage. */
    chatMessageTS = new ChatMessageTypeSupport();
    checkHandle(chatMessageTS.in(), "new ChatMessageTypeSupport");
    chatMessageTypeName = chatMessageTS->get_type_name();
    status = chatMessageTS->register_type(
        participant.in(),
        chatMessageTypeName);
    checkStatus(status, "NetworkPartitionsData::ChatMessageTypeSupport::register_type");

    /* Set the ReliabilityQosPolicy to RELIABLE. */
    status = participant->get_default_topic_qos(reliable_topic_qos);
    checkStatus(status, "DDS::DomainParticipant::get_default_topic_qos");
    reliable_topic_qos.reliability.kind = RELIABLE_RELIABILITY_QOS;

    /* Make the tailored QoS the new default. */
    status = participant->set_default_topic_qos(reliable_topic_qos);
    checkStatus(status, "DDS::DomainParticipant::set_default_topic_qos");

    /* Use the changed policy when defining the ChatMessage topic */
    chatMessageTopic = participant->create_topic(
        "Chat_ChatMessage",
        chatMessageTypeName,
        reliable_topic_qos,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(chatMessageTopic.in(), "DDS::DomainParticipant::create_topic (ChatMessage)");

    /* Adapt the default PublisherQos to write into the "ChatRoom1" Partition. */
    status = participant->get_default_publisher_qos (pub_qos);
    checkStatus(status, "DDS::DomainParticipant::get_default_publisher_qos");
    pub_qos.partition.name.length(1);
    pub_qos.partition.name[0] = partitionName;

    /* Create a Publisher for the chatter application. */
    chatPublisher = participant->create_publisher(pub_qos, NULL, STATUS_MASK_NONE);
    checkHandle(chatPublisher.in(), "DDS::DomainParticipant::create_publisher");

    /* Create a DataWriter for the ChatMessage Topic (using the appropriate QoS). */
    parentWriter = chatPublisher->create_datawriter(
        chatMessageTopic.in(),
        DATAWRITER_QOS_USE_TOPIC_QOS,
        NULL,
        STATUS_MASK_NONE);
    checkHandle(parentWriter, "DDS::Publisher::create_datawriter (chatMessage)");

    /* Narrow the abstract parent into its typed representative. */
    talker = ChatMessageDataWriter::_narrow(parentWriter);
    checkHandle(talker.in(), "NetworkPartitionsData::ChatMessageDataWriter::_narrow");

    /* Initialize the chat messages on Heap. */
    msg = new ChatMessage();
    checkHandle(msg, "new ChatMessage");
    msg->userID = ownID;
    msg->index = 0;
    if (ownID == TERMINATION_MESSAGE) {
        snprintf(buf, MAX_MSG_LEN, "Termination message.");
    } else {
        snprintf(buf, MAX_MSG_LEN, "Hi there, I will send you %d more messages.", NUM_MSG);
    }
    msg->content = string_dup(buf);
    cout << "Writing message: \"" << msg->content  << "\"" << endl;

    /* Register a chat message for this user (pre-allocating resources for it!!) */
    userHandle = talker->register_instance(*msg);

    /* Write a message using the pre-generated instance handle. */
    status = talker->write(*msg, userHandle);
    checkStatus(status, "NetworkPartitionsData::ChatMessageDataWriter::write");

    sleep (1); /* do not run so fast! */

    /* Write any number of messages, re-using the existing string-buffer: no leak!!. */
    for (i = 1; i <= NUM_MSG && ownID != TERMINATION_MESSAGE; i++) {
        msg->index = i;
        snprintf(buf, MAX_MSG_LEN, "Message no. %d", i);
        msg->content = string_dup(buf);
        cout << "Writing message: \"" << msg->content << "\"" << endl;
        status = talker->write(*msg, userHandle);
        checkStatus(status, "NetworkPartitionsData::ChatMessageDataWriter::write");
        sleep (1); /* do not run so fast! */
    }

    /* Leave the room by disposing and unregistering the message instance. */
    status = talker->dispose(*msg, userHandle);
    checkStatus(status, "NetworkPartitionsData::ChatMessageDataWriter::dispose");
    status = talker->unregister_instance(*msg, userHandle);
    checkStatus(status, "NetworkPartitionsData::ChatMessageDataWriter::unregister_instance");

    /* Release the data-samples. */
    delete msg;     // msg allocated on heap: explicit de-allocation required!!

    /* Remove the DataWriters */
    status = chatPublisher->delete_datawriter( talker.in() );
    checkStatus(status, "DDS::Publisher::delete_datawriter (talker)");

    /* Remove the Publisher. */
    status = participant->delete_publisher( chatPublisher.in() );
    checkStatus(status, "DDS::DomainParticipant::delete_publisher");

    status = participant->delete_topic( chatMessageTopic.in() );
    checkStatus(status, "DDS::DomainParticipant::delete_topic (chatMessageTopic)");

    /* Remove the type-names. */
    string_free(chatMessageTypeName);

    /* Remove the DomainParticipant. */
    status = dpf->delete_participant( participant.in() );
    checkStatus(status, "DDS::DomainParticipantFactory::delete_participant");

    cout << "Completed Chatter example" << endl;
    return 0;
}