blocking dbus system

[Auzinger, Robert]

Hi!
I'm new to the list and also to the dbus-topic, therefore please apologize in advance if I ask newbie questions.
We try to establish a dbus-system where at minimum 3 applications talk to each other over dbus. Probably there are up to 10 applications talking to each other.
At the moment there is already a problem with 3 applications. We have implemented a kind of DBus-Listener-thread which waits for incoming messages and process them if one is received.
FeatStd::Int DBusListenerThread::ThreadFn()
{
    static const FeatStd::Char* c_internalMsg = "org.freedesktop.DBus";
    dbus_connection_set_wakeup_main_function(DBusFunctions::GetConnection(), DBusListenerThread::WakeupFn, this, 0);

    while (GetStatus() == FeatStd::Internal::ThreadStatus::Running) {
        DBusConnection* conn = DBusFunctions::GetConnection();
        if (conn != 0) {
            dbus_connection_read_write(conn, 0);
            DBusMessage* msg = dbus_connection_pop_message(conn);
            if (msg != 0) {
                const FeatStd::Char* interface = dbus_message_get_interface(msg);
                if (interface != 0) {
                    printf("received: (%s, %d)\n", dbus_message_get_member(msg), dbus_message_get_serial(msg));
                    m_listener.Listen(*msg);
                    Sleep(1);
                }
                else {
                    printf("ERROR: Message with empty interface from %s !!\n", dbus_message_get_sender(msg)); => error output 1
                }

                dbus_message_unref(msg);
            }
        }
    }

    return 0;
}

Frequently we get a error when we try to send a new signal. Before the system is blocked completely and no dbus-output can be seen at all.
bool DBusFunctions::InitSignal()
{
    if (GetConnection() == 0) {
        printf("No DBus connection!\n");
        return false;
    }

    DBusError err;
    int ret = 0;

    // initialize the error value
    dbus_error_init(&err);

    // register our name on the bus, and check for errors
    ret = dbus_bus_request_name(GetConnection(), m_busName, DBUS_NAME_FLAG_REPLACE_EXISTING , &err);
    if (dbus_error_is_set(&err)) {
        fprintf(stderr, "Name Error (%s)\n", err.message); => error output 2
        dbus_error_free(&err);
    }
    if (DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER != ret &&
        DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER != ret) {
        printf("DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER != ret\n");
//        return false;
    }

    // create a signal & check for errors
    m_msg = dbus_message_new_signal(c_path,
        m_interface,
        m_name); // name of the signal

    if (NULL == m_msg)
    {
        fprintf(stderr, "Message Null\n");
        return false;
    }

    // append arguments onto signal
    dbus_message_iter_init_append(m_msg, &m_messageIterator);
    return true;
}

Do you have any idea what could be the reason for such behavior?
After a block the system is running for some time but blocks again very soon.

The error-output is the following:
Error output 1: ERROR: Message with empty interface from org.freedesktop.DBus !!
Error output 2: Name Error (Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.)

Thanks,
robert



Geschaeftsfuehrer/Managing Director: Shoji Ohashi, Amane Inoue
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