Troubles with multi subscription to d-bus data

[v-sadovsky]

Hello.

I'm trying to subscribe to a d-bus event and a d-bus property.
When I implement only one type of subscription all woks fine - I receive corresponding data via d-bus (a signal or a property data).

But when I try to use both (subscribe to a signal and to a property) I have the following troubles:
When the d-bus signal comes to the corresponding channel the same data also appears on the channel that is linked to the d-bus property. And vice versa.

This is my implementation of multi subscription:
`func TestSubs() {
// connect to the DBus
bus, err := dbus.SystemBus()
if err != nil {
log.Fatalf("error: dbus not connected. %s", err)
}

defer func() {
	bus.Close()
}()

// subscribe to property
prop_ch := make(chan *dbus.Signal)
err = bus.AddMatchSignal(dbus.WithMatchObjectPath(dbusPath), dbus.WithMatchInterface(propIface), dbus.WithMatchMember(propMember))
if err != nil {
	log.Fatalf("error: failed to subscribe to dbus property. %s", err)
}
bus.Signal(prop_ch)

// subscribe to event
event_ch := make(chan *dbus.Signal)
err = bus.AddMatchSignal(dbus.WithMatchObjectPath(dbusPath), dbus.WithMatchInterface(sigIface), dbus.WithMatchMember(sigMember))
if err != nil {
	log.Fatalf("error: failed to subscribe to dbus event. %s", err)
}
bus.Signal(event_ch)

// poll received via d-bus data
for {
	select {
	case <-prop_ch:
		fmt.Println("Property has been received via d-bus")

	case <-event_ch:
		fmt.Println("Signal has been received via d-bus")

	default:
		time.Sleep(50 * time.Millisecond)
	}
}

}`

And there is the result that I get when a signal comes to the event_ch:
Signal has been received via d-bus Property has been received via d-bus

Am I doing something wrong?

Kind regards,
Viacheslau

[jhenstridge]

That is the current expected behaviour of the library: the AddSignalMatch calls tell dbus-daemon what types of signal messages we're interested in, and the Signal calls set up channels that will receive all signals received from the bus.

We don't currently have a way to create a channel that will only receive signals matching a particular rule. I agree that it would be useful to add such a feature, but it is non-trivial to implement. In particular, WithMatchSender rules that use a well known bus name require that we track the ownership of that bus name, since matching signals will instead list the unique name as the sender (i.e. something like :1.42).

[v-sadovsky]

Thanks.
Currently, I am using the "Name" property of a received dbus.Signal to check what kind of signal is coming to a channel.