Propagate the connection context to exported methods.

[miccoli]

If I got it right, each connection has an associated context, accessible as func (*Conn)Context, however this context is not available to exported methods.

It would be nice if the connection context could be propagate to the exported methods, something like this:

type service struct{}

func (s service) MethodWithContext(ctx context.Context) (err *dbus.Error) {
	// propagate DBus connection ctx
	// ...
	return
}

// ...

func main() {
	var s service

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	conn, err := dbus.ConnectSessionBus(dbus.WithContext(ctx))
	// ...        
	err = conn.Export(s, "/com/example/Object", "com.example.Interface")
	// ...        

}

The use case is clear: in the above MethodWithContext I have to call some long running routines that require a context argument. The context should be able to cross the API boundary so that cancellation/cleanup is possible when the connection is closed.

For now I'm forced to write

func (s service) MethodWithContext() (err *dbus.Error) {
	ctx := context.TODO()
	// ...
	return
}

which is suboptimal.