[pulseaudio-discuss] Receiving signals from server in C

[Greg Knoll]

On Fri, May 30, 2014 at 3:44 PM, Tanu Kaskinen
<tanu.kaskinen at linux.intel.com> wrote:
> (Added pulseaudio-discuss back to cc.)
>
> On Fri, 2014-05-30 at 15:24 +0200, Greg Knoll wrote:
>> Thank you for your response,
>>
>>
>> Yes, I did follow that tutorial.  I didn't state it correctly in my
>> question, but I do only use the session bus to get the server
>> address.  Then I use
>>
>>
>>     *conn = dbus_connection_open(serverAddress, &err);
>>
>> to get the DBusConnection object and use this to make calls.
>
> Ok, I suppose this is not the problem then. Back to the original
> question:
>
>> However, where/how do I listen for the signal?  I also tried setting a
>> dbus match rule:
>>    dbus_bus_add_match(system_bus, "type='signal',interface='org.PulseAudio.Core1'", &err);
>
> You don't need to add a match rule (trying to do so won't do anything
> useful, because the match rules are managed by the bus daemon, and in a
> peer-to-peer connection there's no bus daemon involved at all). Do you
> register a message filter with dbus_connection_add_filter()? If not,
> then that's the problem.
>
> By the way, please don't top-post on mailing lists, and also plain text
> messages are preferred over HTML.
>
> --
> Tanu
>
>

Sorry about the top post.

I did not register a dbus_connection_add_filter().  I have added a
DBusHandlerResult function based on the examples here:
https://kernel.googlesource.com/pub/scm/bluetooth/bluez/+/utils-3.4/hcid/dbus-error.c
and
http://lists.freedesktop.org/archives/dbus/2003-September/000468.html

The second one uses an object DBusMessageHandler, which I think is
from glib/dbus-glib.  Maybe I'm wrong there.  My function looks like
this:

DBusHandlerResult listen_to_core_Handler(DBusConnection *connection,
DBusMessage *message, void *user_data)

{

    debug_print("Message received from Pulse Core.\n");

    debug_print("Signature:%s\n", dbus_message_get_signature(message));

}

and I add a call to dbus_connection_add_filter() in my main thread using:

dbus_connection_add_filter(PA_bus, listen_to_core_Handler, NULL, NULL);


Still nothing.  I should also say that the signal name string I'm
using is "org.PulseAudio.Core1.NewModule".

Thanks for all the help so far.