Bug 166813

Summary:	notification "Unable to find a Multimedia Backend" pops up a thousand times
Product:	[I don't know] kde	Reporter:	Thomas Kemmerich <micrix>
Component:	general	Assignee:	Unassigned bugs mailing-list <unassigned-bugs>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	kretz, mboquien
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Thomas Kemmerich 2008-07-17 09:56:11 UTC

Version:            (using KDE 4.0.98)
Installed from:    Compiled From Sources
OS:                Linux

I compiled KDE 4.1 RC1 from sources on gentoo. I did not compile all components. If KDE starts then a notification message saying "Unable to find a Multimedia Backend" pops up. However it does not only pop up once but repeatedly until you manage to hit the ok button. Thus, after a second or so, you have about 100 notifications on your screen. If you click the ok button on any of it then all notifications disappear.
The message seems to pop up each time KDE tries to play one of its system sounds.

I might missing phonon and all that multimedia stuff - however I think that in such a case, ONE notification would be enough :)

In KDE 4.0.5 the problem does not occur. I tried KDE 4.1 Beta 1 and there the same happens as in KDE 4.1 RC1.

Comment 1 Matthias Kretz 2008-07-17 11:21:04 UTC

This is the current (4.1 RC1) code:

    static bool has_shown = false;
    const KService::List offers = listBackends();
    if (offers.isEmpty()) {
        if (!has_shown) {
            KMessageBox::error(0, i18n("Unable to find a Multimedia Backend"));
            has_shown = true;
        }
        return 0;
    }
    // Flag the warning as not shown, since if the next time the
    // list of backends is suddenly empty again the user should be
    // told.
    has_shown = false;

In order to get what you got, you need to either get the message from a new process every time, or for some reason the has_shown = false is reached - but I can't think of any scenario that would explain what you see.

Please find out whether the dialog is from the same process every time.

Comment 2 Thomas Kemmerich 2008-07-17 13:25:14 UTC

I played around a bit and found out, that the dialogs pop up whenever I right click the desktop and select "run command" or "add widgets". However, when I kill the plasma process the dialogs still pop up repeatedly. The kwin process uses most of the processor time  but I'm not sure if it is because it has to manage all these notifications or if it triggers the notification.

The above code might result in what I see, if listBackends() sometimes is empty and sometimes not... but therefore one has to study the code in more detail.

Could you tell me a way how to find out which process the dialog belongs to?

Comment 3 Matthias Kretz 2008-07-17 14:14:49 UTC

> The above code might result in what I see, if listBackends() sometimes is
> empty and sometimes not... but therefore one has to study the code in more
> detail.


if it's non-empty once the code only gets called again if it receives a dbus 
signal to exchange its backend. Otherwise it has the backend object and won't 
ever delete it again until shutdown.

> Could you tell me a way how to find out which process the dialog belongs
> to?


run xprop, click on the dialog and look for _NET_WM_PID to tell you the 
process ID.

Comment 4 Thomas Kemmerich 2008-07-17 16:22:22 UTC

The owner of all dialogs is knotify4.

Comment 5 Matthias Kretz 2008-07-17 16:29:16 UTC

> The owner of all dialogs is knotify4.


And every time with the same PID I assume?

Comment 6 Thomas Kemmerich 2008-07-17 16:31:20 UTC

correct.

Comment 7 Médéric Boquien 2008-11-08 19:02:56 UTC

Hello,

Can you still reproduce this bug with the latest KDE version? I have need seen this bug in months.

Thanks

Comment 8 Médéric Boquien 2008-11-09 15:20:03 UTC

The reported informed me that he cannot reproduce the problem anymore therefore i close the bug. Please reopen in case the bug reappears.

Thanks.