Re: [Qemu-devel] ERROR:qom/object.c:907:object_unref: assertion failed (obj->ref > 0): (0 > 0)

["Daniel P. Berrangé" <berrange@redhat.com>]

On Wed, Feb 14, 2018 at 08:27:10PM -0500, Bandan Das wrote:
> 
> I get the error mentioined in the subject line when using vncviewer with
> commit 13e1d0e71e78a925848258391a6e616b6b5ae219:
> 
> Author: Daniel P. Berrange <berrange@redhat.com>
> Date:   Thu Feb 1 16:45:14 2018 +0000
> 
>     ui: convert VNC server to QIONetListener
>     
>     The VNC server already has the ability to listen on multiple sockets.
>     Converting it to use the QIONetListener APIs though, will reduce the
>     amount of code in the VNC server and improve the clarity of what is
>     left.
>     
>     Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
>     Message-id: 20180201164514.10330-1-berrange@redhat.com
>     Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> 
> 
> It appears to be related to the unconditional unref in vnc_listen_io:
> static void vnc_listen_io(QIONetListener *listener,
>                           QIOChannelSocket *cioc,
>                           void *opaque)
> {
>     VncDisplay *vd = opaque;
>     bool isWebsock = listener == vd->wslistener;
> 
>     qio_channel_set_name(QIO_CHANNEL(cioc),
>                          isWebsock ? "vnc-ws-server" : "vnc-server");
>     qio_channel_set_delay(QIO_CHANNEL(cioc), false);
>     vnc_connect(vd, cioc, false, isWebsock);
>     object_unref(OBJECT(cioc));
> }

[snip]

> So, it looks like the unref is already being handled as part of the event
> handling stuff when the window is closed. Is this a known issue/Is the
> object_unref above required ?

Yeah, my bad. The vnc_listen_io fnuc does *not* own the reference it is
given in the cioc parameter, so should not be unref'ing it.

Regards,
Daniel
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