[Spice-devel] [PATCH spice-gtk 1/3] usb-acl-helper: Avoid deadlock when cancelled

[Jonathon Jongsma]

On Wed, 2016-03-09 at 16:03 +0100, Fabiano Fidêncio wrote:
> On Tue, Mar 8, 2016 at 11:25 PM, Jonathon Jongsma <jjongsma at redhat.com> wrote:
> > cancelled_cb() (which is triggered when the GCancellable's "cancelled"
> > signal is emitted) called spice_usb_acl_helper_close_acl(), which calls
> > spice_usb_acl_helper_cleanup(), which in turn calls
> > g_cancellable_disconnect(). Calling g_cancellable_disconnect() from
> > within a "cancelled" handler results in a dealock, as mentioned in the
> > documentation. Instead of closing the acl here, simply return the
> > CANCELLED GError here. the cleanup() call will happen when the
> > SpiceUsbAclHelper object is destroyed.
> > ---
> >  src/usb-acl-helper.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/src/usb-acl-helper.c b/src/usb-acl-helper.c
> > index 6a49627..3145b68 100644
> > --- a/src/usb-acl-helper.c
> > +++ b/src/usb-acl-helper.c
> > @@ -162,7 +162,7 @@ static void cancelled_cb(GCancellable *cancellable,
> > gpointer user_data)
> >  {
> >      SpiceUsbAclHelper *self = SPICE_USB_ACL_HELPER(user_data);
> > 
> > -    spice_usb_acl_helper_close_acl(self);
> > +    async_result_set_cancelled(self->priv->result);
> >  }
> > 
> >  static void helper_child_watch_cb(GPid pid, gint status, gpointer
> > user_data)
> > --
> > 2.4.3
> > 
> > _______________________________________________
> > Spice-devel mailing list
> > Spice-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/spice-devel
> 
> Acked-by: Fabiano Fidêncio <fidencio at redhat.com>



So it turns out that after a bit more testing, this change is not sufficient.
Will be submitting something else after a bit more analysis.