[Spice-devel] [PATCH v2 1/4] spice-channel: Properly error out if reconnect fails

[Victor Toso]

Hi,

On Tue, Sep 18, 2018 at 03:53:19AM -0400, Frediano Ziglio wrote:
> > 
> > From: Victor Toso <me at victortoso.com>
> > 
> > The channel_connect() function could fail leading to a spice-channel
> > existing as zombie (its coroutine return soon after).
> > 
> > Check if channel_connect() fails and give a proper error signal to
> > user when that happens.
> > 
> > Related: https://bugzilla.redhat.com/show_bug.cgi?id=1625550
> > Signed-off-by: Victor Toso <victortoso at redhat.com>
> > ---
> >  src/spice-channel.c | 12 ++++++++----
> >  1 file changed, 8 insertions(+), 4 deletions(-)
> > 
> > diff --git a/src/spice-channel.c b/src/spice-channel.c
> > index 0a5437c..aa035e1 100644
> > --- a/src/spice-channel.c
> > +++ b/src/spice-channel.c
> > @@ -2675,11 +2675,15 @@ cleanup:
> >      if (c->state == SPICE_CHANNEL_STATE_RECONNECTING ||
> >          c->state == SPICE_CHANNEL_STATE_SWITCHING) {
> >          g_warn_if_fail(c->event == SPICE_CHANNEL_NONE);
> > -        channel_connect(channel, c->tls);
> > -        g_object_unref(channel);
> > -    } else
> > -        g_idle_add(spice_channel_delayed_unref, data);
> > +        if (channel_connect(channel, c->tls)) {
> > +            g_object_unref(channel);
> > +            return NULL;
> > +        }
> > +
> > +        c->event = SPICE_CHANNEL_ERROR_CONNECT;
> > +    }
> >  
> > +    g_idle_add(spice_channel_delayed_unref, data);
> >      /* Co-routine exits now - the SpiceChannel object may no longer exist,
> >         so don't do anything else now unless you like SEGVs */
> 
> Patch is good, this comment is now wrong here, channel (or
> data) is still valid.

I think the comment is still right.

It says that user should not use the SpiceChannel as the
coroutine is returning, the _may_ in "SpiceChannel object may no
longer exist" is a reference to the delayed unref of the channel,
no? Which happens above the comment now, instead of in the else
{} as it was before.

So, I think it was true before and I don't think this patch
changes it?

Note also that in case that channel_connect() succeeds, it
happens with a connect_delayed() for this coroutine to return.

> Maybe
>     g_idle_add(spice_channel_delayed_unref, channel);
> 
> is more readable (data == channel).

Yep, I agree. I'll change it a send all patches again as v3

Cheers!

> 
> >      return NULL;
> 
> Frediano
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