[libvirt] [PATCH 03/16] Add callback to virNetClient to be invoked on EOF

[Daniel P. Berrange]

On Thu, Jul 19, 2012 at 04:18:33PM +0800, Daniel Veillard wrote:
> > @@ -1636,17 +1657,21 @@ void virNetClientIncomingEvent(virNetSocketPtr sock,
> >          VIR_DEBUG("%s : VIR_EVENT_HANDLE_HANGUP or "
> >                    "VIR_EVENT_HANDLE_ERROR encountered", __FUNCTION__);
> >          virNetSocketRemoveIOCallback(sock);
> > -        goto done;
> > +        goto eof;
> >      }
> >  
> >      if (events & VIR_EVENT_HANDLE_WRITABLE) {
> > -        if (virNetClientIOHandleOutput(client) < 0)
> > +        if (virNetClientIOHandleOutput(client) < 0) {
> >              virNetSocketRemoveIOCallback(sock);
> > +            goto eof;
> > +        }
> >      }
> >  
> >      if (events & VIR_EVENT_HANDLE_READABLE) {
> > -        if (virNetClientIOHandleInput(client) < 0)
> > +        if (virNetClientIOHandleInput(client) < 0) {
> >              virNetSocketRemoveIOCallback(sock);
> > +            goto eof;
> > +        }
> >      }
> 
> 
>   What about the case ?
>     if (client->haveTheBuck || client->wantClose) ?
> sure it's induced locally instead of getting raised by an eof

If either of those conditions are true, the virNetClientIncomingEvent
method should not be invoked - we just have a check for those at the
top as a sanity check. In the haveTheBuck==true case, this callback
will be activated again once the buck is released, so we'll deal with
EOF callbacks correctly.  In the wantClose==true case, we might miss
out invoking the EOF callback - I suspect this is only a problem if
the app code explicitly asked for a close itself, or if the keepalive
code triggers.

I'll check into this and if there are any fixes required, I'll do them
as a followup patch.

Daniel
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