From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Subject: Re: [PATCH 6/6] libxl: vncviewer: make autopass work
	properly
Date: Fri, 4 Feb 2011 11:15:36 +0000
Message-ID: <alpine.DEB.2.00.1102041110120.7277@kaball-desktop>
References: <1296584702-20138-1-git-send-email-ian.jackson@eu.citrix.com>
	<1296584702-20138-2-git-send-email-ian.jackson@eu.citrix.com>
	<1296584702-20138-3-git-send-email-ian.jackson@eu.citrix.com>
	<1296584702-20138-4-git-send-email-ian.jackson@eu.citrix.com>
	<1296584702-20138-5-git-send-email-ian.jackson@eu.citrix.com>
	<1296584702-20138-6-git-send-email-ian.jackson@eu.citrix.com>
	<1296584702-20138-7-git-send-email-ian.jackson@eu.citrix.com>
	<alpine.DEB.2.00.1102031236040.7277@kaball-desktop>
	<19786.63117.565925.259009@mariner.uk.xensource.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Return-path: <xen-devel-bounces@lists.xensource.com>
In-Reply-To: <19786.63117.565925.259009@mariner.uk.xensource.com>
List-Unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
List-Id: xen-devel@lists.xenproject.org

On Thu, 3 Feb 2011, Ian Jackson wrote:
> Stefano Stabellini writes ("Re: [Xen-devel] [PATCH 6/6] libxl: vncviewer: make autopass work properly"):
> > On Tue, 1 Feb 2011, Ian Jackson wrote:
> > > +        if ( autopass_fd < 0 ) {
> > > +            LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR,
> > > +                             "mkstemp %s failed", tmpname);
> > > +            exit(-1);
> > > +        }
> > 
> > I don't think we should call exit here, this is a library not an
> > executable. However instead of just skipping autopass we should avoid
> > exec'ing vncviewer completely and return and error.
> 
> The caller must already tolerate the function simply causing the
> process to die, because execve can fail like that.  Ie,
> libxl_exec_vncviewer is already called only after fork.  So it seemed
> best to have the function always fail the same way.
> 
> If we had a function which merely returned the vnc connection info, I
> would agree with you that it shouldn't exit.  We should do that in 4.2.

Even though it might be tolerable to have this function exits, I still
don't see any benefits as opposed to failing with an error, considering
that this function returns an integer and the long term plan would be
to return an error anyway.
It is just a matter of checking the return value in
tools/libxl/xl_cmdimpl.c:vncviewer.