[Libguestfs] [PATCH 3/3] docs: Add a section about what happens to the plugin when nbdkit shuts down.

[Richard W.M. Jones]

On Tue, Nov 14, 2017 at 12:18:16PM -0600, Eric Blake wrote:
> On 11/14/2017 11:30 AM, Richard W.M. Jones wrote:
> > This was underspecified before.
> > ---
> >  docs/nbdkit-plugin.pod | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> > 
> 
> > +=head1 SHUTDOWN
> > +
> > +When nbdkit receives certain signals it will shut down (see
> > +L<nbdkit(1)/SIGNALS>).  The server will wait for any currently running
> > +plugin callbacks to finish and also call the C<.unload> callback
> > +before unloading the plugin.
> 
> Do we also guarantee that all subsequent client requests parsed off the
> wire in between the signal and when we finally call the .unload()
> callback will NOT call into the plugin, but will be immediately answered
> to the client with NBD_ESHUTDOWN?  If not, we should.

It's a good question :-)  At the moment, no, and yes we should.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top