On Mon, Sep 07, 2015 at 07:41:26PM +0800, Yang Hongyang wrote: > > > On 09/07/2015 07:00 PM, Daniel P. Berrange wrote: > >On Mon, Sep 07, 2015 at 06:53:49PM +0800, Yang Hongyang wrote: > >>On 09/07/2015 05:11 PM, Stefan Hajnoczi wrote: > >>[...] > >>>>Thanks very much for the suggestion, I've already implemented it and > >>>>tested, > >>>>the code looks cleaner now. > >>>> > >>>>The last issue is the QOM thing, do Markus and Andreas have more input > >>>>about that? > >>> > >>>If you would like to see examples of QOM usage, take a look at > >>>iothread.c and/or backends/hostmem.c. > >>> > >>>The key things are: > >>> > >>>1. They use include/qom/object.h to register a type based on > >>> TYPE_OBJECT and their properties are registered using > >>> object_property_add_*(). > >>> > >>>2. They implement the TYPE_USER_CREATABLE interface so the -object > >>> command-line option can be used to instantiate them. See > >>> object_interfaces.h. > >>> > >>>As a result, a lot of code becomes unnecessary and iothread.c, in > >>>particular, is quite short. > >> > >>After looking into this, I have some questions on the implement, could you > >>please help me on this because I don't know much about the object mechanism: > >> > >>The netfilter need to be initialized after the net_init_clients, because we > >>need to attach the filter to the net client. But currently, net client is > >>not > >>using QOM, and seems that it is initialized after objects been created. So > >>here > >>comes the problem: how can I initialize a certain object later, is it > >>possiable? > > > >It is currently a bit hacky - most objects are initialized very early, > >but we have a similar problem with rng-egd which must be created /after/ > >chardevs. To deal with this in vl.c main() we have two helper methods > >object_create_initial and object_create_delayed. The delayed method though > >still happens before the net clients are created. We could probably just > >move the objec_create_delayed method invokation to later on, after net > >clients are created, but if that doesn't work just add an extra helper > >object_create_very_delayed :-) > > If it's ok to move creation of "rng-egd" later, then "move the > objec_create_delayed method invokation after net clients are created" should > solve the problem.
I think it should be ok, because IIRC, the only requirement from rng-egd was that it be created /after/ -device is processed, so moving it even later shouldn't hurt it Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
