Hi On Tue, Oct 30, 2018 at 5:37 AM Eduardo Habkost <ehabk...@redhat.com> wrote: > > On Mon, Oct 29, 2018 at 10:56:57AM +0100, Igor Mammedov wrote: > > On Fri, 26 Oct 2018 12:13:21 -0300 > > Eduardo Habkost <ehabk...@redhat.com> wrote: > > > > > On Mon, Oct 22, 2018 at 03:33:30PM +0100, Igor Mammedov wrote: > > > > On Wed, 12 Sep 2018 16:55:23 +0400 > > > > Marc-André Lureau <marcandre.lur...@redhat.com> wrote: > > > > > > > > > Improve a bit code readability. > > > > > > > > > > Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com> > > > > > --- > > > > > include/qom/object_interfaces.h | 4 ++++ > > > > > qom/object.c | 4 ++-- > > > > > qom/object_interfaces.c | 9 +++------ > > > > > 3 files changed, 9 insertions(+), 8 deletions(-) > > > > > > > > > > diff --git a/include/qom/object_interfaces.h > > > > > b/include/qom/object_interfaces.h > > > > > index 4d513fb329..46b0861457 100644 > > > > > --- a/include/qom/object_interfaces.h > > > > > +++ b/include/qom/object_interfaces.h > > > > > @@ -9,9 +9,13 @@ > > > > > #define USER_CREATABLE_CLASS(klass) \ > > > > > OBJECT_CLASS_CHECK(UserCreatableClass, (klass), \ > > > > > TYPE_USER_CREATABLE) > > > > > +#define IS_USER_CREATABLE_CLASS(klass) \ > > > > > + object_class_dynamic_cast(OBJECT_CLASS(oc), TYPE_USER_CREATABLE) > > > > > #define USER_CREATABLE_GET_CLASS(obj) \ > > > > > OBJECT_GET_CLASS(UserCreatableClass, (obj), \ > > > > > TYPE_USER_CREATABLE) > > > > > +#define IS_USER_CREATABLE(obj) \ > > > > > + object_dynamic_cast(OBJECT(obj), TYPE_USER_CREATABLE) > > > > > #define USER_CREATABLE(obj) \ > > > > > INTERFACE_CHECK(UserCreatable, (obj), \ > > > > > TYPE_USER_CREATABLE) > > > > > diff --git a/qom/object.c b/qom/object.c > > > > > index 75d1d48944..0703e8e4ff 100644 > > > > > --- a/qom/object.c > > > > > +++ b/qom/object.c > > > > > @@ -424,7 +424,7 @@ void object_initialize_childv(Object *parentobj, > > > > > const char *propname, > > > > > goto out; > > > > > } > > > > > > > > > > - if (object_dynamic_cast(obj, TYPE_USER_CREATABLE)) { > > > > > + if (IS_USER_CREATABLE(obj)) { > > > > > user_creatable_complete(obj, &local_err); > > > > > if (local_err) { > > > > > object_unparent(obj); > > > > > @@ -605,7 +605,7 @@ Object *object_new_with_propv(const char > > > > > *typename, > > > > > goto error; > > > > > } > > > > > > > > > > - if (object_dynamic_cast(obj, TYPE_USER_CREATABLE)) { > > > > > + if (IS_USER_CREATABLE(obj)) { > > > > > user_creatable_complete(obj, &local_err); > > > > > if (local_err) { > > > > > object_unparent(obj); > > > > > diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c > > > > > index 72b97a8bed..e3084bc04a 100644 > > > > > --- a/qom/object_interfaces.c > > > > > +++ b/qom/object_interfaces.c > > > > > @@ -10,18 +10,15 @@ > > > > > > > > > > void user_creatable_complete(Object *obj, Error **errp) > > > > > { > > > > > - > > > > > UserCreatableClass *ucc; > > > > > - UserCreatable *uc = > > > > > - (UserCreatable *)object_dynamic_cast(obj, > > > > > TYPE_USER_CREATABLE); > > > > > > > > > > - if (!uc) { > > > > > + if (!IS_USER_CREATABLE(obj)) { > > > > > return; > > > > > } > > > > > > > > > > - ucc = USER_CREATABLE_GET_CLASS(uc); > > > > > + ucc = USER_CREATABLE_GET_CLASS(obj); > > > > > if (ucc->complete) { > > > > > - ucc->complete(uc, errp); > > > > > + ucc->complete(USER_CREATABLE(obj), errp); > > > > ^^^ > > > > even though function becomes more concise, > > > > this will call expensive dynamic cast 2nd time (IS_USER_CREATABLE was > > > > the 1st and discarded) > > > > so I'm not sure is a good idea to regress startup time for readability.
I hope it's not measurable, unless we create billions of objects. Do you want some figures? > > > > > > (INTERFACE_CHECK is a nop if CONFIG_QOM_CAST_DEBUG is not > > > enabled, so I don't understand how it would regress startup time. > > Isn't it enabled by default though? > > Maybe we should flip default to disabled then cast should be ok and enable > > it > > when generic '--debug' is enabled. > > This is called only once for each -object option. Even if QOM > debugging is enabled by default I don't see why it wouldn't be OK > to call object_dynamic_cast_assert() here. Yes, imho it's very marginal. Thus I would value more readability. Alternatively, we can consider replacing ucc->complete(USER_CREATABLE(obj), errp); by ucc->complete((UserCreatable*)obj, errp); to get back to the same number of dynamic_cast calls.