Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
On Thu, 1 Nov 2018 12:02:03 -0300
Eduardo Habkost wrote:
> On Thu, Nov 01, 2018 at 01:16:37PM +0100, Igor Mammedov wrote:
> > On Tue, 30 Oct 2018 20:07:17 -0300
> > Eduardo Habkost wrote:
> >
> > > On Tue, Oct 30, 2018 at 03:22:43PM +0100, Igor Mammedov wrote:
> > > > On Tue, 30 Oct 2018 13:26:40 +0400
> > > > Marc-André Lureau wrote:
> > > >
> > > > > Hi
> > > > >
> > > > > On Tue, Oct 30, 2018 at 5:37 AM Eduardo Habkost
> > > > > 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 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 wrote:
> [...]
> > > > > > > > > > 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?
> > > > I recall penalty was big enough for QEMU, that we added qom debug
> > > > option,
> > > > in case of -object, the cost could be multiplied by hundreds
> > >
> > > This sounds like premature optimization. Did you measure how
> > > many nanoseconds we're saving per -object option?
> > it's not optimization, it's about not making code worse and using
> > resources reasonably object_dynamic_cast() with IS_USER_CREATABLE().
>
> How exactly is the code worse?
making it slower /doesn't matter how much/ when there is better way
to do it.
Anyways the point is moot as Mark rewrote it in another way (better)
so this question won't arise.
> >
> > I'd replace object_dynamic_cast() with IS_FOO() in places where
> > we just test but do not use the result for a better readability.
> > But is we need the result later I'd keep object_dynamic_cast(),
> > it's not much worse but allows us to reuse the result of cast.
>
> Readability is orders of magnitude more important to me.
>
> This is not readable:
> (UserCreatable *)object_dynamic_cast(obj, TYPE_USER_CREATABLE)
>
> This is readable:
> USER_CREATABLE(obj)
>
> If the overhead of the extra object_dynamic_cast() call is too
> much, it's already possible to disable QOM cast debugging.
I'm typically on the side of simplifying code and readability
but in this case I have to disagree, out of context ^^^ it might
look fine but with full context
uc = (UserCreatable *)object_dynamic_cast(obj, TYPE_USER_CREATABLE)
if(uc)
call(uc)
vs
if(IS_USER_CREATABLE(obj))
// discard above hidden cast result and do it again
call(USER_CREATABLE(obj))
the former is not horrible enough to warrant doing senseless discard.
So lets agree to disagree :)
>
> > [...]
>
Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
On Thu, Nov 01, 2018 at 01:16:37PM +0100, Igor Mammedov wrote:
> On Tue, 30 Oct 2018 20:07:17 -0300
> Eduardo Habkost wrote:
>
> > On Tue, Oct 30, 2018 at 03:22:43PM +0100, Igor Mammedov wrote:
> > > On Tue, 30 Oct 2018 13:26:40 +0400
> > > Marc-André Lureau wrote:
> > >
> > > > Hi
> > > >
> > > > On Tue, Oct 30, 2018 at 5:37 AM Eduardo Habkost
> > > > 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 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 wrote:
[...]
> > > > > > > > > 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?
> > > I recall penalty was big enough for QEMU, that we added qom debug option,
> > > in case of -object, the cost could be multiplied by hundreds
> >
> > This sounds like premature optimization. Did you measure how
> > many nanoseconds we're saving per -object option?
> it's not optimization, it's about not making code worse and using
> resources reasonably object_dynamic_cast() with IS_USER_CREATABLE().
How exactly is the code worse?
>
> I'd replace object_dynamic_cast() with IS_FOO() in places where
> we just test but do not use the result for a better readability.
> But is we need the result later I'd keep object_dynamic_cast(),
> it's not much worse but allows us to reuse the result of cast.
Readability is orders of magnitude more important to me.
This is not readable:
(UserCreatable *)object_dynamic_cast(obj, TYPE_USER_CREATABLE)
This is readable:
USER_CREATABLE(obj)
If the overhead of the extra object_dynamic_cast() call is too
much, it's already possible to disable QOM cast debugging.
> [...]
--
Eduardo
Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
On Tue, 30 Oct 2018 20:07:17 -0300
Eduardo Habkost wrote:
> On Tue, Oct 30, 2018 at 03:22:43PM +0100, Igor Mammedov wrote:
> > On Tue, 30 Oct 2018 13:26:40 +0400
> > Marc-André Lureau wrote:
> >
> > > Hi
> > >
> > > On Tue, Oct 30, 2018 at 5:37 AM Eduardo Habkost
> > > 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 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 wrote:
> > > > > > >
> > > > > > > > Improve a bit code readability.
> > > > > > > >
> > > > > > > > Signed-off-by: Marc-André Lureau
> > > > > > > > ---
> > > > > > > > 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?
> > I recall penalty was big enough for QEMU, that we added qom debug option,
> > in case of -object, the cost could be multiplied by hundreds
>
> This sounds like premature optimization. Did you measure how
> many nanose
Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
On Tue, Oct 30, 2018 at 03:22:43PM +0100, Igor Mammedov wrote:
> On Tue, 30 Oct 2018 13:26:40 +0400
> Marc-André Lureau wrote:
>
> > Hi
> >
> > On Tue, Oct 30, 2018 at 5:37 AM Eduardo Habkost 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 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 wrote:
> > > > > >
> > > > > > > Improve a bit code readability.
> > > > > > >
> > > > > > > Signed-off-by: Marc-André Lureau
> > > > > > > ---
> > > > > > > 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?
> I recall penalty was big enough for QEMU, that we added qom debug option,
> in case of -object, the cost could be multiplied by hundreds
This sounds like premature optimization. Did you measure how
many nanoseconds we're saving per -object option?
> > > > > (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 o
Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
On Tue, 30 Oct 2018 13:26:40 +0400
Marc-André Lureau wrote:
> Hi
>
> On Tue, Oct 30, 2018 at 5:37 AM Eduardo Habkost 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 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 wrote:
> > > > >
> > > > > > Improve a bit code readability.
> > > > > >
> > > > > > Signed-off-by: Marc-André Lureau
> > > > > > ---
> > > > > > 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?
I recall penalty was big enough for QEMU, that we added qom debug option,
in case of -object, the cost could be multiplied by hundreds
> > > > (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.
Probably not marginal for folks who are trying to reduce every
Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
Hi
On Tue, Oct 30, 2018 at 5:37 AM Eduardo Habkost 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 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 wrote:
> > > >
> > > > > Improve a bit code readability.
> > > > >
> > > > > Signed-off-by: Marc-André Lureau
> > > > > ---
> > > > > 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.
Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
On Mon, Oct 29, 2018 at 10:56:57AM +0100, Igor Mammedov wrote:
> On Fri, 26 Oct 2018 12:13:21 -0300
> Eduardo Habkost 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 wrote:
> > >
> > > > Improve a bit code readability.
> > > >
> > > > Signed-off-by: Marc-André Lureau
> > > > ---
> > > > 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.
> >
> > (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.
--
Eduardo
Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
On Fri, 26 Oct 2018 12:13:21 -0300
Eduardo Habkost 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 wrote:
> >
> > > Improve a bit code readability.
> > >
> > > Signed-off-by: Marc-André Lureau
> > > ---
> > > 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.
>
> (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.
Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
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 wrote:
>
> > Improve a bit code readability.
> >
> > Signed-off-by: Marc-André Lureau
> > ---
> > 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.
(INTERFACE_CHECK is a nop if CONFIG_QOM_CAST_DEBUG is not
enabled, so I don't understand how it would regress startup time.
--
Eduardo
Re: [Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
On Wed, 12 Sep 2018 16:55:23 +0400
Marc-André Lureau wrote:
> Improve a bit code readability.
>
> Signed-off-by: Marc-André Lureau
> ---
> 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.
> }
> }
>
[Qemu-devel] [PATCH 1/9] qom/user-creatable: add a few helper macros
Improve a bit code readability.
Signed-off-by: Marc-André Lureau
---
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);
}
}
--
2.19.0.rc1
