From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50450) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dzPGF-00065N-LJ for qemu-devel@nongnu.org; Tue, 03 Oct 2017 11:37:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dzPGA-0005q0-Ka for qemu-devel@nongnu.org; Tue, 03 Oct 2017 11:37:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45634) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dzPGA-0005ou-Ac for qemu-devel@nongnu.org; Tue, 03 Oct 2017 11:37:26 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EC94C5F298F for ; Tue, 3 Oct 2017 15:37:24 +0000 (UTC) Date: Tue, 3 Oct 2017 12:37:22 -0300 From: Eduardo Habkost Message-ID: <20171003153722.GM17385@localhost.localdomain> References: <20171002192404.GC17385@localhost.localdomain> <1507032886-199950-1-git-send-email-imammedo@redhat.com> <20171003142501.GI17385@localhost.localdomain> <20171003170139.36e23ab7@nial.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171003170139.36e23ab7@nial.brq.redhat.com> Subject: Re: [Qemu-devel] [PATCH] qom: add helpers REGISTER_STATIC_TYPE[S]() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: qemu-devel@nongnu.org On Tue, Oct 03, 2017 at 05:01:39PM +0200, Igor Mammedov wrote: > On Tue, 3 Oct 2017 11:25:01 -0300 > Eduardo Habkost wrote: > > > On Tue, Oct 03, 2017 at 02:14:46PM +0200, Igor Mammedov wrote: > > > it will help to remove code duplication in places > > > that currently open code registration of static > > > type[s] and remove necessity to declare function > > > for type_init() to call, when only static types > > > need to be registered. > > > > > > Signed-off-by: Igor Mammedov > > > --- > > > I'm going to use it for CPU types in followup patches > > > > > > CC: ehabkost@redhat.com > > > --- > > > include/qemu/module.h | 10 ++++++++++ > > > include/qom/object.h | 10 ++++++++++ > > > qom/object.c | 9 +++++++++ > > > 3 files changed, 29 insertions(+) > > > > > > diff --git a/include/qemu/module.h b/include/qemu/module.h > > > index 56dd218..60dd632 100644 > > > --- a/include/qemu/module.h > > > +++ b/include/qemu/module.h > > > @@ -52,6 +52,16 @@ typedef enum { > > > #define type_init(function) module_init(function, MODULE_INIT_QOM) > > > #define trace_init(function) module_init(function, MODULE_INIT_TRACE) > > > > > > +#define REGISTER_STATIC_TYPES(t, nr) \ > > > > I'm unsure about the name. We already have a declarative way to > > register machine types (DEFINE_MACHINE), maybe use "DEFINE_*" for > > consistency? > > > > Also, this function won't work if t isn't a static variable, will > > it? The "STATIC" part looks redundant. > > > > In other words, how about "DEFINE_TYPE" and "DEFINE_TYPES"? > 'define' word remind me more of declaration but here we actually > register types that's why 'register' looks better to me as it says > exactly what's going here. Making it look like a declaration and not an action like "register" is on purpose, as it's not a function call anymore: it's a declaration that will make the type get registered automatically. > > > > > > > > +static void do_qemu_init_ ## t(void) \ > > > +{ \ > > > + type_register_static_array(t, nr); \ > > > > qemu/module.h doesn't include qom/object.h. I think this should > > go to either qom/object.h or a new header file. > I could move it to qom/object.h > > > > > > +} \ > > > +type_init(do_qemu_init_ ## t) > > > + > > > +#define REGISTER_STATIC_TYPE(t) \ > > > + REGISTER_STATIC_TYPES(t, 1) > > > + > > > #define block_module_load_one(lib) module_load_one("block-", lib) > > > > > > void register_module_init(void (*fn)(void), module_init_type type); > > > diff --git a/include/qom/object.h b/include/qom/object.h > > > index f3e5cff..17fcadd 100644 > > > --- a/include/qom/object.h > > > +++ b/include/qom/object.h > > > @@ -789,6 +789,16 @@ Type type_register_static(const TypeInfo *info); > > > Type type_register(const TypeInfo *info); > > > > > > /** > > > + * type_register_static_array: > > > + * @infos: The array of the new type #TypeInfo structures. > > > + * @nr_infos: number of entries in @infos > > > + * > > > + * @infos and all of the strings it points to should exist for the life time > > > + * that the type is registered. > > > + */ > > > +void type_register_static_array(const TypeInfo *infos, int nr_infos); > > > > This new function is probably less controversial than the new > > module.h-based code. Maybe worth moving to a separate patch so > > it can be merged earlier? > > > > (If I were you, I would just use type_register_static_array() > > inside the existing *_cpu_register_types() functions by now, so > > this won't block the whole series, and worry about > > REGISTER_STATIC_TYPE*/DEFINE_TYPE* later.) > it would be nice to have both in one series so that > we won't have to touch/rewrite more than once code where > static cpu types are registered. > > If you prefer I can do what you suggest and keep > *_cpu_register_types() functions > but I can't promise to return back to cleaning them up > or to REGISTER_STATIC_TYPE*/DEFINE_TYPE, so probably > someone else will have to pickup that work. No problem to me, if this is left for later. The macro saves only 3 lines of code. I think REGISTER_STATIC_TYPE*/DEFINE_TYPE* is a good idea, but considering that QOM types are not the only kind of entity we register at module_init(), we need to pick a style that can be consistently used by other subsystems (e.g. for QemuOpts, BlockDrivers, and TraceEvents). This means this could take a little longer to be discussed, and I guess you wouldn't like the discussion to block the cleanups in this series. > > > > + > > > +/** > > > * object_class_dynamic_cast_assert: > > > * @klass: The #ObjectClass to attempt to cast. > > > * @typename: The QOM typename of the class to cast to. > > > diff --git a/qom/object.c b/qom/object.c > > > index 3e18537..40b1729 100644 > > > --- a/qom/object.c > > > +++ b/qom/object.c > > > @@ -151,6 +151,15 @@ TypeImpl *type_register_static(const TypeInfo *info) > > > return type_register(info); > > > } > > > > > > +void type_register_static_array(const TypeInfo *infos, int nr_infos) > > > +{ > > > + int i; > > > + > > > + for (i = 0; i < nr_infos; i++) { > > > + assert(type_register_static(&infos[i])); > > > > Why the assert()? type_register_static() is already guaranteed > > to never return NULL. > according to doc comment type_register_static might return 0 on failure > so qemu should die in that case. We have absolutely no callers of type_register*() that check its return value, and the existing implementation guarantees it will never return NULL. Instead of making type_register_static_array() more commplex, we could just update the documentation. > > > > > This will break if compiled with -DNDEBUG: assert() won't even > > evaluate the expression if NDEBUG is defined. > > > > > + } > > > +} > > > + > > > static TypeImpl *type_get_by_name(const char *name) > > > { > > > if (name == NULL) { > > > -- > > > 2.7.4 > > > > > > -- Eduardo