gdi32: Optionally return the type from GDI_GetObjPtr().

[Alexandre Julliard]

Huw Davies <huw at codeweavers.com> writes:

> On Fri, Jul 08, 2016 at 05:24:29PM +0800, Dmitry Timoshkov wrote:
>> Huw Davies <huw at codeweavers.com> wrote:
>> 
>> > This enables get_dc_obj() to check the type without calling GetObjectType()
>> > and thus it saves additional calls to Enter/LeaveCriticalSection().
>> > 
>> > Signed-off-by: Huw Davies <huw at codeweavers.com>
>> > ---
>> > This reduces the runtime of the dib tests by about 8% and achieves a similar
>> > increase in performance with the drawing phase of a (gdi heavy) app I'm
>> > looking at.
>> ...
>> > -    bmp = GDI_GetObjPtr( hbitmap, OBJ_BITMAP );
>> > +    bmp = GDI_GetObjPtr( hbitmap, OBJ_BITMAP, NULL );
>> 
>> Did you consider introducing GDI_GetObjPtrEx() with additional pointer to
>> type, and making a shortcut by defining/calling it by a not Ex version?
>
> No.
>
>> That would simplify the patch and avoid penalizing/changing the callers
>> that don't need the type.
>
> We don't don't need to retain backwards compatibility so I don't see
> the point, indeed an additional 'Ex' version would be more
> confusing IMO.  Almost all of the time in that function is spent
> grabbing the crit sec, so any time saved by not filling in the out
> param is totally negligible.

The performance impact is negligible, but it doesn't make a lot of sense
to return the type when it was already specified by the caller. Some
kind of get_any_obj_ptr(HGDIOBJ, WORD *) function for the any type case
would probably be cleaner.

-- 
Alexandre Julliard
julliard at winehq.org