[PATCH] wayland-server: Add APIs to get some structure's value
강정현
jhyuni.kang at samsung.com
Thu Jun 23 10:47:23 UTC 2016
Dear, Mr. Pekka Paalanen.
Thanks you for your rapid reply and
I understand what you mean.
Yes, I just want to make like weston-info.
But I want to insert extra information than weston-info.
Weston-info just print interface's name/version/id about user defined
interface.
So I can't print requests and events supported by interfaces.
And weston-info had difficult to query derived interfaces.
(I'm not sure that this is right expression.)
wl_seat and wl_keyboard/wl_pointer/wl_touch is similar to derived interface.
We could know how to get wl_keyboard because this is a base interface
supported in wayland.
So weston-info wait wl_keyboard using roundtrip.
But the debug tool like weston-info did not know,
how many derived interfaces were supported in this system.
So it did not print all of interfaces.
Because of this issue, I approach server side: global_list.
You said that "it is just a database generated from the XML files"
Yes, that is absolutely right.
I want to make debug tool like weston-info but give more information.
To give comfortable way to get information about wayland server and
protocol.
Can I give to you one more question?
Take weston-info to base, can I solve those problems?
1st, get requests/events information(such as name)
2nd, get whole of derived interfaces if I do not know that interface.
If it is not, and it is better method that get these information from XML,
(like you refer to prior email)
I will try that way.
Anyway thank you for your reply and attention.
It is helpful to me, so I appreciate these reply to you.
Thanks and regards,
JengHyun Kang.
> -----Original Message-----
> From: Pekka Paalanen [mailto:ppaalanen at gmail.com]
> Sent: Wednesday, June 22, 2016 10:47 PM
> To: ______
> Cc: wayland-devel at lists.freedesktop.org
> Subject: Re: [PATCH] wayland-server: Add APIs to get some structure's
> value
>
> On Wed, 22 Jun 2016 19:45:15 +0900
> ______ <jhyuni.kang at samsung.com> wrote:
>
> > Dear, Mr. Pekka Paalanen.
> >
> > Thank you for your reply and opinion.
> > I have checked Mr. Giulio's patch:
> > https://patchwork.freedesktop.org/series/4181/
> > But unfortunately my patch was little different with Mr. Giulio's.
> >
> > His patch is to watch interfaces binded such clients.
> > So He added wl_resource_get_interface() function to refer interface
> > from resource.
> > But My patch's purpose is that print which interface is supported in
> > this server and which requests and events are supported current
> > interface.
>
> Hi,
>
> for that, you need none of what you posted.
>
> Just make a normal client, create a wl_registry, and you will see what is
> *actually supported* by the server. You cannot even get that from the
> functions you added, because you are not taking into account the interface
> versions advertised by the server.
>
> A server does not need to support the highest interface version that it
> has the descriptions for.
>
> >
> > But if he has plan to expand "GammaRay"'s function, my patch can
> > support that.
> > Because I add this APIs to support debugging.
> >
> > I explain to my purpose to this patch.
> > So please give me more opinions.
> >
> > I want to see all of interfaces and requests/events names supported
> > current server.
> >
> > Ex> command in console: $print_supported_layout
> > [1] wl_compositor
> > -- Request List --
> > 0) create_surface
> > 1) create_region
> > -- Event List --
> >
> > [2] wl_subcompositor
> > -- Request List --
> > 0) destroy
> > 1) get_subsurface
> > -- Event List --
> >
> > Each server has different configuration, so that they could have
> > different about supported interface.
>
> As I said, you get all the runtime information you need from a wl_registry
> as a normal client, and the rest you get from the protocol XML
> descriptions that are installed in the system, also extensions, not just
> Wayland core.
>
> Try 'weston-info', works on any Wayland server.
>
> > Because this could show not only wayland's basic protocol but also
> > extra protocol which is user defined.
>
> Ok, so you want information from server supported extensions for which you
> do not have the XML files for. This is getting strange.
>
> Is this for reverse-engineering?
>
> > And it provide more convenience to client developer.
>
> This I disagree. A client developer will always need the corresponding
> protocol XML description to be able to use it. You need to generate the
> programming language bindings from XML.
>
> > The client developer can watch all of interface and requests/events
> easily.
> > (Yes, I know that to watch xml file is more easier to expert.)
>
> You can also look at what wayland-scanner generates from the XML, and you
> can push that through Doxygen. Then you will have all of nice layout,
> documentation, and C API.
>
> I would very strongly suggest writing a better document generator if
> reading XML or what we generate from it is worse than reading a runtime
> string dump that cannot include documentation.
>
> > This patch is not related to make new functions, fix bugs.
> > Just to make easier to debug.
> > Watch server's global list more easier.
>
> You can watch server's global list as a normal client just fine, just
> create a wl_registry and listen.
>
> > I don't know this is enough explain why I want to added these APIs.
> >
> > Have you give me more opinions or tips about this.
> > I'm ready to listen your opinions.
> > If you feel my purpose is reasonable I'll add more specific doc to
> > each APIs.
>
> Right, so what I understood is that you want two different things: to know
> what a server supports at runtime (weston-info gives you that), and to get
> "better" list of the interfaces. I would not consider your patch to be a
> solution to either. Your approach cannot even access the documentation we
> have so carefully written. If you need an index, then please generate an
> index from the XML descriptions.
>
> I hope I didn't totally misunderstand.
>
> Do you have a real example of your proposal being used?
>
> You made a sketch with "$print_supported_layout", but to me it is just a
> database generated from the XML files, filtered with what weston-info
> reports. You do not need any changes to libwayland or compositors or
> anything to implement that. And when you use the XML files as the source,
> you can also include the actual documentation any way you want.
>
> I am leaning on rejecting this patch.
>
>
> Thanks,
> pq
>
> > > -----Original Message-----
> > > From: wayland-devel
> > > [mailto:wayland-devel-bounces at lists.freedesktop.org]
> > > On Behalf Of Pekka Paalanen
> > > Sent: Tuesday, June 21, 2016 5:02 PM
> > > To: JengHyun Kang
> > > Cc: wayland-devel at lists.freedesktop.org
> > > Subject: Re: [PATCH] wayland-server: Add APIs to get some
> > > structure's value
> > >
> > > On Tue, 21 Jun 2016 13:45:16 +0900
> > > JengHyun Kang <jhyuni.kang at samsung.com> wrote:
> > >
> > > > This patch's purpose is getting global interface information
> > > > registerred in the server.
> > > > If global is created (used wl_global_create()), information are
> > > > saved in global_list.
> > > > But almost structures used in wayland is defined statically.
> > > > So it is hard to get structure's values in server side.
> > > >
> > > > Added following APIs.
> > > > - wl_display_get_global_list()
> > > > - wl_global_get_interface()
> > > > - wl_interface_get_name()
> > > > - wl_interface_get_method_count()
> > > > - wl_interface_get_methods()
> > > > - wl_interface_get_event_count()
> > > > - wl_interface_get_events()
> > > > - wl_message_get_name()
> > > > - wl_global_list_get_global()
> > > >
> > > > You can get interface information to combine added APIs.
> > > > (Such as interface's name and events/requests name)
> > > >
> > > > 1st, you can get wl_list:global_list to use
> > wl_display_get_global_list().
> > > > 2nd, you can get length of wl_list to use wl_list_length() and
> > > > wl_global to use wl_global_list_get_global().
> > > > wl_global is saved in list, so you need index to get wl_global.
> > > > 3rd, you can get wl_interface to use wl_global_get_interface().
> > > > 4th, in wl_interface structure, there are so many information about
> > > > interface name and events/requests information.
> > > > so you can get information to use wl_interface_get_name(),
> > > > wl_interface_get_method_count(), wl_interface_get_method(),
> > > > wl_interface_get_event_count(), wl_interface_get_event().
> > >
> > > Hi,
> > >
> > > your commit message forgot to explain the one most important thing:
> > >
> > > Why?
> > >
> > > Also, please see https://patchwork.freedesktop.org/series/4181/
> > > which is already reviewed and seems to overlap with yours. Giulio
> > > has demonstrated the use case for all the API he is adding with a
> > > single
> > > screenshot:
> > > https://i.imgur.com/ihW3d88.jpg
> > >
> > > and also roughly explaining how "GammaRay" hooks up to a compositor.
> > >
> > > It would be nice if you reviewed Giulio's series, checked how it
> > > matches your needs, and then explain what you are still missing and
> why.
> > > Personally I am in favour of Giulio's series and no-one has yet
> > > disagreed with it, so I think it has good chances of getting merged
> once polished.
> > >
> > >
> > > Thanks,
> > > pq
> > >
> > > > ---
> > > > src/wayland-server.c | 63
> > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > > > src/wayland-server.h | 27 ++++++++++++++++++++++
> > > > 2 files changed, 90 insertions(+)
> > > >
> > > > diff --git a/src/wayland-server.c b/src/wayland-server.c index
> > > > 19aa2e8..ac5c2e5 100644
> > > > --- a/src/wayland-server.c
> > > > +++ b/src/wayland-server.c
> > > > @@ -997,6 +997,63 @@ wl_global_destroy(struct wl_global *global)
> > > > free(global);
> > > > }
> > > >
> > > > +WL_EXPORT const struct wl_interface *
> > > > +wl_global_get_interface(struct wl_global *global) {
> > > > + return global->interface;
> > > > +}
> > > > +
> > > > +WL_EXPORT struct wl_global *
> > > > +wl_global_list_get_global(struct wl_list *list, int idx) {
> > > > + int i = 0;
> > > > + struct wl_global *global;
> > > > +
> > > > + wl_list_for_each(global, list, link)
> > > > + {
> > > > + if (idx == i) break;
> > > > + i++;
> > > > + }
> > > > +
> > > > + return global;
> > > > +}
> > > > +
> > > > +WL_EXPORT const char *
> > > > +wl_interface_get_name(const struct wl_interface *interface) {
> > > > + return interface->name;
> > > > +}
> > > > +
> > > > +WL_EXPORT int
> > > > +wl_interface_get_method_count(const struct wl_interface *interface)
> {
> > > > + return interface->method_count;
> > > > +}
> > > > +
> > > > +WL_EXPORT const struct wl_message *
> > > > +wl_interface_get_methods(const struct wl_interface *interface) {
> > > > + return interface->methods;
> > > > +}
> > > > +
> > > > +WL_EXPORT int
> > > > +wl_interface_get_event_count(const struct wl_interface *interface)
> {
> > > > + return interface->event_count;
> > > > +}
> > > > +
> > > > +WL_EXPORT const struct wl_message * wl_interface_get_events(const
> > > > +struct wl_interface *interface) {
> > > > + return interface->events;
> > > > +}
> > > > +
> > > > +WL_EXPORT const char *
> > > > +wl_message_get_name(const struct wl_message *message) {
> > > > + return message->name;
> > > > +}
> > > > +
> > > > /** Get the current serial number
> > > > *
> > > > * \param display The display object @@ -1035,6 +1092,12 @@
> > > > wl_display_get_event_loop(struct wl_display
> > > *display)
> > > > return display->loop;
> > > > }
> > > >
> > > > +WL_EXPORT struct wl_list *
> > > > +wl_display_get_global_list(struct wl_display *display) {
> > > > + return &display->global_list;
> > > > +}
> > > > +
> > > > WL_EXPORT void
> > > > wl_display_terminate(struct wl_display *display) { diff --git
> > > > a/src/wayland-server.h b/src/wayland-server.h index
> > > > a6e7951..3494641
> > > > 100644
> > > > --- a/src/wayland-server.h
> > > > +++ b/src/wayland-server.h
> > > > @@ -92,6 +92,33 @@ wl_display_remove_global(struct wl_display
> > > > *display,
> > > >
> > > > #endif
> > > >
> > > > +struct wl_list *
> > > > +wl_display_get_global_list(struct wl_display *display);
> > > > +
> > > > +const struct wl_interface *
> > > > +wl_global_get_interface(struct wl_global *global);
> > > > +
> > > > +const char *
> > > > +wl_interface_get_name(const struct wl_interface *interface);
> > > > +
> > > > +int
> > > > +wl_interface_get_method_count(const struct wl_interface
> > > > +*interface);
> > > > +
> > > > +const struct wl_message *
> > > > +wl_interface_get_methods(const struct wl_interface *interface);
> > > > +
> > > > +int
> > > > +wl_interface_get_event_count(const struct wl_interface
> > > > +*interface);
> > > > +
> > > > +const struct wl_message *
> > > > +wl_interface_get_events(const struct wl_interface *interface);
> > > > +
> > > > +const char *
> > > > +wl_message_get_name(const struct wl_message *message);
> > > > +
> > > > +struct wl_global *
> > > > +wl_global_list_get_global(struct wl_list *list, int idx);
> > > > +
> > > > #ifdef __cplusplus
> > > > }
> > > > #endif
> >
> >
> > _______________________________________________
> > wayland-devel mailing list
> > wayland-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/wayland-devel
More information about the wayland-devel
mailing list