[Spice-devel] Try to port spicec into Android

Alon Levy alevy at redhat.com
Wed Mar 9 00:39:54 PST 2011


On Wed, Mar 09, 2011 at 11:10:03AM +0800, Shuxiang Lim wrote:
> Hi,I need help!
>   Now I've managed to divided spicec-gtk into two parts libspicec.so(based
> on libpixman.so,libglib-2.0.so...No relation to X11 at all) and spicec(based
> on libspicec.so and libgtk.so...). And the glib2.0 porting to Android is
> also completed. But I'm blocked in compiling libspicec onto Android at the
Great progress!

> begining for the continuation.c uses the functions in <ucontext.h>
> :setcontext(),getcontext()..., which are some thread-related funcs as I
> know,and, definitely unsuprisingly, Android libc doesn't have them! Is there
> a way to drop or replace the use of such funcs? Or should I manually write
> setcontext from scratch?

Having a bundled libc is a really bad idea. So I guess you'll need to rewrite
them.

>   RGRDs.
> 
> On Mon, Mar 7, 2011 at 5:14 PM, Alon Levy <alevy at redhat.com> wrote:
> 
> > On Mon, Mar 07, 2011 at 09:08:28AM +0800, Shuxiang Lim wrote:
> > > Option 1: use spice-gtk with a gtk android backend
> > > a) compiling gtk for it would be possible.
> > > b) write a partial gtk backend, good enough for spice-gtk.
> > > c) no changes to spice-gtk.
> > >    Yep,that's really a good hope,but it's another project(too huge and
> > far
> > > away for me now):
> > > Project:"GTK for Android.". So now I can use only the Android SDK to
> > finish
> > > the UI(the new native UI APIs in NDK is not reliable in versions).
> >
> > Yeah, I think you're right, I can't find anyone already working on this by
> > simple web search. Maybe spice-gtk's non ui objects are dependent only on
> > gobject / stuff that is easy to just drop in (ugly, but still more
> > maintainable
> > then basing your work on spicec, long term).
> >
> > >    And also you've referred that "spicec is already platform
> > independent",
> > > that's true to Linux and Windows,but not to Android,for such independence
> > is
> > > based on the C++ independence over the os which cannot stand through the
> > > JAVA UIed android.So there is no way to just add a subdir ./android under
> > > spice/client along with ./x11 and ./windows. It should be a combined
> > proj.
> > > of C/C++ and Java. (That's why I hate Android and yearn for Maemo/Meego.)
> >
> > Definitely easier to port to Maemo :)
> >
> > >    Regards.
> > >
> > > On Fri, Mar 4, 2011 at 7:04 PM, Alon Levy <alevy at redhat.com> wrote:
> > >
> > > > On Fri, Mar 04, 2011 at 06:21:19PM +0800, Shuxiang Lim wrote:
> > > > >  Hi, friends,
> > > > >     Thanks for your replies. It's definitely right till now I've been
> > > > > working a tougher way compared to spice-gtk.And actually I've
> > considered
> > > > to
> > > > > steer my way to the latter in fear of the troublesome and crippled
> > C++
> > > > > support in Android NDK:C is more "simple and safe" in Android than
> > C++.
> > > > > But,AFAIK,there is no gtk port for Android yet. And the biggest
> > obstacle
> > > > is
> > > > > the framework of Android:in its design,all UI should be done in JAVA
> > > > powered
> > > > > by SKIA libs.Therefore the port of UI libs(GTK,etc) will be choked by
> > the
> > > > > I/O level because Android don't completely expose them  at all!(I
> > once
> > > > > managed to port Xfbdev onto it,but that's not commercially practical
> > at
> > > > all,
> > > > > it's just a geeky trick maybe,an app in Android SHOULD NOT do this.)
> > Only
> > > > > the algorithm/data computing-related C/C++ libs are welcomed to be
> > the
> > > > JNI
> > > > > servants to JAVA UI apps in Android.
> > > > >    You see, in such aspect, there is not too much diff between the
> > C++
> > > > way
> > > > > and gtk way in the porting of UI part.
> > > >
> > > > I'm going to try to prove that wrong by grepping hoping it makes sense,
> > I
> > > > never
> > > > actually coded in gtk:
> > > >
> > > > $ git grep GObjectClass
> > > > gtk/channel-cursor.c:    GObjectClass *gobject_class =
> > > > G_OBJECT_CLASS(klass);
> > > > gtk/channel-display.c:    GObjectClass *gobject_class =
> > > > G_OBJECT_CLASS(klass);
> > > > gtk/channel-inputs.c:    GObjectClass *gobject_class =
> > > > G_OBJECT_CLASS(klass);
> > > > gtk/channel-main.c:    GObjectClass *gobject_class =
> > G_OBJECT_CLASS(klass);
> > > > gtk/channel-playback.c:    GObjectClass *gobject_class =
> > > > G_OBJECT_CLASS(klass);
> > > > gtk/channel-record.c:    GObjectClass *gobject_class =
> > > > G_OBJECT_CLASS(klass);
> > > > gtk/spice-audio.h:    GObjectClass parent_class;
> > > > gtk/spice-channel.c:    GObjectClass *gobject_class = G_OBJECT_CLASS
> > > > (klass);
> > > > gtk/spice-channel.h:    GObjectClass parent_class;
> > > > gtk/spice-gstaudio.c:    GObjectClass *gobject_class =
> > > > G_OBJECT_CLASS(klass);
> > > > gtk/spice-pulse.c:    GObjectClass *gobject_class =
> > G_OBJECT_CLASS(klass);
> > > > gtk/spice-session.c:    GObjectClass *gobject_class =
> > > > G_OBJECT_CLASS(klass);
> > > > gtk/spice-session.h:    GObjectClass parent_class;
> > > > gtk/spice-widget.c:    GObjectClass *gobject_class =
> > G_OBJECT_CLASS(klass);
> > > >
> > > > otoh:
> > > > U playa:spice-gtk alon (master)$ git grep --name-only GdkWindow
> > > > gtk/spice-widget-cairo.c
> > > > gtk/spice-widget.c
> > > >
> > > > (if you grep Window you get false negatives because of the compression
> > > > window).
> > > >
> > > > Anyway, this is a lame attempt to prove the gtk stuff that does ui
> > (read:
> > > > uses X)
> > > > is separated in the code/architecture level :)
> > > >
> > > > >    So for me the shining light of spicec-gtk is not in "GTK" but in
> > "C".
> > > >  I
> > > > > dare not to say I'm clear about every nook in spicec at all. My best
> > hope
> > > > is
> > > > > that the IO in spicec shall be straight and succinct ,the inner
> > > > > graphic/sound computing(decompress,etc) shall have NO relation with
> > upper
> > > > UI
> > > > > libs at all, so I can pipe the Finished image flow into UI through
> > JNI
> > > > > interfaces and direct the user input backward.  (That's why I can
> > borrow
> > > > the
> > > > > UI from AndroidVNCViewer)
> > > >
> > > > Yeah, I think it is generally so, but again, it's so in spice-gtk too,
> > and
> > > > that's
> > > > our only future supported client (*).
> > > >
> > > > (*) plans do change.
> > > > >
> > > > >  libspicec.so(do most jobs)
> > > > > <==finishedimages/audio>>===<<inputs==>spicec.java.ui(only UI)
> > > > >
> > > > > Am I right? Is there any design that will frustrate this in spicec or
> > > > > spice-gtk?
> > > >
> > > > spicec is already separated at the platform level, since it uses low
> > level
> > > > libraries directly, unlike spice-gtk (X and GDI). So you would
> > basically
> > > > be adding a platform/android.
> > > >
> > > > In gtk I really haven't done android development, ever, at least not in
> > the
> > > > C level, but I was hoping:
> > > > Option 1: use spice-gtk with a gtk android backend
> > > > a) compiling gtk for it would be possible.
> > > > b) write a partial gtk backend, good enough for spice-gtk.
> > > > c) no changes to spice-gtk.
> > > >
> > > > Option 2 is of course to make spice-gtk also have platform separation,
> > > > while
> > > > still using gtk/gobject for all stuff that would Just Work when doing
> > 1.a
> > > > (the
> > > > data structures, the signals, the macros, the introspection?).
> > > >
> > > > >   Regards.
> > > > >
> > > > >
> > > > > On Fri, Mar 4, 2011 at 4:36 PM, Alon Levy <alevy at redhat.com> wrote:
> > > > >
> > > > > > On Fri, Mar 04, 2011 at 03:38:51PM +0800, Shuxiang Lim wrote:
> > > > > > > Hi all,
> > > > > > >    I'm trying these days to port spicec into Android.But it's a
> > > > rather
> > > > > > TOUGH
> > > > > > > way to go because the structure of spicec and android are
> > desperately
> > > > > > > inappropriate:the linux version of spicec is based on the
> > X11,which
> > > > is
> > > > > > not
> > > > > > > available in Android,thus the UI of spicec should be rewritten
> > from
> > > > > > > scratch...More troublesome is that the UI part and data part in
> > > > current
> > > > > >
> > > > > > Haven't looked at your proposal below yet, but did you check the
> > > > spice-gtk
> > > > > > work? maybe it is easier to start from that? are gtk libraries
> > > > available on
> > > > > > android? not talking about X. spice-gtk has objects for connection
> > and
> > > > > > channels
> > > > > > that afaik don't do any output, that's separate from the actual
> > widget
> > > > that
> > > > > > uses X. Also, gtk 3 has backends - did anyone do a backend for
> > android?
> > > > > >
> > > > > > Since going forward we plan to ditch the spicec client, that would
> > be
> > > > > > really
> > > > > > preffered. Now that I see what you have planned it sounds good, but
> > > > better
> > > > > > to use spice-gtk.
> > > > > >
> > > > > > of course that's not to say we won't love to see this working
> > anyway :)
> > > > > >
> > > > > > > spicec is entangled in the hierarchical system in C++! So my plan
> > is
> > > > > > this:
> > > > > > > first split the spicec into two parts,data and UI,transform the
> > data
> > > > part
> > > > > > > into libspicec.so;then rewrite the UI part in JAVA. Besides, I
> > should
> > > > > > also
> > > > > > > tinker some problems caused by the Crippled NDK C++ support and
> > the
> > > > Lamed
> > > > > > > bionic c lib in android .
> > > > > > >    And now the first step is roughly done,hence the change of the
> > > > spicec
> > > > > > > structure:
> > > > > > >    From
> > > > > > >
> > > > |-->playback
> > > > > > > thread
> > > > > > >
> > > > |-->cursor
> > > > > > > thread
> > > > > > > spicec:spicec process(application process)-->main
> > thread->|-->*record
> > > > > > thread
> > > > > > > *
> > > > > > >
> > > > |-->inputs
> > > > > > > thread
> > > > > > >
> > > > |-->display
> > > > > > > thread
> > > > > > > To:
> > > > > > > ===========================>
> > > > > > >                          |-->libspicec.so:application
> > thread-->main
> > > > > > > thread------>|
> > > > > > >                          |
> > > > > > > |
> > > > > > >                          |              |<--display thread<--|
> > > > > > >      |
> > > > > > >                          |         |--->|<--cursor
> > > > > > > thread<---|<------------------|
> > > > > > >                          |         |    |<--inputs thread<---|
> > > > > > > spicec:spicec process--->|         |    |<--playback thread<-|
> > > > > > >                          |         |
> > > > > > >                          |         |
> > > > > > >                          |         |
> > > > > > > <---------------------------------------------|
> > > > > > >                          |
> > > > > > >       |
> > > > > > >                          |
> > > > > > >       |
> > > > > > >                          |-->spicec:platform
> > > > > > > thread------------------------------>|
> > > > > > >
> > > > > > > The hierarchical relationship has been unleashed with one
> > > > thread(record
> > > > > > > channel) deleted and two new threads (app and platform)  created.
> > The
> > > > > > first
> > > > > > > as the "data thread",the other as the "work thread" which is
> > driven
> > > > by
> > > > > > the
> > > > > > > signals from the first thread as well as its sub threads and
> > > > requested to
> > > > > > do
> > > > > > > the UI-related work:
> > > > > > >
> > > > > > > platform thread:------------>blocked and waiting:-->job
> > > > > > > request-<--------------|
> > > > > > >                                           |           |
> > > > > > >                         |
> > > > > > >                                           ^           |
> > > > > > >                         |
> > > > > > >                                           |
> > > > > > > |                         |
> > > > > > >                                           |<----------|-<-|
> > > > > > >                     |
> > > > > > >                                                       |   |
> > > > > > >                 |
> > > > > > >         platform thread over<----------if(job==die)<--| send req.
> > > > blocked
> > > > > > > and waiting
> > > > > > >                                               |           ^ |
> > > > > > >     |
> > > > > > >                                               |           | |
> > > > > > >        ^
> > > > > > >                                               |           | |
> > > > > > > _________|_________
> > > > > > >                                               |           | |
> > > > > > > | app/plbk/cusor
> > > > > > > thd
> > > > > > >              |<---job done----dojob()<--else--|           | |->go
> > > > on->|
> > > > > > > __________________
> > > > > > >              |                                            |
> > > > > > >              |------------------------------->feed back-->|
> > > > > > >
> > > > > > >
> > > > > > > So the next work is to expose the native JNI interface in
> > platform
> > > > thread
> > > > > > to
> > > > > > > the UI written in Android SDK. I try to use the UI
> > > > > > > frame of AndroidVNCViewer in
> > > > > > > code.google.com/p/*android*-*vnc*-viewer/,then the work of
> > platform
> > > > > > > thread will be replaced by UI but the msg
> > > > > > > communication to libspicec will be remained. That's the easiest
> > way I
> > > > can
> > > > > > > envisage except rewriting all parts in spicec from scratch.
> > > > > > > It's tough too, for I have poor experiance in Java...
> > > > > > >    Anyway, is there any other guy working on this? Is my way
> > > > > > feasible??Any
> > > > > > > Ideas or help is appreciated.
> > > > > >
> > > > > > See above for ideas, don't read them as a criticism, I think this
> > is
> > > > > > fantastic
> > > > > > what you've done so far. I remember someone posting "we are working
> > on
> > > > > > andriod
> > > > > > in our spare time" post to spice-devel, please grep the archive.
> > > > > >
> > > > > > Alon
> > > > > >
> > > > > > >    Best regards.
> > > > > >
> > > > > > > _______________________________________________
> > > > > > > Spice-devel mailing list
> > > > > > > Spice-devel at lists.freedesktop.org
> > > > > > > http://lists.freedesktop.org/mailman/listinfo/spice-devel
> > > > > >
> > > > > >
> > > >
> > > > > _______________________________________________
> > > > > Spice-devel mailing list
> > > > > Spice-devel at lists.freedesktop.org
> > > > > http://lists.freedesktop.org/mailman/listinfo/spice-devel
> > > >
> > > >
> >
> > > _______________________________________________
> > > Spice-devel mailing list
> > > Spice-devel at lists.freedesktop.org
> > > http://lists.freedesktop.org/mailman/listinfo/spice-devel
> >
> >

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