I'm submitting this fast-track with Solaris minor binding, scheduled to
timeout at 09/18/2009. I think the one pager explains the case for a
re-integration of this library. API info is put into materials directory.
Thanks,
Suresh
Template Version: @(#)sac_nextcase 1.68 02/23/09 SMI
This information is Copyright 2009 Sun Microsystems
1. Introduction
1.1. Project/Component Working Name:
libxklavier re-integration
1.2. Name of Document Author/Supplier:
Author: Suresh Chandrasekharan
1.3 Date of This Document:
10 September, 2009
4. Technical Description
2. Project Summary
2.1. Project Description:
X keyboard extension or XKB extends the ability to control
the keyboard over what is offered by the X Window System core
protocol. libxklavier, which's a utility library to make working
with XKB easier. We need this library for providing keyboard
selection support at GDM and for gnome keyboard switching
mechanism in the gnome desktop.
This one pager proposes re-integration of this library to
OpenSolaris 2010.02
2.2. Risks and Assumptions:
Solaris libxklavier and the dependent functionality of
gnome keyboard switching was enabled in S10 timeframe and
was later removed due to many customer complains of this
functionality not working as expected.
libxklavier is only extensively tested with Xorg based X
servers. Does not work well with Xsun. Also does not work with
remote displays.
Sparc Nevada systems which still have Xsun as the default
xserver will be EOLed soon. We are not planning to port
this to S10 updates. So the case for supporting Xsun based
servers directly is weaker than before.
Keyboard switching functionality was tested on Sunrays having
Xnewt xserver (derived from Xorg codebase) and found to be
working well.
For more information, look into the technical discussion of the
project in Section 4.1
3. Business Summary
3.1. Problem Area:
OpenSolaris marketing requires to modernize the input method
framework in the OpenSolaris PCD (INT-3 - Ensure maximum
compatibility with Linux based offerings in the area of input
methods and keyboard support.)
G11N is planning on transitioning the input method framework
from iiimf to ibus in OpenSolaris Next. Though ibus is a modern
input method framework with large community following, the
support for European input method is weak without the ability
to select the many available keyboard layouts using gnome
keyboard switcher.
Another requirement to have libxklavier delivered stems from
an effort to enhance LiveCD experience by providing the
keyboard/language selection in GDM screen. This also requires
libxklavier bindings.
3.2. Market/Requester:
OpenSolaris Marketing
3.3. Business Justification:
Needed for OpenSolaris modernization effort. LiveCD
modernization and input method framework change from
iiimf to ibus depends on this.
3.4. Competitive Analysis:
All the Linux distros which have Gnome as their desktop includes
libxklavier.
3.5. Opportunity Window/Exposure:
OpenSolaris 2010.02, gnome-2.28
3.6. How will you know when you are done?:
When libxklavier is integrated to OpenSolaris without any
P1/P2 open bugs at the time of integration.
4. Technical Description:
4.1. Details:
libxklavier is slightly controversial, but a very useful
library for keyboard swtiching.
libxklavier was integrated to Solaris in S10 timeframe, which
was removed later due to many complaints of the keyboard switching
functionality not working as expected.
From http://sac.sfbay/LSARC/2005/734/opinion.txt
........
4.8 libxklavier
libxklavier uses private XKB configuration files [22] that
are not safe to use, so if a user has a non-standard Xserver
or if a user is remote logged into a computer running a
different Xserver, keyboard switching will break. However,
many users who are use a supported Xserver obviously find
the ability to switch keyboard layout very useful.
"LSARC 2004/576 libxkbfile update for GNOME 2.6" discusses
the fact that Sun is now exposing the X header files used
by libxklavier, but this case does not highlight the fact
that this interface is considered private and unsupported
by X.org. Nor does this case discuss the issues caused by
using this interface discussed in this section.
The project team is Advised to drive resolution on this issue
with the community. The Xorg team is currently working on
a more Stable solution which the GNOME team should adopt
when it becomes available.
The project team is Advised to work with the Xorg Sun team
and the external Xorg and GNOME communities to facilitate
this work. The committee recommends that the Sun GNOME
team facilitate the adoption of a more stable interface to
support libxklavier functionality.
........
There has not been much progress in removing the limitations of
libxklavier in the community even after more than 4 years has
passed since the above case. Even though there are limitations
the advantages also seems to be too attractive to let this pass.
So the project team is planning to integrate this to OS 2010.02.
We currently have more than 460 keyboard layouts from the
community in OpenSolaris which needs libxklavier for accessing
them dynamically.
We looked in to the various issues filed which resulted in gnome
keyboard switcher mechanism and associated base library removal
and found that these are the major issues.
1. libxklavier does not work when XKB is disabled
2. libxklavier not work on Xsun
3. libxklavier does not work on remote displays
4. libxklavier uses private functions provided in libxkbfile library
All the above reported issues are right, they resulted from
the following broader issues
1. lack of adequate patches to fix/mask some of the issues
happening when XKB is disabled, Xsun is xserver and when
remote Xservers was employed..
2. lack of a opportunistic mechanism like dlopen/dlsym
based loading of the libxklavier library APIs
We think that through a combination of the above we can
harness the power of libxklavier without succumbing to
it's limitations.
For integration of the dependent functionality on libxklavier,
the project team advices the future projects based on libxklavier
to follow a 'do no harm' policy. (in our knowledge only gnome
keyboard switching and keyboard selection support at gdm are the
only 2 projects depending on this library however). This means
we need to mask the dependent functionality or provide patches
in cases where it does not work well.
Following are the issues and the solutions we foresee.
1. libxklavier does not work when XKB is disabled
libxklavier supports xkb and xmodmap through the use of
a compiler flag. When compiled with the default
"--enable-xkb-support" and if XKB is disabled in Xserver
keyboard switching does not work.
Advices project teams to tackle this by masking the keyboard
switching functionality in case we find XKB extension is
disabled in Xserver.
2. libxklavier does not work on Xsun
We are no longer constrained by Xsun as
i. We are not porting this library into S10 updates
where we still support Xsun Xserver
ii. OpenSolaris Xserver is based of Xorg, for both sparc/x86
Xsun is being EOFed.
iii. Nevada sparc is still Xsun, which will go away soon by the
time this project is integrated. Even if it won't we will
make sure keyboard switching is not enabled in Nevada
sparc systems
iv. Sunray Xserver is Xnewt which is based on Xorg codebase
primary test results of the test packages of
keyboard switching in Sunray seems to work fine.
3. libxklavier does not work on remote displays
libxklavier ignores the X-Window client-server model
and only reads the keyboard configuration files in the
client, not the xserver.
It's the current design limitation of the library
and a general limitation of X (and a security issue) when a
X client is displayed on a remote server, there is
no Xlib/XKB api's which will query for and read the
XML configuration files in the server from the client side.
Currently due to this issue the keyboard configuration
will be read from the client machine only. If server and client
is in the same machine, this works, otherwise this does not
unless the client and server machines are of identical
Xorg based configurations.
Disable keyboard switching functionality when the display
is remote is the solution.
4. libxklavier uses private functions provided in libxkbfile library
This is one of the long standing pain point and the reason
for libxklavier not tested and fixed in non-Xorg Xserver
like Xsun. libxkbfile is a private library used by
Xserver and some configuration utilities which never was
supposed to be used by others. libxklavier uses some of
the private APIs in libxkbfile.
Though 'private APIs from library libxkbfile' does not
seems to be right as LSARC/2004/576 gives 'External'
classification to libxkbfile and the associated headers,
which's not a private classification. Eventhough
libxkbfile originally was supposed to be a private
interface, it's not currently.
Gnome keyboard switching is used by heavily the community
and any change in the libxkbfile will cause an issue in
libxklavier used by linux communities and will be fixed,
we don't see this as a big enough issue which force us
not to use gnome keyboard switching functionality.
In addition to the above, project team is advicing future
consumers of libxklavier to opportunistically load the library
and APIs using dlopen/dlsym calls, instead of accessing the
library directly so that the associated functionality can be
disabled by either using an appropriate environment variable
or by removing libxklavier from the system in case of any
potential issues.
We are planning to bundle libxklavier 4.0 version with gnome 2.28
libxklavier will be delivered in SUNWlibxklavier
4.2. Bug/RFE Number(s):
6868433 Add gnome keyboard switcher
4.3. In Scope:
None
4.4. Out of Scope:
None
4.5. Interfaces:
Imported Interfaces
-------------------
Interface Stability Notes
--------- --------- -----
From LSARC/2004/576/
/usr/X11/lib/libxkbfile.so.5 External X.Org open
source implementation
XKB*.h headers External X.Org open
source implementation
Exported Interfaces
-------------------
SUNWlibxklavier
/usr/lib/libxklavier.so.15.0.0 Volatile library
/usr/lib/libxklavier.so.15 Volatile sym link
/usr/lib/libxklavier.so Volatile sym link
SUNWlibxklavier-devel
/usr/include/libxklavier/xkl-enum-types.h Volatile
Header File
/usr/include/libxklavier/xkl_config_item.h Volatile
Header File
/usr/include/libxklavier/xkl_config_rec.h Volatile
Header File
/usr/include/libxklavier/xkl_config_registry.h Volatile
Header File
/usr/include/libxklavier/xkl_engine.h Volatile
Header File
/usr/include/libxklavier/xkl_engine_marshal.h Volatile
Header File
/usr/include/libxklavier/xklavier.h Volatile
Header File
4.6. Doc Impact:
Documentation is provided with the SUNWlibxklavier-devel package,
included in
materials directory
6. Resources and Schedule
6.4. Steering Committee requested information
6.4.1. Consolidation C-team Name:
G11N
6.5. ARC review type: FastTrack
6.6. ARC Exposure: open
