[TUHS] X, Suntools, and the like

Nick Downing downing.nick at gmail.com
Wed Mar 15 11:13:04 AEST 2017

Hmm yes although perhaps controversially I see this as a bad feature and
one area where Microsoft actually gets it right. Despite the old issues of
"DLL Hell" which have largely been resolved by standardizing all DLLs and
in newer code by using assemblies... you have to admit that they provide a
direct, local API (indeed ABI) to every subsystem you would want to use,
here I am thinking of GDI, but also lots of things that would require
ioctls (CD burning, say) or domain specific languages (such as Postscript)
on Linux. This makes it really easy for Windows developers to use the
feature and the interface is fast and reliable. And where a domain specific
language is actually NEEDED (printing to a Postscript printer on Windows,
or RDP-type desktop remoting etc) it is easy to insert a proxy DLL or
object or device driver that does the necessary scrambling and
unscrambling. It is not so easy to go the other way as it requires
extensive emulation (think of ghostscript driving my Canon non-PS printer).

I wrote about this issue earlier using some examples like an "ESC ["
capable terminal as opposed to a memory mapped local console, or an "AT"
capable external modem as opposed to an internal "WinModem" that just
exposes its D/A and A/D converters with minimal signal processing and needs
the host to do the heavy lifting. Same thing applies to a graphics
terminal. Of course it should be programmed at a high level by specifying
shapes, etc to be drawn, regions to be blitted, clipping regions and pens
etc, a font manager, and it should be possible to load bitmaps, etc, into
its offscreen memory and/or create offscreen drawing buffers, if these
features are used correctly by applications then it is of course trivial to
add a remoting proxy driver similar to Microsoft's RDP, or indeed X Windows.

But the difficulty with X Windows is that the remoting layer is always
there, even though it is almost completely redundant today. This hurts
performance but more importantly it requires extensive workarounds as you
described, which add enormous extra complexity and in my view sharply
increase the learning curve and setup costs. Having said that, Xlib does
offer a decent API/ABI so if we just code to that it's not TOO bad, I would
like to see the rest of it deprecated though, and vendors encouraged to
implement Xlib with whatever backend seems appropriate.

The ridiculous thing here is that X setup is so damn convoluted and
incestuously tied in with the window, session and display managers, THAT IT
have tried many times and have had various tries at thin clients and
terminal serving in my home network and it basically fell over because
environments like Gnome do not support multiple sessions of the same home
directory, not to mention numerous other problems that mean if you login
remotely you basically just get a blank screen with a default X cursor and
maybe a context menu that can run an Xterm. Bleh! In my experience you have
to use a remoter like VNC and guess what that does, tricks X into thinking
it's running locally and then intervenes further up in the display stack to
do the actual remoting.

It's a complete dog's breakfast and frankly could never compete with
Windows in any realistic way. I use it because it is the least bad of the
available options (no way am I having advertising in my start menu and my
computer loaded with bloatware and spyware before I even open the box, and
no way am I putting up with vague messages like "Something went wrong" or
"Windows is making some checks to optimize your experience" or whatnot),
and because my computer is so fast despite being 6yrs old that X only feels
borderline sluggish, i.e. is tolerable. But so much better would be
possible with a redesign. CUPS is also a dogs breakfast and hugely
unreliable, Windows GDI printing just wins hands down for all the same
reasons. End rant.


On Mar 15, 2017 5:49 AM, "Ron Natalie" <ron at ronnatalie.com> wrote:

Nice thing about X was that it would talk to remote displays.    I still
remember sitting in the Pentagon demonstrating that the Suntools screen
lock wasn't particularly secure.
Then there was NeWS.   This was Gosling's first attempt at a deployable
language.    However PostScript (even with Owen Densmore's class
extensions), while a reasonable intermediary language is really sucky to
actually develop.   Java was a bit more refined.

Of course, lots of things either implement X under the native window system
or backdoor X with local extensions.    We got around doing high frame rate
image work on X via the SharedMemoryExtension and the ability to flip
buffers on the retrace interval (both extensions, but commonly implemented
by many servers).
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