Path: utzoo!attcan!uunet!lll-winken!ames!mailrus!tut.cis.ohio-state.edu!bloom-beacon!SUN.COM!dshr
From: dshr@SUN.COM (David Rosenthal)
Newsgroups: comp.windows.x
Subject: Re: A Thought on X Terminals
Message-ID: <8902271538.AA07299@devnull.sun.com>
Date: 27 Feb 89 12:24:19 GMT
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 37

> Isn't David Rosenthal pointing to a basic limitation in the design of
> X rather than in the X terminal concept?
> 
> "...
> >	safely.  Overloading it with complex clients which use server
> >	resources to implement a high-performance graphical user interface
> >	is dangerous - clients will start to crash randomly (hardly
> >	user-friendly behaviour).  If all you want from X is a way of
> ..."

Right!

Or at least,  nearly right.  What I am pointing out is a fact of the
X protocol that makes the way that we currently write X clients unsafe,
in the sense that they may randomly crash through no fault of their own.
They are more likely to do so in an X terminal environment than in a
workstation environment - this is a practical not a fundamental difference
between the two environments,  but it does have practical effects for
customers.

Developing a whole new way of writing X clients is hard for both technical
and organizational reasons:

-	The current way has enormous momentum.
-	The technical difficulties of recovering from Alloc errors are
	enormous - no-one has even a theoretical structure for doing it.

In the meantime,  the only way of dealing with the problem is to avoid it
by providing the server with plenty of room to grow.  Plenty of room means
enough room so that Alloc errors never happen given the set of clients
that are normally run,  and the set of operator actions normally taken
(remember,  selections also take space in the server - what is the biggest
selection you think the user will make?).  Given my observations of actual
X servers running actual clients,  I believe that "plenty of room" is
at least 6-8meg.

	David.