Date: Thu, 12 Mar 1998 21:15:25 +0100 (MET)
Message-Id: <199803122015.VAA29246@ask.diku.dk>
From: Morten Welinder <terra AT diku DOT dk>
To: sandmann AT clio DOT rice DOT edu
CC: Vik DOT Heyndrickx AT rug DOT ac DOT be, eliz AT is DOT elta DOT co DOT il, bill AT taniwha DOT tssc DOT co DOT nz,
        djgpp-workers AT delorie DOT com
In-reply-to: <9803121733.AA16133@clio.rice.edu> (sandmann@clio.rice.edu)
Subject: Re: Temporary files considered unsafe
Precedence: bulk


   True.  Things which are most likely to be unique:

   1) The cs selector value 
   2) The base virtual address of the cs selector
   3) PSP
   4) clock at startup

   A combination (sum? xor?) of these might be best for the PID.  There may
   be a pathaloigcal 1 in a million odds with something like this, but
   get a grip.

sum (which is monotonic) is better than xor for this kind of game.
As the Perl(?) docs mention, "x ^ y == (x + 1) ^ (y + 1)" entirely too
often.

Morten