Re: R?f?. : Re: [Bug-gnubg] Tutor/Analysis

[Jim Segrave]

On Fri 03 Oct 2003 (13:58 +0000), Joern Thyssen wrote:
> On Fri, Oct 03, 2003 at 03:31:29PM +0200, Jim Segrave wrote
> > On Fri 03 Oct 2003 (13:44 +0200), Nardy Pillards wrote:
> > 
> > I'm less pessimistic than Joern, I think it's possible that after the
> > storage of move records has had some rework it may eventually be
> > possible to do this. 
> > 
> > While writing this, another approach has occurred to me which is
> > either kind of slick or horribly awful:
> > 
> > [warning - delving off into technical issues here, backgammon players
> > need not read further]
> > 
> > Suppose one didn't try to thread gnubg, but instead (when auto-analyse
> > is selected) simply forked when starting a match or session. The child
> > process would be the analyser and would do whatever's needed to close
> > any gui or cli interfaces.
> > 
> > Have a shared memory segment for completed moves, so when the playing
> > side of gnubg was ready to add a move to the list, it obtained a lock,
> > added the move and released it. Moves are only written by the parent
> > process except at very specific times when copying the analysis
> > results back to the parent.
> [snip]
> 
> Your suggestion is basically some async master/slave process:
> 
> The master request an analysis from the slave
> The master goes on doing what it needs to do
> The master asks for the previous analysis and requests a new one
> ....
> 
> 
> The alternative way is having a thread that sneaks around and analyses
> any un-analysed moverecords.

Yes, but because it's forked, it has a private copy of everything and
changes in the parent (like fiddling with settings) are no longer
relevant. It's sort of poor man's threading  - no extra effort to
identify variables which need to be protected/locked or whatever. 

The obvious extension is to replace the child process with a network
socket into which you push new moves with an identifier (or delete
previous ones) and a client that sends back analysed moves. 

Then you do this on a per game basis to a network of analysing
machines.

Then you make it into a screen saver

Joseph uses it to do the .15 net, using the screen savers of 200,000
PCs around the world. 

Anyway, enough daydreaming and back to work...


-- 
Jim Segrave           address@hidden