Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cwjcc!gatech!hubcap!wagner
From: wagner@june.cs.washington.edu (Bullwinkle J. Moose)
Newsgroups: comp.parallel
Subject: Re: Optimistic expression construct
Message-ID: <3604@hubcap.UUCP>
Date: 21 Nov 88 00:12:37 GMT
Sender: fpst@hubcap.UUCP
Lines: 20
Approved: parallel@hubcap.clemson.edu

In article <3532@hubcap.UUCP>, delagi@sumex-aim.stanford.edu (Bruce Delagi) writes:
> In languages supporting futures, one could write something like
> 
>      (let ((b (future ...some-expression...))
>            (c (future ...other-expression...)))
>        (if a (...an-expression-requiring-the-value-of-b)
>              (...an-expression-requiring-the-value-of-c)))
> 
> to get the effect of explicitly starting off optimistic calculations.  Only
> one of the calculations would need to return a value to return a value for
> the form as specified above.

Yes, but the unused calculation would continue to completion, which
could waste processor resources.


		Dave Wagner
		University of Washington Comp Sci Department
		wagner@cs.washington.edu
		{cornell,harvard,ssc-vax,tektronix}!uw-beaver!wagner