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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.lang.c
Subject: Re: Volatile type in ANSI C
Message-ID: <5549@utzoo.UUCP>
Date: Sat, 27-Apr-85 19:29:53 EST
Article-I.D.: utzoo.5549
Posted: Sat Apr 27 19:29:53 1985
Date-Received: Sat, 27-Apr-85 19:29:53 EST
References: <543@lll-crg.ARPA>
Organization: U of Toronto Zoology
Lines: 16

> Looking at the description for the volatile type in the draft of the
> ANSI C standard there seems to be some incompleteness.
> The volatile type could have uses in multiprocessing where several
> processors share some data areas.  One could have volatile pointers to
> non volatile data areas (rarely) and more frequently nonvolatile pointers
> to volatile data areas that are shared with other processors.
> Does the ANSI C standard address these issues?

Yes.  It provides both.  "volatile int *foo;" declares a nonvolatile
pointer to volatile; "int * volatile foo;" declares a volatile pointer
to nonvolatile.  (Excuse me a moment while I barf over the syntax.)
If you're really a masochist, "volatile int * volatile foo;" is a
volatile pointer to a volatile area.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry