From: kilgallen@eisner.decus.org (Larry Kilgallen)
Subject: Re: Waiver question
Date: 1997/05/02
Date: 1997-05-02T00:00:00+00:00 [thread overview]
Message-ID: <1997May2.164921.1@eisner> (raw)
In-Reply-To: E9KA78.DxH@world.std.com
In article <E9KA78.DxH@world.std.com>, bobduff@world.std.com (Robert A Duff) writes:
> Anyway, back to the point: Independent addressability does not imply
> task-safety. So, if variables are not automatically protected by
> locking/synchronization by default, it seems to me that they should not
> have to be independently addressable by default.
>
> In keeping with the principle you describe, above, I think I would
> prefer a language in which any variable that is potentially shared by
> multiple tasks would have to be explicitly declared "shared". But to do
A casual programmer would presume that if variable A is only modified
by task AA and variable B is only modified by task BB then they are
task-safe. This is not true if the variables share a longword on
Alpha. Having variables default to not sharing a longword goes a
long way toward eliminating this exposure.
Regarding Robert Dewar's comment about DEC changing their mind
with regard to byte instructions, I believe that was driven by
the need to emulate code compiled for Intel machines which had
never gotten recompiled specifically for Alpha. Market realities,
rather than machine efficiency are at play.
Larry Kilgallen
next prev parent reply other threads:[~1997-05-02 0:00 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
1997-04-18 0:00 Waiver question Ken Garlington
1997-04-19 0:00 ` Tom Moran
1997-04-20 0:00 ` Robert Dewar
1997-04-21 0:00 ` Ken Garlington
1997-04-22 0:00 ` Ken Garlington
1997-04-23 0:00 ` Corey Minyard
1997-04-24 0:00 ` Richard Kenner
1997-04-28 0:00 ` Larry Kilgallen
1997-04-28 0:00 ` Corey Minyard
1997-04-29 0:00 ` Robert Dewar
1997-04-29 0:00 ` Kaz Kylheku
1997-04-29 0:00 ` Laurent Guerby
1997-04-30 0:00 ` Corey Minyard
1997-04-29 0:00 ` Richard Kenner
1997-04-30 0:00 ` Robert Dewar
1997-05-01 0:00 ` Larry Kilgallen
1997-05-07 0:00 ` Bad .diff files in gnat-3.09 in Linux Benoit Jauvin-Girard
1997-05-09 0:00 ` Albert K. Lee
1997-04-30 0:00 ` Waiver question Robert A Duff
1997-05-01 0:00 ` Kaz Kylheku
1997-05-02 0:00 ` Robert A Duff
1997-05-02 0:00 ` Larry Kilgallen
1997-05-02 0:00 ` Robert Dewar
1997-05-02 0:00 ` Robert A Duff
1997-05-02 0:00 ` Larry Kilgallen [this message]
1997-05-03 0:00 ` Robert A Duff
1997-05-03 0:00 ` Larry Kilgallen
1997-05-04 0:00 ` Robert Dewar
1997-05-04 0:00 ` Robert Dewar
1997-05-06 0:00 ` John M. Mills
1997-04-29 0:00 ` Robert Dewar
1997-04-23 0:00 ` Tarjei Jensen
1997-04-20 0:00 ` Dean Runzel
1997-04-22 0:00 ` Ken Garlington
1997-04-20 0:00 ` Steve Doiel
1997-04-21 0:00 ` Robert I. Eachus
1997-04-21 0:00 ` Robert Dewar
1997-04-22 0:00 ` Robert I. Eachus
1997-04-23 0:00 ` Robert Dewar
1997-04-22 0:00 ` Ken Garlington
1997-04-23 0:00 ` Robert S. White
1997-04-24 0:00 ` Robert Dewar
1997-04-24 0:00 ` Steve Vestal
1997-04-25 0:00 ` Robert I. Eachus
1997-04-25 0:00 ` Ken Garlington
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