From: stt@houdini.camb.inmet.com (Tucker Taft)
Subject: Re: Looking for implementation idea
Date: 1999/02/08
Date: 1999-02-08T00:00:00+00:00 [thread overview]
Message-ID: <F6tAGK.CsE.0.-s@inmet.camb.inmet.com> (raw)
In-Reply-To: m2r9s1hpn8.fsf@wf-rch.cirr.com
Corey Minyard (minyard@acm.org) wrote:
: stt@houdini.camb.inmet.com (Tucker Taft) writes:
: >
: > I'm curious -- where did you get the impression that protected
: > types did not work on a multiprocessor? I'm wondering how common
: > is this misconception...
: >
: Thanks for the reply. I would expect the average programmer would
: think of a protected type like a Java one, something more
: semaphore-like. I knew that it wasn't (and I know the reasons), but I
: would expect that when the average programmer puts something in a
: protected type they would expect it to be "protected" by mutex, which
: wouldn't happen on an SMP machine, but would on a uniprocessor one.
I've lost you here. What "wouldn't happen on an SMP machine?"
On an SMP operating system, O/S mutexes work across processors.
: So should I now put spin-locks in all my protected type operations so
: they will provide mutex on SMP machines (if mutex is what I am looking
: for, which I expect is their most common use)?
No, now I must have really confused you. The *implementation* of
protected types generally uses spin locks on a multi-processor (though
other mechanisms are also possible). The programmer need not worry
about this at all: mutual exclusion is provided by protected types, even
if there are multiple processors.
: --
: Corey Minyard Internet: minyard@acm.org
: Work: minyard@nortelnetworks.com UUCP: minyard@wf-rch.cirr.com
--
-Tucker Taft stt@averstar.com http://www.averstar.com/~stt/
Technical Director, Distributed IT Solutions (www.averstar.com/tools)
AverStar (formerly Intermetrics, Inc.) Burlington, MA USA
next prev parent reply other threads:[~1999-02-08 0:00 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
1999-02-07 0:00 Looking for implementation idea Thomas Handler
1999-02-07 0:00 ` Niklas Holsti
1999-02-08 0:00 ` Thomas Handler
1999-02-09 0:00 ` Niklas Holsti
1999-02-10 0:00 ` Thomas Handler
1999-02-07 0:00 ` Corey Minyard
1999-02-07 0:00 ` Larry Kilgallen
1999-02-08 0:00 ` dewar
1999-02-08 0:00 ` dennison
1999-02-08 0:00 ` robert_dewar
1999-02-07 0:00 ` Tucker Taft
1999-02-07 0:00 ` Corey Minyard
1999-02-08 0:00 ` Tucker Taft [this message]
1999-02-07 0:00 ` Corey Minyard
1999-02-08 0:00 ` robert_dewar
1999-02-08 0:00 ` dennison
1999-02-08 0:00 ` Tucker Taft
1999-02-09 0:00 ` robert_dewar
1999-02-11 0:00 ` Ehud Lamm
1999-02-08 0:00 ` robert_dewar
1999-02-07 0:00 ` Tom Moran
1999-02-07 0:00 ` Corey Minyard
1999-02-08 0:00 ` Thomas Handler
1999-02-07 0:00 ` Paul Duquennoy
1999-02-08 0:00 ` Thomas Handler
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