Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 06 Oct 2000 09:48:35 -0700 (PDT)
From:      John Baldwin <jhb@FreeBSD.org>
To:        Bruce Evans <bde@zeta.org.au>
Cc:        cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org, Mike Smith <msmith@FreeBSD.org>
Subject:   Re: cvs commit: src/sys/alpha/include atomic.h src/sys/i386/incl
Message-ID:  <XFMail.001006094835.jhb@FreeBSD.org>
In-Reply-To: <Pine.BSF.4.21.0010062021030.2593-100000@besplex.bde.org>

next in thread | previous in thread | raw e-mail | index | archive | help

On 06-Oct-00 Bruce Evans wrote:
> On Thu, 5 Oct 2000, Mike Smith wrote:
> 
>> > > >>   Add atomic_readandclear_int and atomic_readandclear_long.
>> > ...
>> > It should be named loadandclear().  "load" is more precise than "read".
>> 
>> It should be called "atomic_exchange()", and this specific case should be 
>> 
>> int value = 0;
>> atomic_exchange(value, othervalue);
>> 
>> since it's otherwise entirely redundant.
> 
> Perhaps it should just be moved back to a machine-dependent place.  The
> machine might not have either an atomic exchange or an atomic exchange
> with 0.  I think it atomic_readandclear_int() is still only used in
> setdelayed(), which was MD, and setdelayed is only used in MD clock
> interrupt handler code.

It is used in the softinterrupt handler code (a trick I borrowed from the
alpha) as well as in setdelayed(), which is now a MI function.  All of the
setsoft*, schedsoft*, and setdelayed() are MI now.  They are software
interrupts, not hardware interrupts.
 
-- 

John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/
PGP Key: http://www.baldwin.cx/~john/pgpkey.asc
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?XFMail.001006094835.jhb>