Subj : Re: CAS question
To   : comp.programming.threads
From : Joe Seigh
Date : Fri Mar 25 2005 06:52 pm

On Fri, 25 Mar 2005 22:30:34 -0000, Toby Douglass <toby.douglass@youknowwhattodo.summerblue.net> wrote:

> jseigh_01@xemaps.com wrote:
>
>> The argument expressions are evaluated before the function is called.  They
>> don't have to be atomic or anything.
>
> Is this true in all cases, though?  I don't know x86, but I could
> imagine that something simple like an addition or subtraction could be
> performed in situ on an operand to the atomic instruction.  In a
> hardware sense, it would just be a case of getting a ALU to perform an
> operation on an operand as it passes down the pipeline, which seems
> reasonable.
>
The api in question here is in C and that's how C works.  The
implementation does whatever it needs to do.

-- 
Joe Seigh

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