[jmm-dev] bitwise RMW operators, specifically testAndSetBit/BTS

Hans Boehm boehm at acm.org
Fri Jul 22 21:51:03 UTC 2016


"Word-tearing" was definitely and consistently used that way in the JSR 133
discussions.  That's where the JLS terminlogy came from.  But people I've
talked to who didn't participate in that effort generally seemed to share
Martin's opinion.

On Fri, Jul 22, 2016 at 1:29 PM, Martin Buchholz <martinrb at google.com>
wrote:

>
>
> On Wed, Jul 20, 2016 at 10:16 PM, David Holmes <david.holmes at oracle.com>
> wrote:
>
>> On 21/07/2016 4:20 AM, Hans Boehm wrote:
>>
>>> You are not alone.  I have the suspicion that "word tearing" used to mean
>>> 17.7 before the 2005 JLS revision.  But the JLS usage seems to have won,
>>> for better or worse, at least in Java circles.
>>>
>>
>> No not at all. word-tearing has "always" concerned the inability to
>> perform sub-word atomic accesses - ie the subword has to be torn out of the
>> word.
>>
>> Here's a 2001 reference which was part of the discussion that led to the
>> JLS update :)
>>
>> http://www.cs.umd.edu/~pugh/java/memoryModel/archive/0967.html
>
>
> Thanks for the history lesson.  "word tearing" still seems unintuitive to
> me - it's the INability to tear up a word into sub-words that's the
> problem.  That is, "word tearing" is not the problem, it's the solution we
> can't use!  But my own "word bleeding" is also not that great, and unlikely
> to catch on.
>


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