RFR 8006007: j.u.c.atomic classes should use intrinsic getAndXXX provided by 7023898

Aleksey Shipilev aleksey.shipilev at oracle.com
Thu Jan 10 19:48:50 UTC 2013

On 01/10/2013 09:15 PM, Chris Hegarty wrote:
> On 01/10/2013 05:05 PM, Aleksey Shipilev wrote:
>> On 01/10/2013 08:40 PM, Chris Hegarty wrote:
>>> Doug, Aleksey,
>>> I updated the appropriate methods in the Atomic classes to use the
>>> instinsics defined by 7023898 , Unsafe getAndAddInt, getAndSetInt,
>>> getAndAddLong, getAndSetLong, getAndSetObject.
>>> http://cr.openjdk.java.net/~chegar/8006007/webrev.00/webrev/
>> Good. Two comments:
>>   a) Any java-concurrency-torture [1] failures for these classes?
> Can you give me a brief introduction to running these? I have run the
> JDK regression tests and the appropriate JCK tests, all pass.

Build it, run it, see results/index.html. Should be 100% pass rate. If
not, drill down to exact tests.

>>   b) Can we delegate all the suitable methods to Unsafe directly, without
>> calling the middleman (i.e. getAndDec() -> getAndAdd() -> unsafe), as in
>> [2]?
> Yes, we could. The existing implementation was not consistent.
> I took the view that this was not performance critical, since some
> existing methods already delegate, and my preference, for simplicity, is
> for the middleman ;-) Do you think there is a perf benefit to changing
> this, or is this a style issue?

Yeah, that's mostly stylistic issue. If that's not in Doug's repo, you
can just disregard this. (There is a tempting desire to not to blow up
the call tree to help inliner, since the delegating method is not private).


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