RFR 10 JDK-8159995: Rename internal Unsafe.compare methods
ron.pressler at oracle.com
Wed May 10 20:57:07 UTC 2017
Your comments, and Paul's, have all been addressed in a revised patch
On 08/05/2017 08:30, David Holmes wrote:
> Hi Ron,
> On 6/05/2017 5:27 AM, Ron Pressler wrote:
>> Please review the following core/hotspot change:
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8159995
>> core webrev:
>> hotspot webrev:
>> This change is covered by existing tests.
>> The following renaming was applied:
>> - compareAndExchange*Volatile -> compareAndExchange*
>> - compareAndSwap* -> compareAndSet*
> So to clarify this for others, there was confusion surrounding the use
> of "swap" versus "exchange" when both words mean the same thing
> effectively, but the "swap" functions return a boolean, while the
> "exchange" functions return the old value. So we changed "swap" to
> "set" across the APIs - _except_ for the old
> /jdk.unsupported/share/classes/sun/misc/Unsafe.java because we can't
> change its exported API for compatibility reasons.
> Given any "swap(exp, new)" function can be implemented as
> "exchange(exp, new) == exp" I'm not sure why we have two complete sets
> of functions all the way through. But I guess that is a different
> issue. :)
>> - weakCompareAndSwap* -> weakCompareAndSet*Plain
>> - weakCompareAndSwap*Volatile -> weakCompareAndSet*
>> At this stage, only method and hotspot intrinsic names were changed;
>> node names were left as-is, and may be handled in a separate issue.
> Overall looks good for libs and hotspot changes.
> One nit I spotted:
> + * compareAndSwap for longs. While the intrinsic compareAndSetLong
> compareAndSwap should be compareAndSet
> All hotspot files need their copyright years updated to 2017 (if not
> As there are hotspot changes this must be pushed using JPRT and
> "-testset hotspot" (but your sponsor should know that :) ).
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