RFR (M): CR 8003985: Support @Contended Annotation - JEP 142

[Aleksey Shipilev]

Thanks for review, Christian!

On 11/29/2012 10:28 PM, Christian Thalinger wrote:
>> The webrev for the change is here:
>>  http://shipilev.net/pub/jdk/hotspot/contended/webrev-4/
> 
> Is this a review for a push?

Yes, I'm pretty much done with functionality, it passes the tests, and
flies through JPRT without problems.

> hotspot/src/share/vm/classfile/classFileParser.cpp:
> 
> Is it possible to factor the while-loop to align the fields into a method?

The whole method ClassFileParser::parseClassFile cries for refactoring.
Alas, separating the contended handling code would be more messy than
just fitting in the same flow, since it uses quite of few locals within
that method.

> hotspot/src/share/vm/classfile/classFileParser.hpp:
> 
> +    bool hasContendedAnnotation() { return has_annotation(_sun_misc_Contended); }
> 
> We don't use camel-case method names.

OK.

> hotspot/src/share/vm/classfile/vmSymbols.hpp:
> 
> Please keep the indent aligned.

OK.

> hotspot/src/share/vm/oops/fieldInfo.hpp:
> 
> I wonder if we have a spare access_flags bit somewhere we could use for is_contended.

Looking at jvm.h, I see there is only single bit left, want me to burn
it with contended flag?

> jdk/src/share/classes/sun/misc/Contended.java:
> 
> Misses copyright header.

Will update.

-Aleksey.