JEP 193: Enhanced Volatiles

[Christoph Engelbert]

Am 05.03.2014 um 08:40 schrieb Jeroen Frijters <jeroen at sumatra.nl>:

>>  My goal here is to make sure that expert users can get their job done
>> somehow, *without* making the job of mainstream developers harder.  The
>> "add lvalues to Java so experts can write CAS-libraries" fails that test
>> miserably.
> 
> Why not go for something far less intrusive then? Here's my straw man proposal:
> 
> Add an annotation that can be placed on native methods to synthesize atomic accessor methods.
> 
> Example usage:
> 
> @AtomicField("next")
> private native boolean compareAndSet(Node expected, Node newValue);
> 
> @AtomicArray
> private static native boolean compareAndSet(Node[] array, Node expected, Node newValue);
> 
> (Note that the method name is not significant, the operation can be derived from the signature, or explicit in the annotation, if necessary.)
> 
> This requires no changes to the language and adds only a slight burden on the developer (but it's very easy to add tooling support). 
> 
> Regards,
> Jeroen
> 

That looks like a good fit towards what was mentioned earlier using method handles. The JVM or compiler could just look out for those annotations and generate corresponding method / field handles to execute it.

Thanks,
Chris