RFR: String deduplication for traversal GC

[Zhengyu Gu]

On 01/30/2018 02:48 PM, Roman Kennke wrote:
> Am 30.01.2018 um 20:46 schrieb Roman Kennke:
>> Am 30.01.2018 um 20:40 schrieb Zhengyu Gu:
>>> Please review the implementation of string deduplication for 
>>> traversal GC.
>>>
>>>
>>> Webrev: 
>>> http://cr.openjdk.java.net/~zgu/shenandoah/traversal_dedup/webrev.00/
>>>
>>>
>>> Test:
>>>
>>>    hotspot_gc_shenandoah (fastdebug + release)
>>>    specJVM with -XX:+UseStringDeduplication (fastdebug)
>>>
>>>
>>> Thanks,
>>>
>>> -Zhengyu
>>
>> I wonder if it should be possible to make the closure templated 
>> instead of making multiple explicit classes, like this:
>>
>> template <bool STRDEDUP>
>> class ShenandoahTraversalSuperClosure .. {
>>
>> ..
>>     template <class T>
>>     void work(T* p);
>> }
>>
>> and then something like:
>>
>> template <bool STRDEDUP>
>> class ShenandoahTraversalDedupClosure : public 
>> ShenandoahTraversalSuperClosure<STRDEDUP> {
>>
>> I am not totally sure about how to stitch it together, but something 
>> like this should work? Or maybe it's not worth all the hassle. ?
>>
>> (Infact, I suspect something like the above would be possible for the 
>> metadata flag too...)
>>
>> Roman
>>
> 
> 
> Ah, one weirdo in this scheme is the definition of work(), which would 
> look something like:
> 
> template <bool STRDEDUP>
> template <class T>
> inline void ShenandoahTraversalSuperClosure::work(T* p) {

What's advantage of this style?

Thanks,

-Zhengyu


> 
> Roman