Request for review: 6806649

[David Holmes - Sun Microsystems]

Chris,

Looks good to me.

David Holmes

Christopher Hegarty - Sun Microsystems Ireland said the following on 
02/21/09 07:46:
> 6806649: synchronization bottleneck when constructing Thread subclasses
> 
> Webrev:
>   http://cr.openjdk.java.net/~chegar/6806649/webrev.00/webrev/
> 
> The global synchronization on Thread.subclassAudits at Thread 
> construction time has been discussed as a bottleneck:
> 
> http://cs.oswego.edu/pipermail/concurrency-interest/2009-February/005839.html 
> 
> 
> The implementation approach for this cache of subclass audits matches 
> the once-similar implementations in ObjectInputStream and 
> ObjectOutputStream, but since the 5056445 fix in JDKs 5.0u7 and 6, those 
> classes were changed to use a ConcurrentHashMap (with weakly referenced 
> Class keys) instead-- Thread should probably be changed similarly.
> 
> Thanks,
> -Chris.