An Alternative Hashing Alternative

[Rémi Forax]

On 06/06/2012 09:09 PM, Doug Lea wrote:
> On 06/06/12 15:03, Rémi Forax wrote:
>> tryMonitorEnter is the equivalent of tryLock for synchronized block
>> (monitorEnter/monitorExit).
>
> Sorry; yes. This method exists, but seems to be designed to only be used
> in unusual situations. So the performance is dreadful on JVMs I've
> tried it on. Working on this method to try to make it perform well
> enough to use in performance-sensitive code might make a good
> project for someone.
>
> -Doug
>

I've just checked Hotspot sources, monitorEnter/MonitorExit and 
tryMonitorEnter
have no corresponding intrinsic.
That's why you can't use them in ConcurrentHashMap.

Rémi