RFR 8229958: Provider.getService() scalability issue for legacy algorithms and message digests

[Ivan Gerasimov]

Hi Letu!

The fix introduces a read of non-volatile variable legacyChanged outside 
of synchronized block, which is not guaranteed to produce consistent 
results.

(Please note that in the mentioned fix for JDK-7092821 the variable 
servicesChanged was made volatile, so that it could be accessed outside 
the synchronized blocks.)

With kind regards,

Ivan

On 8/20/19 10:18 PM, Yang, Letu wrote:
> Hi,
>
> Please review the fix of https://bugs.openjdk.java.net/browse/JDK-8229958 where I made the change to allow majority of calls don't have to acquire the locks when checking the availability of the Provider object. Similar effort had been made in fixing https://bugs.openjdk.java.net/browse/JDK-7092821 , but it only helped the calls for new encryption algorithms. Xin had helped me to upload the CR: https://cr.openjdk.java.net/~xliu/8229958/webrev/ .
>
> I had run tier-1 tests, and also a JMH test to confirm its performance improvement. We have also had it running in a load test environment of an application for a couple of days, and the improvement was confirmed as well.
>
> Best regards,
> Letu
>
-- 
With kind regards,
Ivan Gerasimov