RFR 8210476: sun/security/mscapi/PrngSlow.java fails with Still too slow

[Xue-Lei Fan]

Do you know, is there any other way except Cleaner and finalize() to 
clean up the allocated resources?

I'm not very sure of the use of static Cleaner:
1. a daemon thread will run underlying.
2. the number of registered actions could be huge in some circumstances.

I'm not very sure if it could be a scalability bottleneck or not.

Xuelei


On 11/26/2018 5:33 PM, Weijun Wang wrote:
> Ping again
> 
>> On Nov 20, 2018, at 5:33 PM, Weijun Wang <weijun.wang at oracle.com> wrote:
>>
>> Webrev updated at
>>
>>    https://cr.openjdk.java.net/~weijun/8210476/webrev.01/
>>
>> The only change is that there is a single Cleaner now for the whole PRNG class. Otherwise, each will maintain its own thread.
>>
>> Thanks
>> Max
>>
>>> On Nov 11, 2018, at 11:30 PM, Weijun Wang <weijun.wang at oracle.com> wrote:
>>>
>>> Please take a review at
>>>
>>>   https://cr.openjdk.java.net/~weijun/8210476/webrev.00/
>>>
>>> Before this fix, every PRNG::nextBytes calls all of CryptAcquireContext, CryptGenRandom, and CryptReleaseContext. Now, CryptAcquireContext is called once in PRNG::new, and CryptReleaseContext is called by a Cleaner, and nextBytes only calls CryptGenRandom.
>>>
>>> I haven't read about thread-safety in any MS document, the current Windows-PRNG service is marked ThreadSafe=true (in SunMSCAPI.java). If we cannot be really sure, we can change it to false.
>>>
>>> I've downloaded nearly 1000 Mach5 runs of this test, the enhancement is so good that I adjusted the test to be stricter.
>>>
>>> 	Before	After
>>> 	------	-----
>>> Count	897	74
>>> Min	0.38	0.008
>>> Ave	0.97	0.011
>>> Max	5.81	0.021
>>>
>>> Please advise me if the following usage of Cleaner is correct because I really haven't observed the releaseContext method being called.
>>>
>>> +        Cleaner.create().register(this,
>>> +                () -> releaseContext(ctxt));
>>>
>>> Thanks
>>> Max
>>>
>>
>