jmx-dev RFR 7132590: javax/management/remote/mandatory/notif/NotificationAccessControllerTest.java fails in JDK8-B22

[Jaroslav Bachorik]

On 08/21/2014 05:34 PM, shanliang wrote:
> Jaroslav Bachorik wrote:
>> On 08/21/2014 03:55 PM, shanliang wrote:
>>> Jaroslav,
>>>
>>> The fix should be good to fix the failure.
>>>
>>> It makes me think a special case, suppose that the test waits 2
>>> notifications, but the test might receive one unexpected notification
>>> with some more waiting, for example, with the old version, 2 expected
>>> notifications arrive within the first second, and the unexpected arrives
>>> in the second second, but with your fix the test might end before the
>>> unexpected notification arrives.
>>
>> Hm, you mean providing a proof that extraneous notifications are not
>> emitted. I'm not really sure you can create such a proof for the
>> existing implementation - even if everything is fine within a certain
>> time window it does not imply that in the next n seconds an unexpected
>> notification wouldn't be delivered.
> Indeed, it is very difficult to make sure no unexpected notification,
> but the old version could by chance to get an unexpected because it
> waited always certain time.

IMO, getting something right by chance is even worse than simply stating 
that the test won't test for such eventuality.

>>
>>>
>>> Not sure that we should take care of this case.
>>
>> Probably not in this test. This test just asserts that all the
>> expected notifications have been emitted.
> No objection. This is a general issue for many other notification tests
> too.

In general it is impossible to test for extraneous notifications since 
there are no events cleanly defining the time boundaries for receiving a 
particular notification. The result is, that even though an extraneous 
notification hasn't been received in n seconds we can't be certain that 
one wouldn't arrive in n+m (m is a real number and m > 0) seconds.


Could I have a (R)eviewer to take a look at this patch, please?

-JB-

>
> Shanliang
>>
>> -JB-
>>
>>>
>>> Thanks,
>>> Shanliang
>>>
>>> Jaroslav Bachorik wrote:
>>>> Please, review the following test change.
>>>>
>>>> Issue : https://bugs.openjdk.java.net/browse/JDK-7132590
>>>> Webrev: http://cr.openjdk.java.net/~jbachorik/7132590/webrev.00
>>>>
>>>> Currently, the test waits for an arbitrary time until it gives up on
>>>> receiving the notifications. This leads to intermittent failures in
>>>> situations when the execution is slower than anticipated (running
>>>> against a debug build etc.).
>>>>
>>>> The solution is to block the test until all the expected notification
>>>> had been delivered or the test is timed out by the harness.
>>>>
>>>> Thanks,
>>>>
>>>> -JB-
>>>
>>
>