RFR (S): 8230794: Improve assert to get more information about the JDK-8227695 failure

[Thomas Schatzl]

Hi Stefan, Kim,

   thanks for your reviews.

Thomas

On 9/10/19 3:36 PM, Kim Barrett wrote:
>> On Sep 10, 2019, at 6:20 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
>>
>> Hi all,
>>
>>   can I have reviews for this change that improves the assert that is
>> failing in JDK-8227695?
>>
>> We have been unsuccessfully trying to reproduce the problem locally and
>> doing tens of thousands runs with the original code to get a better
>> idea of the cause. (Or finding the issue with code inspection or by
>> tweaking the code)
>>
>> This change augments the assert to show more information, and adds it
>> in several places to get a better idea of the cause.
>>
>> It looks like this issue is caused by extremely specific environmental
>> conditions we were unable to reproduce.
>>
>> We will remove this debug code later.
>>
>> CR:
>> https://bugs.openjdk.java.net/browse/JDK-8230794
>> Webrev:
>> http://cr.openjdk.java.net/~tschatzl/8230794/webrev/
>> Testing:
>> hs-tier1-5 without failures :(
>>
>> Thanks,
>>   Thomas
> 
> Looks good.
>