RFR(T): 8252126: 'GVars.stw_random = os::random()' lost by JDK-8246476

[Daniel D. Daugherty]

Thanks for the fast review Erik!

Dan

On 8/20/20 4:53 PM, Erik Österlund wrote:
> Hi Dan,
>
> Looks good.
>
> Thanks,
> /Erik
>
>> On 20 Aug 2020, at 22:49, Daniel D. Daugherty <daniel.daugherty at oracle.com> wrote:
>>
>> Greetings,
>>
>> Thanks to Erik O. for spotting this lost line of code!
>>
>> I have a trivial fix for a piece of code that was accidentally lost with
>> the push of another ObjectMonitor fix (8246476). Here's the bug ID for
>> restoring the line of code:
>>
>>      JDK-8252126 'GVars.stw_random = os::random()' lost by JDK-8246476
>>      https://bugs.openjdk.java.net/browse/JDK-8252126
>>
>> And here's the context diff for the trivial change itself:
>>
>> $ hg diff -r qparent
>> diff -r 8f73aeccb27c src/hotspot/share/runtime/synchronizer.cpp
>> --- a/src/hotspot/share/runtime/synchronizer.cpp    Thu Aug 20 11:12:00 2020 -0700
>> +++ b/src/hotspot/share/runtime/synchronizer.cpp    Thu Aug 20 16:40:10 2020 -0400
>> @@ -2322,6 +2322,8 @@
>> Atomic::load(&om_list_globals._free_count),
>> Atomic::load(&om_list_globals._wait_count));
>>
>> +  GVars.stw_random = os::random();
>> +
>>     // The ServiceThread's async deflation request has been processed.
>>     _last_async_deflation_time_ns = os::javaTimeNanos();
>>     set_is_async_deflation_requested(false);
>>
>>
>> I've added a couple of analysis comments to the bug report for anyone
>> that wants to read the gory details.
>>
>> This fix has been tested as part of a larger ObjectMonitor fix that
>> will take some time to get through the code review, stress test and
>> performance testing process.
>>
>> Thanks, in advance, for any comments, questions or suggestions.
>>
>> Dan
>>