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

[Erik Österlund]

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
>