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

Daniel D. Daugherty daniel.daugherty at oracle.com
Thu Aug 20 20:49:23 UTC 2020


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



More information about the hotspot-runtime-dev mailing list