RFR: JDK-8220671: Initialization race for non-JavaThread PtrQueues

[Kim Barrett]

> On Apr 1, 2019, at 5:45 AM, Roman Kennke <rkennke at redhat.com> wrote:
>> Here's the updated patch:
>> full: http://cr.openjdk.java.net/~kbarrett/8220671/open.01/
>> incr: http://cr.openjdk.java.net/~kbarrett/8220671/open.01.inc/
>> (The incremental patch might not be that interesting compared to the
>> full patch.)
>> The incremental patch adds a new mutex for the NJT synchronizer's
>> synchronize(). It also adjusts and/or moves around some comments. And
>> it adds ZGC code to protect against the same issue. I'm not sure the
>> ZGC code is in the right place (ZHeap); maybe it should be in
>> ZAddressMask instead? I'll let Per comment on that.
>> Testing: mach5 tier1-5.  I couldn't think of a good way to make a real
>> regression test here, because it's so timing sensitive.
> 
> Looks good to me. Thanks!
> 
> Roman

Thanks.