RFR(XS): 8251179: Word tearing problem with _last_sweep

[David Holmes]

+1

Thanks,
David

On 7/08/2020 8:20 am, Coleen Phillimore wrote:
> 
> This looks good to me.  Thank you for fixing this!
> Coleen
> 
> On 8/6/20 6:09 PM, Markus Gronlund wrote:
>> Greetings,
>>
>> This is a follow-up to 8235573: Move JFR ObjectSample oop into 
>> OopStorage.
>>
>> As of JDK-8235573, the static variable _last_sweep in 
>> objectSampler.cpp can be modified and read concurrently. For 64 bit 
>> platforms, this isn't a problem but for 32 bit platforms that support 
>> concurrent weak reference processing, this could word tear. This 
>> change adds atomic accesses for said variable.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8251179
>> Webrev: http://cr.openjdk.java.net/~mgronlun/8251179/webrev00/
>> Testing: jdk_jfr
>>
>> Thank you
>> Markus
>