RFR(XL): 8167108 - SMR and JavaThread Lifecycle

[David Holmes]

On 12/10/2017 1:32 AM, coleen.phillimore at oracle.com wrote:
> 
> Hi,  From my initial look at this, I really like new interface for 
> walking the threads list, except every instance but 2 uses of 
> JavaThreadIterator has a preceding ThreadsListHandle declaration.
> 
> +  ThreadsListHandle tlh;
> +  JavaThreadIterator jti(tlh.list());
> 
> 
> Could there be a wrapper that embeds the ThreadsListHandle, like:
> 
> class JavaThreadsListIterator {
>      ThreadsListHandle _tlh;
> ...
> }

The ThreadsListHandle could not itself be a stack-object in that case.

David

> Thanks,
> Coleen
> 
> On 10/9/17 3:41 PM, Daniel D. Daugherty wrote:
>> Greetings,
>>
>> We have a (eXtra Large) fix for the following bug:
>>
>> 8167108 inconsistent handling of SR_lock can lead to crashes
>> https://bugs.openjdk.java.net/browse/JDK-8167108
>>
>> This fix adds a Safe Memory Reclamation (SMR) mechanism based on
>> Hazard Pointers to manage JavaThread lifecycle.
>>
>> Here's a PDF for the internal wiki that we've been using to describe
>> and track the work on this project:
>>
>> http://cr.openjdk.java.net/~dcubed/8167108-webrev/SMR_and_JavaThread_Lifecycle-JDK10-04.pdf 
>>
>>
>> Dan has noticed that the indenting is wrong in some of the code quotes
>> in the PDF that are not present in the internal wiki. We don't have a
>> solution for that problem yet.
>>
>> Here's the webrev for current JDK10 version of this fix:
>>
>> http://cr.openjdk.java.net/~dcubed/8167108-webrev/jdk10-04-full
>>
>> This fix has been run through many rounds of JPRT and Mach5 tier[2-5]
>> testing, additional stress testing on Dan's Solaris X64 server, and
>> additional testing on Erik and Robbin's machines.
>>
>> We welcome comments, suggestions and feedback.
>>
>> Daniel Daugherty
>> Erik Osterlund
>> Robbin Ehn
>