Does openjdk8u need pre-barrier for jweak?

[Liu, Xin]

Agree. I will try to use the similar idea in G1. Aleksey, are you committer of JDK8u? I need to find a sponsor. 
IMHO, all concurrent GCs have this race condition, right?  Shall we fix CMS? 

Thanks,
--lx

On 8/15/18, 12:50 AM, "Aleksey Shipilev" <shade at redhat.com> wrote:

    Hi Kim,
    
    On 08/15/2018 07:01 AM, Kim Barrett wrote:
    > However, I think there might be a much simpler solution that retains
    > at least some clearing of jweaks.  Change the initial mark pause to
    > always scan and mark the JNI weak globals too, just as the normal JNI
    > globals are marked.  Leave process_phaseJNI alone (i.e. don't use
    > Shenandoah's patch.)
    
    That is actually a much saner idea for Shenandoah as well, thanks! Should have thought about it at
    the time. We have moved the workaround block to root processor, which can also distinguish between
    root processing for concurrent mark and last-ditch STW Full GC:
      http://mail.openjdk.java.net/pipermail/shenandoah-dev/2018-August/007094.html
    
    I think/agree we can apply similar workaround to G1, and move on.
    
    -Aleksey