[sh/jdk11u]: JVMTI related backports

[Zhengyu Gu]

On 3/3/20 8:28 AM, Aleksey Shipilev wrote:
> That is fine. Please consider pushing the other one, though.

Most of jvmti failures are exhibited by JDK-8237396, so I think should 
get them in once.

-Zhengyu

> 
> On Tue, Mar 3, 2020 at 2:17 PM Zhengyu Gu <zgu at redhat.com 
> <mailto:zgu at redhat.com>> wrote:
> 
>     Hi Aleksey,
> 
>     Lost your reply in inbox somehow.
> 
>       > If we want to cherry-pick 8237396 ahead of 11u, we have to
>     protect it
>       > with UseShenandoahGC. I think
>       > like this:
> 
>     I will wait jdk11u backport to arrive, so hold off this backport.
> 
>     Thanks,
> 
>     -Zhengyu
> 
> 
>     On 2/28/20 4:37 PM, Zhengyu Gu wrote:
>      > I would like to backport these two JVMTI heap walk related backports:
>      >
>      > 8237396: JvmtiTagMap::weak_oops_do() should not trigger barriers
>      > 8237632: Shenandoah: accept NULL fwdptr to cooperate with JVMTI
>     and JFR
>      >
>      > The backports clear JVMTI related test failures.
>      >
>      > Webrev:
>      > http://cr.openjdk.java.net/~zgu/shenandoah/jvmti_sh_jdk11u/webrev.00/
>      >
>      > Test:
>      >    hotspot_gc_shenandoah
>      >    vmTestbase_nsk_jvmti
>      >    vmTestbase_nsk_jdi
>      >
>      > Thanks,
>      >
>      > -Zhengyu
>      >
>      >
>