RFR(S) 8230677: Should disable Escape Analysis if JVMTI capability can_get_owned_monitor_info was taken

[Vladimir Kozlov]

I read discussion and this change looks good to me.

May be add comment that it is onload capability and can't be changed during execution.

Thanks,
Vladimir

On 9/6/19 7:24 AM, Reingruber, Richard wrote:
> Hi,
> 
> could I please get reviews for
> 
> Webrev: http://cr.openjdk.java.net/~rrich/webrevs/2019/8230677/webrev.0/
> Bug:    https://bugs.openjdk.java.net/browse/JDK-8230677
> 
> The JVMTI functions GetOwnedMonitorInfo() and GetOwnedMonitorStackDepthInfo() can be used to
> retrieve objects locked by a thread. In terms of escape analysis those references escape and
> optimizations like scalar replacement become invalid.
> 
> The runtime currently cannot cope with objects escaping through JVMTI (try included
> tests). Therefore escape analysis should be disabled if an agent requests the capabilities
> can_get_owned_monitor_info or can_get_owned_monitor_stack_depth_info.
> 
> This was taken out of JDK-8227745 [1] to make it smaller. With JDK-8227745 there's no need to
> disable escape analysis, instead optimizations based on escape analysis will be reverted just before
> objects escape through JVMTI.
> 
> I've run tier1 tests.
> 
> Thanks, Richard.
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8227745
>