RFR: 8256050: JVM crashes with -XX:+PrintDeoptimizationDetails

[Vladimir Kozlov]

On Mon, 9 Nov 2020 13:01:18 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

> -XX:+PrintDeoptimizationDetails triggers intermittent crashes. I spotted 2 independent problems which the patch addresses:
>   * `markWord::print_on` doesn't handle displaced header case well (the pointer stored in the header may be stale);
>   * `InstanceKlass::oop_print_value_on` dumps some specific details about `MemberName`, but the code assumes the instance is fully initialized. It's necessarily the case: for example, deoptimization can happen when `MemberName` constructor is being executed.  
> 
> Testing:
> - [x] manually verified that the crashes go away -XX:+PrintDeoptimizationDetails
> - [x] hs-precheckin-comp,hs-tier1,hs-tier2

Good.

-------------

Marked as reviewed by kvn (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/1124