RFR: 8205577: parallel/TestPrintGCDetailsVerbose.java fails assertion

[Kim Barrett]

> On Jun 27, 2018, at 3:30 AM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> Hi,
> 
> On Wed, 2018-06-27 at 01:03 -0400, Kim Barrett wrote:
>> Please review this fix of an assertion failure during ParallelGC
>> young collections.
>> 
>> We have a task (thread) walking the code cache, copying and
>> forwarding oop references in those cached nmethods containing
>> scavengable (e.g. young) oops.  After the oops in an nmethod are
>> processed, a second pass is made to determine whether any of the oops
>> are still scavengable, removing the nmethod from the list containing
>> scavengable oops.  That speeds up future collection cycles.
>> 
> [...]
>> The solution being taken here is to change that logging to no longer
>> attempt to print the object.  Printing an object while in the middle
>> of a copying GC, especially one that is parallel, seems quite risky,
>> so let's just not do that.
> 
> Looks good.
> 
> Thomas

Thanks.