RFR: 8249543: Force DirectBufferAllocTest to run with -ExplicitGCInvokesConcurrent

[Roger Riggs]

Hi,

RMI DGC relies only on WeakReferences so unless that is disabled, RMI 
should not see any difference.
The tests do provoke GC to run, so if it doesn't eventually clear weak 
refs (within a timeout) that would fail.

Thanks, Roger

On 7/16/20 3:09 AM, Alan Bateman wrote:
> On 15/07/2020 20:47, Roman Kennke wrote:
>> :
>> Why would it? Can you explain? (-ExplicitGCInvokesConcurrent is the
>> default for all GCs but Shenandoah, and has been that way forever. Do
>> you mean +ExplicitGCInvokesConcurrent?)
>>
> Just surprised that more tests aren't impacted. RMI DGC wouldn't work 
> with a STW collector if explicit GC were disabled. I haven't heard of 
> deployment using it with a concurrent GC but maybe it's okay. I'm just 
> surprised that the RMI tests in the jdk repo are robust enough to 
> pass, I would have guessed they might need attention (the test group 
> is jdk_rmi but it sounds like you might be running those already).
>
> -Alan