RFR 8231999: Shenandoah: Traversal failed compiler/jsr292/CallSiteDepContextTest.java

[Roman Kennke]

>> So for traversal, it falls to the normal LRB, is that what you intended?
> 
> It is always the case, isn't it?

Yeah sure, just wanted to check if that is what you intended.

The patch is ok. Ideally, the code that calls into GC path wouldn't go
through the barrier to begin with, though. Can you keep a record of
which code path does that?

Roman

> 
> 
> -Zhengyu
> 
>>
>> Roman
>>
>>> This patch partially reverts JDK-8231293's fix, because it hides dead
>>> oops from GC, by returning NULL, which causes the failure of this test
>>> case.
>>>
>>> The root cause of JDK-8231293 is that, Traversal deactivates SATB
>>> barrier too late, it should be turned off before weak root processing.
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8231999
>>> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8231999/webrev.00/
>>>
>>> Test:
>>>    hotspot_gc_shenandoah (fastdebug and release) on Linux
>>>
>>> After this fix, CallSiteDepContextTest.java test hangs in traversal
>>> mode, but it is separate issue, tracked by JDK-8232380.
>>>
>>> Thanks,
>>>
>>> -Zhengyu
>>>
>>>
>>>
>>