[15] RFR 8238574: Shenandoah: Assertion failure due to missing null check

[Zhengyu Gu]

On 2/6/20 12:42 PM, Aleksey Shipilev wrote:
> On 2/6/20 6:34 PM, Zhengyu Gu wrote:
>> Please review this small change that adds a null check before calling
>> keep alive barrier to avoid assertion failure.
>>
>> Native barrier may return null for a not null oop, if it is dead.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8238574
>> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8238574/webrev.00/
> The patch looks good.
> 
> But I have a broader question: are all other paths that use the returned value from LRB-native safe?
> E.g. calling from assembler/C1/C2?

In C1/C2, we just make runtime call to this implementation.

-Zhengyu

> 
> Thanks,
> -Aleksey
>