RFR (XS): JDK-8040977: G1 crashes when run with -XX:-G1DeferredRSUpdate

[Bengt Rutisson]

Hi Thomas,

On 2014-04-22 14:56, Thomas Schatzl wrote:
> Hi all,
>
>    can I have reviews for this change? It fixes wrong order of
> declaration of members of G1ParScanThreadState that causes crashes when
> G1DeferredRSUpdate is disabled.
>
> The change is based on the changes for 8035400 and8035401 posted recently.
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8040977
>
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8040977/webrev/

I realize that this fixes the code but I would really appreciate a more 
stable way of handling the dependencies.

As it it now we end up calling methods on a G1ParScanThreadState 
instance while we are setting it up. This seems broken to me and will 
probably lead to similar initialization order issues again. Best would 
be to not pass "this" to the constructor of G1ParScanClosure and instead 
manage the circular dependency between G1ParScanClosure and 
G1ParScanThreadState more explicitly after they have both been properly 
set up.

Second best would be to at least pass the worker id/queue num as a 
separate parameter to avoid having to call methods on an uninitialized 
object.

Thanks,
Bengt

>
> Testing:
> jprt, new jtreg test case
>
> Thanks,
>    Thomas
>
>
>