RFR (XXS): 8057799: G1: unnecessary null check in G1KeepAliveClosure

[Stefan Karlsson]

Hi Tony,

On 2014-09-08 17:29, Tony Printezis wrote:
> (following a quick e-mail exchange with Thomas)
>
> Here's a small change to remove an unnecessary NULL check from 
> G1KeepAliveClosure:
>
> http://cr.openjdk.java.net/~tonyp/8057799/webrev.0/

Looks good.

I had to verify that G1StringDedup doesn't assert with this change. 
There's no explicit null-check in the code, but we don't set the oops to 
NULL G1StringDedupTable.

A side-note: I think this call to JNIHandles::weak_oops_do(&is_alive, 
&keep_alive) is not needed, since it's already cleaned during the 
reference processing:
void ReferenceProcessor::process_phaseJNI(BoolObjectClosure* is_alive,
                                           OopClosure* keep_alive,
                                           VoidClosure* complete_gc) {
...
   JNIHandles::weak_oops_do(is_alive, keep_alive);
   complete_gc->do_void();
}

thanks,
StefanK

>
> If I could get a couple of reviews and a volunteer to sponsor this, 
> it'd be awesome. :-)
>
> Thanks,
>
> Tony
>