Review request (M): 7085906: Replace the permgen allocated sentinelRef with a self-looped end

Jon Masamitsu jon.masamitsu at oracle.com
Tue Sep 6 09:49:11 PDT 2011


Looks good.

On 09/05/11 04:59, Stefan Karlsson wrote:
> http://cr.openjdk.java.net/~stefank/7085906/webrev/
>
> 7085906: Replace the permgen allocated sentinelRef with a self-looped end
>
> The reference processor uses the sentinelRef to mark the end of the 
> lists of discovered References. All the collectors rely on the 
> sentinelRef being allocated in the permgen, hence not moving. So, when 
> permgen is removed this will not work.
>
> We could probably make changes to the collectors to update all 
> pointers to the sentinelRef, but the proposed solution is to remove 
> the sentinelRef, and instead let the last Reference in a discovered 
> chain point back to itself. Just like we do with the next field.
>
> StefanK


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