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

Ramki Ramakrishna y.s.ramakrishna at oracle.com
Mon Sep 5 10:38:49 PDT 2011


Stefan, this looks good to me. (PS: I am assuming this is substantively 
the same code I reviewed
last week? Let me know if there are any subsequent changes I need to be 
specially
aware of, or to pull into my testing.)

thanks!
-- ramki

On 9/5/2011 4:59 AM, 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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