RFR(S): 8026396 - Remove information duplication in the collector policy

[John Coomes]

Jesper Wilhelmsson (jesper.wilhelmsson at oracle.com) wrote:
> Hi,
> 
> Another step towards cleaner collector policy code.
> 
> This cleanup removes the need to keep the generation sizing flags in sync with 
> the collector policy version of the same variables during setup. The collector 
> policy variables are initialized in the start and then used throughout the setup 
> code. In the end we write the values back to the flags if needed.
> 
> This change builds upon the merged collector policy (8027643) currently in review.
> 
> Webrev: http://cr.openjdk.java.net/~jwilhelm/8026396/webrev/
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8026396

This looks good to me.

There seems to be a chance for underflow here:

534     _min_gen1_size = MIN2(_initial_gen1_size, _min_heap_byte_size - _min_gen0_size);

but your change is ok, since that also existed in the original code.

-John