RFR: 8055702 - Remove the generations array

[Mikael Gerdin]

Hi Jesper,

On Friday 22 August 2014 15.20.15 Jesper Wilhelmsson wrote:
> Hi,
> 
> This is the first part of the generation array removal. Here I remove the
> _gens array and introduce _young_gen and _old_gen instead. The main change
> is in GenCollectedHeap::do_collection() which used a loop to iterate
> through the generation array. I extracted the contents of that loop into a
> new method and call it with a reference to the generation to be collected.
> 
> Webrev: http://cr.openjdk.java.net/~jwilhelm/8055702/webrev/

There are still some strange bits and pieces in the code but overall I think 
this is a nice cleanup.

Reviewed.

/Mikael

> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8055702
> 
> 
> More cleanups in this area are coming. Among other things I will remove from
> GenCollectedHeap: _n_gen, SomeConstants, get_gen(), next_gen(), prev_gen(),
> n_gens() and the concept of levels that is passed around all over the
> place. These will be replaced with a more explicit use of young and old as
> appropriate.
> 
> All that is actually already done, it just needs to be split into more
> reviewable changes. Stay tuned.
> 
> Thanks,
> /Jesper