RFR (S): 8143215: gcc 4.1.2: fix three issues breaking the build.

[Thomas Schatzl]

Hi,

On Mon, 2015-12-14 at 13:03 +0100, Bengt Rutisson wrote:
> Hi Goetz,
> 
> On 2015-12-14 12:19, Lindenmaier, Goetz wrote:
> > Hi,
> >
> > I removed the change to g1CollectedHeap.cpp
> > ("8145303: Clean up the units for log_gc_footer" will fix this)
> > and changed the flag to 'double'. New webrev:
> > http://cr.openjdk.java.net/~goetz/webrevs/8143215-gcc412/webrev.05/
> 
> This looks good to me, but I haven't been following this thread closely 
> so it would be good if Kim and Thomas take a look too.
> 

 - I would prefer to keep CMSMaxAbortablePrecleanTime an integer value
(uintx/size_t) and then just cast for now. If we keep it a double, it is
imo a good idea to keep its max range to max_intx anyway. Using
MAX_DOUBLE will just cause grief for no gain.

One option would be to change the return value of
CMSPhaseAccounting::wallclock_millis() to an integer value (size_t?),
make CMSMaxAbortablePrecleanTime a size_t too, and cast in that method.
I do not see a problem with slight comparison result differences due to
truncating the double.

Kim might have some other preference.

 - in G1AdaptiveIHOPControl::get_conc_mark_start_threshold(), the
comment for the calculation of predicted_needed_bytes_during_marking
should be moved back closer to _last_unrestrained_young.

Maybe something like

size_t predicted_needed_bytes_during_marking =
  pred_promotion_size +
  // comment here
  _last_unrestrained_young_size;

The second cast in that same method could be avoided by making
_initial_ihop_percent an integer value. I am okay with the current way
too though.

Thanks,
  Thomas