RFR: 8028391 - Make the Min/MaxHeapFreeRatio flags manageable

[Staffan Larsen]

Jesper,

This looks ok from a serviceability perspective. Long term we should probably have a more pluggable way to verify values of manageable flags so we can avoid some of the duplication.

I have a slight problem with is_within() and is_min() in that it is not obvious from the call site if the min and max values are inclusive or not - it was very obvious before.

/Staffan 


On 21 jan 2014, at 22:49, Jesper Wilhelmsson <jesper.wilhelmsson at oracle.com> wrote:

> Hi,
> 
> Could I have a few reviews of this change?
> 
> Summary:
> To allow applications a more fine grained control over the GC over time, we'll make the flags MinHeapFreeRatio and MaxHeapFreeRatio manageable.
> 
> The initial request that lead up to this change involved ParallelGC which is notoriously unwilling to shrink the heap. Since ParallelGC didn't support the heap free ratio flags, this change also includes implementing support for these flags in ParallelGC.
> 
> Changes have also been made to the argument parsing, attach listener and the management API to verify the flag values when set through the different interfaces.
> 
> Webrev: http://cr.openjdk.java.net/~jwilhelm/8028391/webrev.4/
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8028391
> 
> The plan is to push this to 9 and then backport to 8 and 7.
> 
> Thanks!
> /Jesper