RFR(XS): 8213898: CDS dumping of springboot asserts in G1ArchiveAllocator::alloc_new_region

[Thomas Schatzl]

Hi,

On Thu, 2018-11-15 at 10:05 -0800, Jiangli Zhou wrote:
> Please review the following small fix for the 
> assert(is_available(index)) failure when dumping the classes for 
> springboot (thanks Eric Caspole for reporting the issue!).
> 
>    webrev: http://cr.openjdk.java.net/~jiangli/8213898/webrev.00/
> 
>    bug: https://bugs.openjdk.java.net/browse/JDK-8213898
> 
> HeapRegionManager::find_highest_free is used by 
> G1ArchiveAllocator::alloc_new_region at CDS dump time for allocating
> a highest free GC region when archiving selected java heap objects.
> We need to check if the region obtained from the 
> HeapRegionManager::_regions is available, as it might be uncommitted 
> during heap shrinking. The fix has been reviewed by Thomas Schatzl
> in the bug report. Thanks Thomas!.

 looks good.

Thomas