RFR: 8361099: Shenandoah: Improve heap lock contention by using CAS for memory allocation [v14]

[Xiaolong Peng]

On Tue, 6 Jan 2026 17:37:46 GMT, Kelvin Nilsen <kdnilsen at openjdk.org> wrote:

>> I'll add comments on this, _alloc_region_count == 0 means we don't want to use any shared alloc region, it will always allocate with a heap lock, ideally the performance should be same as before, so it always simply find a region with enough space and allocate in the region.
>
> Put the comments describing functions in the .hpp file, where they are currently.  But we need to enhance those comments.

I have added comments on those functions, I'll keep adding more for those missing comments; meanwhile I am trying to avoid excessive comment, pleas point out if any of the comments is not clear.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/26171#discussion_r2670355339