[jdk18] RFR: 8273383: vmTestbase/vm/gc/containers/Combination05/TestDescription.java crashes verifying length of DCQS

[Stefan Johansson]

On Tue, 18 Jan 2022 03:22:10 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

> I was planning to do that as one of several planned JDK 19 RFEs, while keeping the bug fix change minimal. If you prefer, I can bring forward the comment changes.
> 
I would prefer but if you plan bigger changes to the comments I'm fine with leaving it to 19.

> 
> The buffers that get pushed by enqueue_previous_paused_buffers were taken from the queue and paused before the previous safepoint. No thread can be in push/append or try_pop (via DCQS) across a safepoint boundary. So no ABA.
> 
I was mostly thinking about this case, that you mentioned. That for a short period of time after a safepoint some threads might still think they should yield. In that case it is not clear to me when such paused buffers would be re-added.

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PR: https://git.openjdk.java.net/jdk18/pull/104