RFR: 8189088: Add intrusive doubly-linked list utility [v7]

[Kim Barrett]

On Tue, 17 Oct 2023 07:46:33 GMT, Stefan Johansson <sjohanss at openjdk.org> wrote:

>> src/hotspot/share/utilities/intrusiveList.hpp line 87:
>> 
>>> 85:  * * Base is the base class for the list.  This is typically
>>> 86:  * used to specify the allocation class, such as CHeapObj<>.  The default
>>> 87:  * is void, indicating the list is not derived from an allocation class.
>> 
>> I'm not certain this Base class for allocation support is actually needed.  I remember one of the alternatives had
>> (or used to have?) allocation base class support, but haven't found it when I looked recently.  But we have a lot
>> of these doubly-linked-lists in HotSpot.  Do we have a use-case for a "heap" allocated bare (as in not
>> embedded in some other object) list?  Removing it would save ~25 lines of code/comments.
>
> Did a quick skim as well and yes, quite a few ad-hoc lists in the code base. Did not see a case needing this and I think removing this makes sense if we don't see an obvious use-case.

OK, removed.  We can always add it back if we find a use-case.

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PR Review Comment: https://git.openjdk.org/jdk/pull/15896#discussion_r1361772816