RFR: 8184166: SortedList does not free up memory [v4]

[Cormac Redmond]

On Thu, 18 Dec 2025 00:11:32 GMT, Cormac Redmond <duke at openjdk.org> wrote:

>> The problem with the current change is we are wasting time/CPU always, instead of doing only what's strictly needed.  Just imagine if the `sorted` array is fairly large and contains only a few items - then you are overwriting many `null` entries with `nulls` needlessly.
>> 
>> Besides, we have the exact number of entries to null out (`c.getRemovedSize()`), which makes the life easier.
>
> I must be missing something. I don't see how that situation can occur, if sorted is large but only contains a few items, then the source list must have been large at one point, and shrunk, at which point the excess would be nulled, once.
> 
> There's a break there to stop subsequent calls from needlessly nulling anything out on subsequent changes.
> 
> On the other hand, putting inside the if statement means we're needlessly removing elements if they're just about to be overwritten from other changes in the same change set.

Anyway, that's moved inside now, and simplified a bit (there's no need for the null check + break any more).

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PR Review Comment: https://git.openjdk.org/jfx/pull/2000#discussion_r2629045895