RFR: JDK-8199216: Quadratic layout time with nested nodes and pseudo-class in style sheet [v8]

[John Hendrikx]

On Tue, 15 Aug 2023 14:35:33 GMT, Jose Pereda <jpereda at openjdk.org> wrote:

>> It's definitely a bug, but it would only appear if you had bit sets which required more than 1 long to store their data **and** you called `toArray`.  It would then throw an `ArrayIndexOutOfBoundsException` in this line:
>> 
>>     final long state = getBits()[index];
>> 
>> This is because `index` is used for two unrelated purposes:
>> - the index into the array of longs
>> - the index of the entry in the resulting array
>> 
>> If the outer loop ever needs two passes, it again wants to read a `long` using `getBits()[index]` but as `index` was advanced (multiple times) while filling entries in the result array, it won't be the correct index at all.
>> 
>> Anyway, I'm not sure what the value would be of a test.  Since `toArray` is no longer implemented by us but by `AbstractSet`, I'd just be testing the `AbstractSet` code.
>
> Okay, thanks for the clarification. 
> 
> So if I get it right, the removal of `toArray` doesn't have to do with the bug, but with the fact that with the immutable set it is not longer required?

I removed it because my fix requires that `toArray` works correctly.  The easiest way to get a correctly working version is to extend `AbstractSet`, which provides a default implementation that works correctly.  As I think the default implementation is good enough and performs well enough, I saw no reason to fix the broken version.

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PR Review Comment: https://git.openjdk.org/jfx/pull/1076#discussion_r1295021835