Iterator allocations

[eveliotc]

Use of enhanced for loop syntax (e.g. for (SpringListener listener : mListeners) {) causes the creation of unwanted garbage every frame, in example here is a capture of Inertia Ball demo

Would you consider not using it particularly in methods which are called often like advance?

[willbailey]

Yes absolutely we should fix this. Happy to take a pull request or I can fix it up this weekend.

[ghost]

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[mfurtak]

Hi @willbailey - I'm interested in submitting a PR for this change!

How would you feel about substituting CopyOnWriteArrayLists with contains() checks on addition, for the CopyOnWriteArraySets? My initial experiments seem positive.

Before:

After:

[mfurtak]

Upon further thought, all of these Iterators are what are providing the thread-safe iteration guarantees. Any solution that removes those CowIterator allocations will be removing those guarantees (without other arrangements being made).

That leaves me curious - what solution were you imagining?