[net7.0 / net8.0] [iOS] Memory leak when CollectionView.ItemsSource changes

[Sergtek]

Description

I am aware of the existence of the following bug #13530 but only mention is made of Windows, however in iOS the same memory leak problem also occurs when updating the ItemsSource of a CollectionView several times and the RAM memory is not released even by browsing backwards:

I leave a video playing an example repository where I can reproduce this problem in iOS until the application crashes due to lack of memory:
https://www.youtube.com/watch?v=_UTEGbE4-ug

I leave the repository that I show in the video so you can do the test:
https://github.com/nacompllo/MemoryLeakEverywhere/tree/bugfix/memoryLeakItemsSource

Steps to Reproduce

• Clone the following repository:
  https://github.com/nacompllo/MemoryLeakEverywhere/tree/bugfix/memoryLeakItemsSource
• Run the app on an iOS device.
• Have Xcode Instruments open to see how the RAM increases.
• Follow the same steps as in the attached video.

Link to public reproduction project repository

https://github.com/nacompllo/MemoryLeakEverywhere/tree/bugfix/memoryLeakItemsSource

Version with bug

7.0 (current)

Last version that worked well

Unknown/Other

Affected platforms

iOS

Affected platform versions

iOS 16

Did you find any workaround?

No response

Relevant log output

No response

Depends on

• [ios] fix memory leak in Image #15062
• Formalize virtual layout concepts and fix iOS memory leaks #15303
• [ios] fix memory leak in CollectionView cells #15831
• [ios] fix memory leak in Border #15946

[drasticactions]

How is this different from #14654, which is not closed?

[Sergtek]

How is this different from #14654, which is not closed?

The #14654 is about a memory leak when repeatedly navigating between pages and #14664 is a memory leak when the ItemsSource from CollectionView changes.

[jonathanpeppers]

@nacompllo and you were testing this on .NET 7?

It might be fixed by this one, which is only in main/.NET 8 currently:

• [controls] fix memory leak in CollectionView #14329

I will test your above sample, though, thanks.

[jonathanpeppers]

Note that my comment here:

Is specifically talking about a list of "logical children" that grew indefinitely on Windows.

[jonathanpeppers]

There appears to be an issue with images on iOS, a failing test:

[Fact("Image Does Not Leak")]
public async Task DoesNotLeak()
{
	SetupBuilder();
	WeakReference reference = null;

	await InvokeOnMainThreadAsync(async () =>
	{
		var layout = new VerticalStackLayout();
		var image = new Image
		{
			Background = Colors.Black,
			Source = "red.png",
		};
		layout.Add(image);

		var handler = CreateHandler<LayoutHandler>(layout);
		await image.Wait();
		reference = new WeakReference(image.Handler.PlatformView);
	});

	await Task.Yield();
	GC.Collect();
	GC.WaitForPendingFinalizers();
	
	Assert.NotNull(reference);
	Assert.False(reference.IsAlive, "PlatformView should not be alive!");
}

Still investigating what the fix would be.