Memory leak with ProgressBar when IsIndeterminate="True"

[ihtfw]

Describe the bug

In my application, I encountered a memory leak and, after long debugging, found that if the progress bar has the Intermediate="True" flag, the resources are not released when the window is closed.
I've created the project where this can be reproduced.

https://github.com/ihtfw/AvaloniaProgressBarMemoryLeakDemo

To Reproduce

• Clone project repo https://github.com/ihtfw/AvaloniaProgressBarMemoryLeakDemo
• Run project ProgressBarMemoryLeakDemo.Desktop
• Attach memory profiler. I've used dotMemory
• Create memory snapshot
• Click Run Test button in application
• Wait until it finished
• Create one more memory snapshot
• Compare snapshots
• Now we see that 5 ProgressWindow objects are kept, but they should not!

If I change IsIndeterminate to False in ProgressWindow.axaml then everything works as expected.

Expected behavior

Release ProgressWindow object on close

Avalonia version

11.1.2

OS

Windows

Additional context

If we check Key retention paths, then it looks like that IsIndeterminate animation is causing problems. In my application I've make temporary fix this problem by changing IsIndeterminate to false in window close event. It solves the problem, but it's definitely incorrect behaviour.

[danipen]

I used this workaround:

        class ProgressBarWithMemoryLeakWorkaround : ProgressBar
        {
            protected override Type StyleKeyOverride => typeof(ProgressBar);

            protected override void OnPropertyChanged(AvaloniaPropertyChangedEventArgs change)
            {
                base.OnPropertyChanged(change);

                // Workaround for a memory leak in indeterminate progress bars:
                // When a progress bar is set to indeterminate, the Avalonia Compositor
                // leaks the animation, which in turn leaks all controls that reference
                // the progress bar. This workaround removes the indeterminate pseudo-class
                // whenever the progress bar becomes not visible.

                if (change.Property == IsIndeterminateProperty ||
                    change.Property == IsVisibleProperty)
                {
                    PseudoClasses.Set(":indeterminate", IsVisible && IsIndeterminate);
                }
            }
        }

It requires hiding every visible progress bar before disposing the view containing it.

[ihtfw]

As a temporary workaround, I set IsIndeterminate to false within the Unload event. Ideally, this should be resolved within Avalonia itself to eliminate the need for such workarounds.

[vanka78bg]

This affects us too. Applying that workaround for each ProgressBar with IsIndeterminate set to true is tedious. I believe this is somehow related to the Animation object with infinite looping animations. Please, raise the priority of this bug.

[timunie]

Hi @vanka78bg in case you have a support agreement, you can ask for priority on issues.

[aguahombre]

Adding this to ProgressBar.cs in addition to @danipen suggestion above fixed the memory leak for me

        protected override void OnDetachedFromVisualTree(VisualTreeAttachmentEventArgs e)
        {
            // stop the animation - otherwise there is a memory leak; see #16648
            PseudoClasses.Set(":indeterminate", false);
            base.OnDetachedFromVisualTree(e);
        }

I didn't need any workarounds in my code.
I suspect this is just hiding the real issue which is to do with animations.

[DrDryg]

I have the same memory leak in avalonia 12.