[Windows] Window Memory Leak

[danielancines]

Description

I'm working for a big company and we having memory leaks issues, when user opens a new window, the memory on Task Manager never is released and still increasing. To test purposes, I created a fresh new Maui .net 8 app and got some weird behaviors.

After open 5 windows and closing them, opening more 9 windows and closing them, it appears that old 5 windows come back to life and still on the heap. Other issue is, the memory on task manager never is released and still increasing with more windows creation. Sometimes the old windows come back to life to and the number os Controls.Window are increased on the next snapshot.

Steps to Reproduce

1. Create new .dotnet 8 Maui app.
2. The steps to reproduce are described above.

Link to public reproduction project repository

https://github.com/danielancines/memory-leak-dotnet8-maui

Version with bug

8.0.3 GA

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

Unknown/Other

Affected platforms

Windows

Affected platform versions

No response

Did you find any workaround?

No

Relevant log output

No response

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[rodirigos]

Still having similar problems in dotnet8. Can you please provide a fix for this problem? I'm cleaning all the events and even a empty window can cause this after a while.

[RoiChen001]

Can repro this issue at Windows platform on the latest 17.11.0 Preview 2.0(8.0.0-rc.2.9530&8.0.40).

[danielancines]

Hi guys, I'm running a lot of tests on Maui repo and the reasons for Window memory leak appears in a lot of places

Myview is a custom ContentView that stay on memory after window close. I found an event that never unassigned on VisualDiagnosticsOverlay

Still looking for a workaround, because this problem still crashing my app because memory still increasing after hours of working.

[danielancines]

I've been running some tests with WinUI3 and apparently has the same problem, the memory still increasing and never released.

[lfmouradasilva]

I have the same problem in my project that has already been launched in production. Does anyone have a workaround?

[fpedrolucas95]

I have the same problem in my project, and this issue is crucial for us.

[ImLusca]

Got the same issue in my project. Do we already have a workaround?

[rodirigos]

Any update on this problem?

[MasterOliver21]

Unfortunately, I am having the same problem and can't find a solution. Any feedback?

[MartyIX]

I've been running some tests with WinUI3 and apparently has the same problem, the memory still increasing and never released.

Then it's certainly a good idea to report it in the https://github.com/microsoft/microsoft-ui-xaml repo.

[danielancines]

I identify on WindowHandler.Windows.cs class that MauiWinUIWindow still on windowRootContentManager (NavigationRootManager) at _platformWindow field, after clear it using reflection, MauiWinUIWindow instances was collected by GC.

---

Controls.Window still in memory, searching for an workaround to release them

---

My content view still on memory too

It appears that dotnet Maui has a lot of Memory Leak points, RAM memory never release.

[danielancines]

Cleaning GestureManager from MyView (ContentView) on unload, it was possbile to release some memory and remove all MauiWinUIWindow, Window and my content views instances from memory.

Apparently GestureManager and GesturePlatformManager never been disposed and hold an instance of my view after window closed and view unloaded.

[MartyIX]

(Perhaps @jonathanpeppers could comment on this one.)

[jonathanpeppers]

I tested the sample, and made the change:

public class MyContentPage : ContentPage
{
	protected override void OnDisappearing()
	{
		base.OnDisappearing();

		GC.Collect();
	}
}

This will just make the GC more deterministic, so the GC runs as you close each Window. (This is just for debugging, remove it from your app when finished testing)

I also subclassed Window, so I could search for it in .gcdump files more easily:

public class FooWindow : Window
{
    public FooWindow() : base (new MyContentPage()) { }
}

Opening many windows, I only see 1 FooWindow alive at a time in a given snapshot:

I think it just takes a couple GCs for each Window to go away. I don't think I see a leak here?

I would also verify you have XAML hot reload turned off when testing this, see:

• https://aka.ms/maui-memory-leaks

[danielancines]

Hi @jonathanpeppers, thank you for answer me, I made the same code as you, only difference is I run GC.Collect on MainWindow Deactivated and after open new windows, close them, open again I got this result, running in Release:

There's 18 mauiwinuiwindow in memory

Actually FooWindows was collected in my tests, but the main problem is, the use of RAM memory still increasing, and this is the problem in my company's application, check this out:

App running:

Some windows opened:

Some GC.Collect executions:

More windows:

After close them:

My views has only some labels on it, IMHO, since MauiWinUIWindow still in memory, and task manager doesn't show significant memory decrease, something is not right.

Update:
After a couple of minutes with my app running, and GC executions, memory stil the same on task namager:

This is the main problem, if user still opening and closing windows, with more complex views, the memory can reach 1gb with only main window running.

[jonathanpeppers]

Ok, maybe there is a problem with MauiWinUIWindow:

Let me investigate some more, thanks!

[danielancines]

Cleaning GestureManager from MyView (ContentView) on unload, it was possbile to release some memory and remove all MauiWinUIWindow, Window and my content views instances from memory.

Apparently GestureManager and GesturePlatformManager never been disposed and hold an instance of my view after window closed and view unloaded.

Maybe above there's some insights to help your investigation.