Ayende @ Rahien

Paulo Quicoli commented on Reproducing a WPF memory leak

Thu, 19 Nov 2009 18:19:15 GMT

@jdu, did you download my code? See, in my version, implementing INotifyPropertyChanged resolved memory leak...

jdu commented on Reproducing a WPF memory leak

Thu, 19 Nov 2009 10:18:41 GMT

This looks _really_ bad to me. I think you should open a ticket about it at connect.microsoft.com. Because from my understanding of your case, it would mean almost any binding is leaking. As someone wrote, there's a KB article describing a very similar leak here: [http://support.microsoft.com/kb/938416](http://support.microsoft.com/kb/938416). But in this KB there's an additional condition: the databinding source object X must hold a reference to the target of the binding. Which you don't have. Your repro seems to imply that: Binding to a plain CLR object (no DependencyProperty and no INotifyPropertyChanged) without specifying Mode=OneTime always creates a memory leak. And there are tons of those in every WPF app...

Justin Chase commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 20:19:52 GMT

Mode=OneTime or Mode=OneWay On those bindings.

J commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 17:54:57 GMT

@Eyston Between cross browser css hacks, javascript which behaves differently among different browsers and even browser versions, having to support every platform under the sun only to have to rebase your code every time a new version of a browser comes out... boy I'm glad I develop desktop applications. :) Also, BTW, WPF is the newest UI technology...Winforms (AFAIK) is much more stable since its approaching a decade in maturity

Andrew commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 17:11:59 GMT

I haven't looked at Paulo's solution, so if his works, that's great. In the last blog posting about this issue I believe I posted a "hackish" solution to the problem that should solve your problem. It involves calling the GC and collapsing the process memory. I'm in no way saying it's an ideal solution, but works in a pinch if everything else fails.

Graham Nash commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 17:10:14 GMT

Does anyone have an easy way of doing such a clean memory dump in WinXP? I tried using Debugging Tools for Windows, but WinDbg keeps complaining I am missing symbols. (I followed the installation instructions on MSDN).

Eyston commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 14:55:44 GMT

Reading posts / comments like this make me glad I'm not developing desktop applications. There are just some things you can appreciate people knowing, that you have no desire to know yourself. This kind of non-portable knowledge being one such case :)

Paulo Quicoli commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 11:02:23 GMT

Ayende, as you can see in my code i changed you DataContext object to: public class MyModel: INotifyPropertyChanged { private string runningTime; public string RunningTime { get { return runningTime; } set { runningTime = value; OnPropertyChanged("RunningTime"); } } private string memUsed; public string MemUsed { get { return memUsed; } set { memUsed = value; OnPropertyChanged(MemUsed); } } public void UpdateData() { RunningTime = DateTime.Now.ToString(); MemUsed = GC.GetTotalMemory(true).ToString("#,#"); } public event PropertyChangedEventHandler PropertyChanged; protected void OnPropertyChanged(string name) { PropertyChangedEventHandler handler = PropertyChanged; if (handler != null) { handler(this, new PropertyChangedEventArgs(name)); } } } And in WPF Window, i chaged to: If you run, you will see memory is not getting high by time pass... Memory leak is gone :) (sorry for my bad english)

Rafal commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 10:52:47 GMT

What the hell is MS.Utility.FrugalObjectList?

Paulo Quicoli commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 10:06:56 GMT

Hi Ayende, i solved Memory Leak, take a look please: [cid-b27ccfaa07b93be8.skydrive.live.com/.../....rar](http://cid-b27ccfaa07b93be8.skydrive.live.com/self.aspx/Public/memory%20leak%20solved.rar)

Michael Sync commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 09:24:34 GMT

Hi Szymon, Please correct me if I I tried changing like this below but it still keep increasing. 1. > 2. public class MainViewModel : ViewModelBase { public MainViewModel() { Statistics = new ObservableCollection

grega_g commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 09:20:13 GMT

Here is kb article that i think describes your situation: [http://support.microsoft.com/kb/938416/en-us](http://support.microsoft.com/kb/938416/en-us)

Szymon commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 09:16:41 GMT

Hi Ayende, The problem here is that you use a TwoWay binding to an object that doesn't provide change notification. This forces WPF to use other methods to synchronize the values. There are two solutions: 1) In your bindings use Mode=OneWay. Since you are recreating the items in each iteration you need to read the value only once. 2) Instead of DictionaryEntry use a custom class that implements INotifyPropertyChange interface. This way WPF is able to track changes to property values easily.

Michael Sync commented on Reproducing a WPF memory leak

Tue, 17 Nov 2009 09:12:36 GMT

I think Clear (istics.Clear();) may take a while to clean maybe. we can re-initialize Statistics public void UpdateData() { Statistics = new ObservableCollection