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TextBox.Text Memory leak in a WPF application

I have an application that processes a large number of numbers in an array of numbers. I set the status of these numbers for each 100,000 operations. This is just a visual indicator for the operator that the application is still processing, and how complete it is.

After starting the application for several hours, it crashes using OutOfMemoryExeption. I ran CLRProfiler and found that a leak occurs in a TextBox that shows the current state of the array ... the application creates ~ 4K in Char [] every time the interface is updated, the stack trace for each bit of oversized memory is the same.

Is this a bug in WPF, or is there something that I don’t know what should I do to prevent this from happening? I have not seen any other references to this. Since this is a very intensive processor operation, I would prefer not to destroy or rebuild the TextBox unless I just need to display the current state of the array.

This is the only memory leak that I can find, but due to the large number of required operations, this is really a big problem for the application, even if I just reduce the refresh rate of the interface. If you need more information, I will help, if at all possible, but please understand that because of what this application does, I can’t publish almost any source code and I will need to anonymize something (by deleting any indication of the purpose of the application) that I can send.

When launched through the CLR Profiler, which DRASTICALLY reduces performance, the next identical trace occurs every 2 seconds (remember: 100,000 operations), and memory is never freed. When it works without a profiler, the time between updates is <1 second.

Trace from one update ("Who is highlighted"):

<root> :  3.7 kB    (100.00%)
 WpfApplication0.App::Main static void ():  3.7 kB    (100.00%)
  System.Windows.Application::Run int32 ():  3.7 kB    (100.00%)
   System.Windows.Application::Run int32 (System.Windows.Window):  3.7 kB    (100.00%)
    System.Windows.Application::RunInternal int32 (System.Windows.Window):  3.7 kB    (100.00%)
     System.Windows.Application::RunDispatcher Object (Object):  3.7 kB    (100.00%)
      System.Windows.Threading.Dispatcher::Run static void ():  3.7 kB    (100.00%)
       System.Windows.Threading.Dispatcher::PushFrame static void (System.Windows.Threading.DispatcherFrame):  3.7 kB    (100.00%)
        System.Windows.Threading.Dispatcher::PushFrameImpl void (System.Windows.Threading.DispatcherFrame):  3.7 kB    (100.00%)
         NATIVE FUNCTION ( UNKNOWN ARGUMENTS ):  3.7 kB    (100.00%)
          MS.Win32.HwndSubclass::SubclassWndProc int_ptr (int_ptr int32 int_ptr int_ptr):  3.7 kB    (100.00%)
           System.Windows.Threading.Dispatcher::Invoke Object (System.Windows.Threading.DispatcherPriority  Object):  3.7 kB    (100.00%)
            System.Windows.Threading.Dispatcher::InvokeImpl Object (System.Windows.Threading.DispatcherPriority   Object bool):  3.7 kB    (100.00%)
             System.Windows.Threading.Dispatcher::WrappedInvoke Object ( Object bool ):  3.7 kB    (100.00%)
              System.Windows.Threading.ExceptionWrapper::TryCatchWhen Object (Object  Object bool ):  3.7 kB    (100.00%)
               System.Windows.Threading.ExceptionWrapper::InternalRealCall Object ( Object bool):  3.7 kB    (100.00%)
                MS.Win32.HwndSubclass::DispatcherCallbackOperation Object (Object):  3.7 kB    (100.00%)
                 MS.Win32.HwndWrapper::WndProc int_ptr (int_ptr int32 int_ptr int_ptr bool&):  3.7 kB    (100.00%)
                  System.Windows.Threading.Dispatcher::WndProcHook int_ptr (int_ptr int32 int_ptr int_ptr bool&):  3.7 kB    (100.00%)
                   System.Windows.Threading.Dispatcher::ProcessQueue void ():  3.7 kB    (100.00%)
                    System.Windows.Threading.DispatcherOperation::Invoke Object ():  3.7 kB    (100.00%)
                     System.Threading.ExecutionContext::Run static void (System.Threading.ExecutionContext System.Threading.ContextCallback Object):  3.7 kB    (100.00%)
                      System.Threading.ExecutionContext::RunInternal static void (System.Threading.ExecutionContext System.Threading.ContextCallback Object):  3.7 kB    (100.00%)
                       System.Threading.ExecutionContext::runTryCode static void (Object):  3.7 kB    (100.00%)
                        System.Windows.Threading.DispatcherOperation::InvokeInSecurityContext static void (Object):  3.7 kB    (100.00%)
                         System.Windows.Threading.DispatcherOperation::InvokeImpl void ():  3.7 kB    (100.00%)
                          System.Windows.Threading.Dispatcher::WrappedInvoke(1) Object ( Object bool ):  3.7 kB    (100.00%)
                           System.Windows.Threading.ExceptionWrapper::TryCatchWhen(1) Object (Object  Object bool ):  3.7 kB    (100.00%)
                            System.Windows.Threading.ExceptionWrapper::InternalRealCall(1) Object ( Object bool):  3.7 kB    (100.00%)
                             System.Delegate::DynamicInvokeImpl Object (Object[]):  3.7 kB    (100.00%)
                              System.Reflection.RuntimeMethodInfo::Invoke Object (Object System.Reflection.BindingFlags System.Reflection.Binder Object[] System.Globalization.CultureInfo bool):  3.7 kB    (100.00%)
                               System.RuntimeMethodHandle::InvokeMethodFast Object (Object Object[] System.Signature System.Reflection.MethodAttributes System.RuntimeTypeHandle):  3.7 kB    (100.00%)
                                WpfApplication0.Window1::UpdateUI void ():  3.7 kB    (100.00%)
                                 System.Windows.Controls.TextBox::set_Text void (String):  3.7 kB    (100.00%)
                                  System.Windows.DependencyObject::SetValue void (System.Windows.DependencyProperty Object):  3.7 kB    (100.00%)
                                   System.Windows.DependencyObject::SetValueCommon void (System.Windows.DependencyProperty Object System.Windows.PropertyMetadata bool System.Windows.OperationType bool):  3.7 kB    (100.00%)
                                    System.Windows.DependencyObject::UpdateEffectiveValue System.Windows.UpdateResult (System.Windows.EntryIndex System.Windows.DependencyProperty System.Windows.PropertyMetadata System.Windows.EffectiveValueEntry System.Windows.EffectiveValueEntry& bool System.Windows.OperationType):  3.7 kB    (100.00%)
                                     System.Windows.DependencyObject::NotifyPropertyChange void (System.Windows.DependencyPropertyChangedEventArgs):  3.7 kB    (100.00%)
                                      System.Windows.Controls.TextBox::OnPropertyChanged void ():  3.7 kB    (100.00%)
                                       System.Windows.FrameworkElement::OnPropertyChanged void ():  3.7 kB    (100.00%)
                                        System.Windows.DependencyObject::OnPropertyChanged void (System.Windows.DependencyPropertyChangedEventArgs):  3.7 kB    (100.00%)
                                         System.Windows.Controls.TextBox::OnTextPropertyChanged static void ( ):  3.7 kB    (100.00%)
                                          System.Windows.Documents.TextContainer::DeleteContentInternal void (System.Windows.Documents.TextPointer System.Windows.Documents.TextPointer):  3.7 kB    (100.00%)
                                           System.Windows.Documents.TextTreeUndo::CreateDeleteContentUndoUnit static System.Windows.Documents.TextTreeDeleteContentUndoUnit (System.Windows.Documents.TextContainer System.Windows.Documents.TextPointer System.Windows.Documents.TextPointer):  3.7 kB    (100.00%)
                                            System.Windows.Documents.TextTreeDeleteContentUndoUnit::.ctor void (System.Windows.Documents.TextContainer System.Windows.Documents.TextPointer System.Windows.Documents.TextPointer):  3.7 kB    (100.00%)
                                             System.Windows.Documents.TextTreeDeleteContentUndoUnit::CopyContent ContentContainer (System.Windows.Documents.TextTreeNode System.Windows.Documents.TextTreeNode):  3.7 kB    (100.00%)
                                              System.Windows.Documents.TextTreeDeleteContentUndoUnit::CopyTextNode System.Windows.Documents.TextTreeNode (System.Windows.Documents.TextTreeTextNode System.Windows.Documents.TextTreeNode ContentContainer&):  3.7 kB    (100.00%)
                                               System.Char [] :  3.7 kB    (100.00%)

and code generating the user interface update:

        List<int> arraystatus = new List<int>(displayarray.ToArray());

        StringBuilder s = new StringBuilder();

        int i = 1;

        foreach (int item in arraystatus)
        {
            s.Append(i.ToString() + ":\t" + item.ToString() + (i % 8 == 0 ? "\n" : "\t"));
            i++;
        }

        txtStatus.Text = s.ToString();

        arraystatus = null;
        s = null;
+3
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2 answers

From the documentation for the TextBoxBase.UndoLimit property:

The number of actions stored in the cancel queue. The default value is -1, which means that the undo queue is limited by available memory.

You have found this limit. Set it to a sufficiently small value.

. . , TextBlock - .

UPDATE: .NET 4.5 -1 100, .

+17

+1 .

, StringBuilder. .

arraystatus ( 100k , ) , , StringBuilder .

s.Append(i.ToString());
s.Append(":\t");
s.Append(item.ToString());
s.Append(i % 8 == 0 ? "\n" : "\t"));

, , AppendFormat.

+2

Source: https://habr.com/ru/post/1756598/

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