Windows Form application freeze randomly when run overnight

Question

Hi,

I have a window form application, and it has multiple threads running that would invoke on the Main UI thread to update the UI. Occasionally on development machine, the application main UI thread will stop running, and the application no longer responses. It seems to happen if I left the application running overnight. However, I have users who run this window form application though remote desktop, and this problem happen a lot more often if the application is left running overnight with no user interaction.

I have find an article seems to be describing this problem, but I don't have enough Windows development knowledge to figure out why the application would freeze.

The only information I got is the following stack trace, indicating the main UI thread is waiting for some kind of operation.

This problem has been bothering me for quite some time now. I would appreciate any suggestions or comments.

Thanks!

Main UI thread stack trace:

mscorlib.dll!System.Threading.WaitHandle.WaitOne(long timeout, bool exitContext) + 0x2f bytes
mscorlib.dll!System.Threading.WaitHandle.WaitOne(int millisecondsTimeout, bool exitContext) + 0x25 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.WaitForWaitHandle(System.Threading.WaitHandle waitHandle = {System.Threading.ManualResetEvent}) Line 4268 C#
System.Windows.Forms.dll!System.Windows.Forms.Control.MarshaledInvoke(System.Windows.Forms.Control caller, System.Delegate method, object[] args, bool synchronous) Line 7614 C#
System.Windows.Forms.dll!System.Windows.Forms.Control.Invoke(System.Delegate method, object[] args) Line 7178 + 0x11 bytes C#
System.Windows.Forms.dll!System.Windows.Forms.WindowsFormsSynchronizationContext.Send(System.Threading.SendOrPostCallback d, object state) Line 89 C#
System.dll!Microsoft.Win32.SystemEvents.SystemEventInvokeInfo.Invoke(bool checkFinalization = true, object[] args = {object[2]}) + 0x62 bytes
System.dll!Microsoft.Win32.SystemEvents.RaiseEvent(bool checkFinalization = true, object key = {object}, object[] args = {object[2]}) + 0x10f bytes
System.dll!Microsoft.Win32.SystemEvents.OnUserPreferenceChanging(int msg, System.IntPtr wParam, System.IntPtr lParam) + 0x77 bytes
System.dll!Microsoft.Win32.SystemEvents.WindowProc(System.IntPtr hWnd = 2032836, int msg = 8218, System.IntPtr wParam = 47, System.IntPtr lParam = 100019840) + 0x2ca bytes
[Native to Managed Transition]
[Managed to Native Transition]
System.Windows.Forms.dll!System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(int dwComponentID, int reason = 4, int pvLoopData = 0) Line 2106 + 0x8 bytes C#
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(int reason = 4, System.Windows.Forms.ApplicationContext context = {System.Windows.Forms.Application.ModalApplicationContext}) Line 3377 + 0x1b bytes C#
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(int reason, System.Windows.Forms.ApplicationContext context) Line 3261 + 0xa bytes C#
System.Windows.Forms.dll!System.Windows.Forms.Application.RunDialog(System.Windows.Forms.Form form) Line 1488 C#
System.Windows.Forms.dll!System.Windows.Forms.Form.ShowDialog(System.Windows.Forms.IWin32Window owner) Line 6120 + 0x8 bytes C#
Schedule.exe!ME.APTS.ScheduleApp.ScheduleAppMainForm.ShowOpenScheduleForm.AnonymousMethod() Line 829 + 0xd bytes C#
Schedule.exe!ME.APTS.ScheduleApp.ScheduleAppMainForm.PromptUserToSaveSchedule(System.Action oAfterPromptUserToSaveCallBack = {Method = Cannot evaluate expression because the code of the current method is optimized.}) Line 1858 + 0xb bytes C#
Schedule.exe!ME.APTS.ScheduleApp.ScheduleAppMainForm.ShowOpenScheduleForm() Line 859 + 0xb bytes C#
[Native to Managed Transition]
[Managed to Native Transition]
mscorlib.dll!System.Delegate.DynamicInvokeImpl(object[] args) + 0x55 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackDo(System.Windows.Forms.Control.ThreadMethodEntry tme) Line 7266 + 0xb bytes C#
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbackHelper(object obj) Line 7228 + 0x7 bytes C#
mscorlib.dll!System.Threading.ExecutionContext.runTryCode(object userData) + 0x51 bytes
[Native to Managed Transition]
[Managed to Native Transition]
mscorlib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x67 bytes
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x45 bytes
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallback(System.Windows.Forms.Control.ThreadMethodEntry tme) Line 7213 + 0xffffffc5 bytes C#
System.Windows.Forms.dll!System.Windows.Forms.Control.InvokeMarshaledCallbacks() Line 7297 + 0xb bytes C#
System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) Line 13848 C#
System.Windows.Forms.dll!System.Windows.Forms.ScrollableControl.WndProc(ref System.Windows.Forms.Message m) Line 1491 C#
System.Windows.Forms.dll!System.Windows.Forms.ContainerControl.WndProc(ref System.Windows.Forms.Message m) Line 1898 C#
System.Windows.Forms.dll!System.Windows.Forms.Form.WndProc(ref System.Windows.Forms.Message m) Line 7515 C#
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) Line 14051 C#
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) Line 14106 C#
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg = 49512, System.IntPtr wparam, System.IntPtr lparam) Line 647 + 0xa bytes C#
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.DefWndProc(ref System.Windows.Forms.Message m = {System.Windows.Forms.Message}) Line 814 + 0x1d bytes C#
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.WndProc(ref System.Windows.Forms.Message m) Line 1409 C#
Infragistics2.Win.UltraWinToolbars.v8.1.dll!Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.FormSubClasser.WndProcImpl(ref System.Windows.Forms.Message m) + 0x17f5 bytes
Infragistics2.Win.UltraWinToolbars.v8.1.dll!Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.FormSubClasser.WndProc(ref System.Windows.Forms.Message m) + 0x5 bytes
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg = 49512, System.IntPtr wparam, System.IntPtr lparam) Line 647 + 0xa bytes C#
[Native to Managed Transition]
[Managed to Native Transition]
System.Windows.Forms.dll!System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(int dwComponentID, int reason = -1, int pvLoopData = 0) Line 2106 + 0x8 bytes C#
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(int reason = -1, System.Windows.Forms.ApplicationContext context = {System.Windows.Forms.ApplicationContext}) Line 3377 + 0x1b bytes C#
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(int reason, System.Windows.Forms.ApplicationContext context) Line 3261 + 0xa bytes C#
System.Windows.Forms.dll!System.Windows.Forms.Application.Run() Line 1457 C#
Schedule.exe!ME.APTS.ScheduleApp.ScheduleApp.LoadData() Line 318 + 0x5 bytes C#
Schedule.exe!ME.APTS.ScheduleApp.ScheduleApp.Run() Line 170 + 0x9 bytes C#
Schedule.exe!ME.APTS.ScheduleApp.ScheduleApp.Main() Line 126 + 0xb bytes C#

Answer 1

I experienced this exact same issue about a year ago (application hang after some time without user interaction, with OnUserPreferenceChanging() in the call stack).

The most likely cause is that you're using InvokeRequired/Invoke() on a control and not on the main form. This sometimes produces the wrong result if the control's handle hasn't been created yet.

The solution is to always call InvokeRequired/Invoke() on the Main Window (which you can cast as an ISynchronizeInvoke if you don't want to introduce a dependency to your form class).

You can find an excellent, very detailed description of the cause and solution here.

Answer 2

Yes, this is a fairly infamous threading problem caused by the SystemEvents class. I never got a solid diagnostic for it but I'm 90% sure that this is an initialization problem in your app.

The root problem is that SystemEvents gets initialized on-demand by the first form in your app that has controls that are interested in the events it generates. If that first form is not created in the main thread then SystemEvents creates its hidden notification window on the wrong thread. Eventually, when a notification is received (like UserPreferenceChanging), you'll get a deadlock.

Review the startup sequence of your app. Creating your own splash screen instead of using the one built in .NET is a good lead. Any place where you might create your own form on a worker thread is a red flag too. This can be unintentional if you use VB.NET