panic: GC failed to enter single threaded mode (possibly undetached threads?

panic: GC failed to enter single threaded mode (possibly undetached threads?

Post by tsahi » Sun, 17 Aug 2003 01:08:26


When I work with the Timer class in java and call timer.cancel() to
stop using the timer thread that is created by this class, I get the
message 'panic: GC failed to enter single threaded mode (possibly
undetached threads?' to the console the first time the garbage
collector is called.

Any idea what can I do?

1. User Mode Thread vs Kernel Mode Thread

2. Current thread must be set to single thread apartment (STA)


I have just upgraded a 2003 project to 2005. I get an error when
trying to access a FolderBrowserDialog as follows

Private Sub Button1_Click_2(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles Button1.Click

FolderBrowserDialog1.Description = "Please select a location for
your web pages."

'Default to the c drive if it exists
If Directory.Exists("c:\") = True Then
FolderBrowserDialog1.SelectedPath = "c:\"
FolderBrowserDialog1.SelectedPath = ""
End If


end sub

The error I get is:
"the Current thread must be set to single thread apartment (STA) mode before
OLE calls can be made. Ensure that your Main function has STAThreadAttribute
marked on it. This exception is only raised if a de *** is attached to the

So i created a class 'clsStartup' containing a main procedure:

Public Class clsStartup

<STAThread()> _
Shared Sub Main()

' Declare a variable named frm1 of type Form1.
Dim frm1 As frmWSGWebSiteLocationUpdate

' Instantiate (create) a new Form1 object and assign

' it to variable frm1.

frm1 = New frmWSGWebSiteLocationUpdate()

' Call the Application class' Run method

' passing it the Form1 object created above.


End Sub

End Class

And set the startup object to be clsStartup.

But I still get the same message.

Can anyone help me please?



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