FIX: GPF on Session Expiration Using Active Server Pages (164495)

The information in this article applies to:

Microsoft Active Server Pages
Microsoft Internet Information Server 4.0

This article was previously published under Q164495

SYMPTOMS

Under certain circumstances, you may see a Genereral Protection Fault (GPF) when a session expires, or when Microsoft Internet Information Server is shut down.

CAUSE

This error is caused by a reference counting problem in Active Server Pages (ASP, which can occur if you attempt store an array containing objects in a Session variable. Consider the code example below:

   dim Arr(1)
   Arr(0) = Server.CreateObject("MyProgID.MyClassId")
   Session("MyVar") = Arr

When the session ends, or is terminated by an Internet Information Server shutdown, the object pointer is released. In addition, VariantClear() is called on the Variant containing the array "Arr". This results in a second attempt to release the object pointer stored in "Arr", and thus a GPF.

RESOLUTION

The best workaround for this problem is to avoid storing arrays of objects in Session variables.

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article.

This bug was corrected in Windows 2000.

MORE INFORMATION

Steps to Reproduce Behavior

The following ASP page may cause the described error to occur when IIS is shut down or the session expires.

PAGE1.ASP

   <HTML>
   <HEAD><TITLE>Document Title</TITLE></HEAD>
   <BODY>
   <%
   Dim MyArray(2)
   Set MyArray(1) = Server.CreateObject("ADODB.Connection")
   Set MyArray(2) = Server.CreateObject("ADODB.Connection")
   Session("SessionAry") = MyArray
   %>
   </BODY>
   </HTML>

REFERENCES

For the latest Knowledge Base articles and other support information on Visual InterDev and Active Server Pages, see the following page on the Microsoft Technical Support site:

http://support.microsoft.com/search/default.aspx?qu=vinterdev

Modification Type:	Major	Last Reviewed:	5/2/2006
Keywords:	kbASPObj kbBug kbfix kbiis500fix kbOSWin2000fix kbWebServer KB164495