Choosing a Threading Model

There are two versions of the XML control.

rental model

The rental model version is designed for single-threaded access. To use the rental model control provided with MSXML 5.0, use the Microsoft.DOMDocument.5.0 progID.

free-threaded model

The free-threaded model version is designed for multiple thread access. To use the free-threaded control provided with MSXML 5.0, use the Microsoft.FreeThreadedDOMDocument.5.0 progID.

Note  In MSXML, "free-threaded" means ThreadingModel='Both', and cross-thread marshalling is supported.

If you plan for several threads to access your XML data from a single control, be sure to use the free-threaded control. If only one thread will access the XML data, use the rental model control for better performance.

The following is a sample global.asa file that creates session-level and application-level free-threaded versions of the XML control.

<SCRIPT LANGUAGE=VBScript RUNAT=Server>
  Sub Session_OnStart
    ON error RESUME next
     
    SET Application("AppFXMLdoc") = _
      server.CreateObject("Msxml2.FreeThreadedDOMDocument.5.0")
    SET Session("SessFXMLdoc") = _
      server.CreateObject("Msxml2.FreeThreadedDOMDocument.5.0")
  End Sub
  Sub Session_OnEnd
    ON error RESUME next
      
    SET Session("SessFXMLdoc") = nothing
    SET Application("AppFXMLdoc") = nothing
    Session("SessFXMLdoc") = empty
    Application("AppFXMLdoc") = empty
  End Sub
</SCRIPT>

Scripts accessing the Session and Application objects will be able to simultaneously access the AppFXMLdoc and SessFXMLdoc objects.