DOCUMENT:Q247319 11-DEC-1999 [foxpro]
TITLE :PRB: PUBLIC Variables Not Released from InProcess Servers in ASP
PRODUCT :Microsoft FoxPro
PROD/VER:WINDOWS:6.0
OPER/SYS:
KEYWORDS:kbAutomation kbInternet kbvfp600 kbGrpDSFox kbDSupport
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The information in this article applies to:
- Microsoft Visual FoxPro for Windows, version 6.0
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SYMPTOMS
========
Public variables declared in an in-process Microsoft Visual FoxPro OLE
Automation Server, launched from an ASP page, are not released when the OLE
Automation Server is released.
CAUSE
=====
PUBLIC variables declared within an in-process OLE Automation Server are public
to the thread and any object on the thread. PUBLIC variables are not released
until the thread has been uninitialized and the client has unloaded the
in-process server. Setting the instance of the in-process server object to
"nothing" does not unload the server.
RESOLUTION
==========
Set the scope of variables used within in-process OLE Automation Servers, used
with Active Server Pages, to PRIVATE rather than PUBLIC.
STATUS
======
This behavior is by design.
MORE INFORMATION
================
Steps to Reproduce Behavior
---------------------------
1. Create a new project named MTHREAD.
2. Add a new program file to the project, using the following code:
DEFINE CLASS mthread AS CUSTOM OLEPUBLIC
FUNCTION PublicHit
LPARAMETER lnSecs
LOCAL x
lnSecs=IIF(EMPTY(lnSecs),0,lnSecs)
IF lnSecs > 60
lnSecs = 61
ENDIF
IF VARTYPE(gnPubValue) = "N"
gnPubValue = gnPubValue + 1
ELSE
PUBLIC gnPubValue
gnPubValue = 1
ENDIF
IF VARTYPE(gnPrivValue) = "N"
gnPrivValue = gnPrivValue + 1
ELSE
PRIVATE gnPrivValue
gnPrivValue = 1
ENDIF
DECLARE Sleep IN WIN32API INTEGER
FOR x=1 TO lnSecs
FOR x=1 TO lnSecs
Sleep(1000)
ENDFOR
ENDFOR
DECLARE INTEGER GetCurrentThreadId IN WIN32API
lcHTML = [
] + CHR(13) + ;
[] + ;
"The request completed in " + TRANS(lnSecs) + " seconds." + [ |
] +CHR(13) +;
[] + CHR(13) + ;
"The current Thread ID is: " + TRANS(GetCurrentThreadId()) + ""+CHR(13) + ;
"The Public Value (gnPubValue) : = " + TRANS(gnPubValue) + "
"+ CHR(13) + ;
"The Private Value (gnPrivValue): = " + TRANS(gnPrivValue) + "
"
RETURN lcHTML
ENDFUNC
ENDDEFINE
3. Click the Build button on the Project Manager, and select either a
Single-threaded COM server (dll) or a Multi-threaded COM server (dll).
4. Install the COM Server and run-time files on a computer running Internet
Information Server.
5. Register the COM Server.
6. Create an Active Server Page named TEST.ASP in the IIS WWWROOT directory
using the following code, and make certain that the directory has execute
privileges:
<%@ Language=VBScript %>
<%
Set oVFPApp = Server.CreateObject("mthread.mthread")
Response.Write oVFPApp.PublicHit
set oVFPApp = nothing
%>
7. Launch your Web Browser and navigate to the Active Server Page that was
created in step 4. Refresh the page several times, and note that the value of
gnPubValue is incremented each time the page is refreshed.
8. Close your Web Browser.
9. Launch your Web Browser and navigate to the Active Server Page that was
created in step 4. Note that the value of gnPubValue is not 1.
REFERENCES
==========
Q156547 HOWTO: Manually Register a Custom OLE Server
Q156014 HOWTO: Set Up OLE Automation in Visual FoxPro
Additional query words:
======================================================================
Keywords : kbAutomation kbInternet kbvfp600 kbGrpDSFox kbDSupport
Technology : kbVFPsearch kbAudDeveloper kbVFP600
Version : WINDOWS:6.0
Issue type : kbprb
=============================================================================
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