DOCUMENT:Q137246  13-JUN-2001  [sna]
TITLE   :Windows 3.x APPC Application Fails with F002 (AP_TP_BUSY) Error
PRODUCT :Microsoft SNA Server
PROD/VER:WINDOWS:2.0,2.1,2.11
OPER/SYS:
KEYWORDS:

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The information in this article applies to:

 - Microsoft SNA Server, versions 2.0, 2.1, 2.11, on platform(s):
    - the operating system: Microsoft Windows NT 
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SYMPTOMS
========

The Microsoft SNA Server APPC Programmer's Reference documents the following
reason for a primary return code of F002 (AP_TP_BUSY) error:

   F002 AP_TP_BUSY

   The Local TP has issued a call to APPC while APPC was processing another call
   for the same TP. This may occur if the local TP has multiple threads, and
   more than one thread is issuing APPC calls using the same tp_id.

However, this is not the only possible cause of this error when running the
Windows 3.x client. The SNA Server Windows 3.x APPC interface also returns
AP_TP_BUSY (primary return code = F002) to an application if it calls into the
APPC interface from a Windows procedure from SendMessage().

Applications that talk over the CPIC interface may also encounter this problem
because the CPIC API communicates over the APPC API. If this APPC error is
returned to the CPIC interface as a result of a CMINIT call, CPIC returns Error
20 (product specific error) to the application. To see if this error is
occurring, SNA Server Windows 3.x CPIC and APPC API tracing must be enabled. For
additional information, please see the following article(s) in the Microsoft
Knowledge Base:

   Q123256 Enabling SNA Server Windows 3.x Client Traces

Some third party applications require do not run reliably on the SNA Server
Windows 3.x client software unless the TP_BUSY check is disabled. Wall Data
Rumba AS/400 Shared Folders requires that the TP_BUSY check is disabled.

CAUSE
=====

This additional TP_BUSY check is done by the APPC interface to prevent a
possible deadlock within Windows.

RESOLUTION
==========

Using the SNA Server 2.11 Windows 3.x client software, the following parameter
can be set in the [wnap] section of WIN.INI file to disable this SendMessage
check:

   SendMessageCheck=NO

The SNA Server Windows client process (WNAP) must be stopped and started to
enable this change.

WARNING: This parameter should be used with caution, since it can lead to
deadlocks from within Windows, depending on the other Windows applications that
are running on the computer.

STATUS
======

Microsoft has implemented this setting within the SNA Server 2.11 Windows client
software. SNA Server 2.0 and 2.1 customers should upgrade to SNA Server 2.11.


Additional query words: prodsna 2.00 2.10 2.11 tp_busy F002

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Keywords          :  
Technology        : kbAudDeveloper kbSNAServSearch
Version           : WINDOWS:2.0,2.1,2.11
Issue type        : kbbug
Solution Type     : kbfix

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