Windows 3.x APPC Application Fails with F002 (AP_TP_BUSY) Error

Last reviewed: April 24, 1996
Article ID: Q137246

The information in this article applies to:

Microsoft SNA Server for Windows NT, versions 2.0, 2.1, and 2.11

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:

   ARTICLE-ID: Q123256
   TITLE     : 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.

KBCategory: kbnetwork kbprg kb3rdparty kbbug2.00 kbbug2.10 kbbug2.11
KBSubcategory: ntnetserv
Additional reference words: prodsna 2.00 2.10 2.11 tp_busy F002

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Last reviewed: April 24, 1996
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.