APPC Display Call Fails With AP_STATE_CHECK (Primary_rc = 0002)

ID: Q182265

The information in this article applies to:

Microsoft SNA Server, versions 3.0, 3.0 SP1, 3.0 SP2, 4.0

SYMPTOMS

Occasionally, the APPC DISPLAY function will fail with the following error:

primary_rc = 0x0002 (AP_STATE_CHECK)
secondary_rc = 0x00000000

This problem seems to occur when two separate DISPLAY calls are made at the same time from two different threads of the same APPC program.

CAUSE

Although the APPC DISPLAY function is implemented in a thread-safe manner, it does not properly handle unsolicited status messages received from the SNA Server, which could cause AP_STATE_CHECK to be returned in error. This problem is not related to issuing separate DISPLAY calls from different threads.

STATUS

Microsoft has confirmed this to be a problem in SNA Server 3.0, 3.0 Service Pack 1 (SP1), 3.0 SP2, and 4.0. We are researching this problem in SNA Server version 3.0 and will post new information here in the Microsoft Knowledge Base as it becomes available.

This problem was corrected in the latest SNA Server version 4.0 U.S. Service Pack. For information on obtaining this Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

Additional query words:

Keywords : kbnetwork kbbug4.00 kbfix4.00.sp1 snaappc kbbug3.00 snaprog kbbug3.00.sp2 kbbug3.00.sp1
Version : WINDOWS:3.0,3.0 SP1,3.0 SP2,4.0
Platform : WINDOWS
Issue type : kbbug