CMWAIT Returns Incorrectly After Canceling CMALLC

The information in this article applies to:

• Microsoft SNA Server, versions 2.11, 2.11 Service Pack 1 (SP1), 2.11 Service Pack 2 (SP2), 3.0, and 3.0 Service Pack 1 (SP1)

SYMPTOMS

When you use the SNA Server Win32 asynchronous CPIC interface, a CPIC application may encounter problems when you cancell an Allocate (CMALLC) call with Cancel_Conversation (CMCANC).

After you cancel a CMALLC using CMCANC, subsequent attempts to issue CMALLC in non-blocking mode appear to show that CMWAIT returns immediately, without waiting for the CMALLC async final completion.

CAUSE

Canceling an asynchronous CPI-C call (not ones that would complete by posting a Windows message) does not work correctly. Later CMWAITs return early because they pick up false completions from the cancelled calls.

STATUS

Microsoft has confirmed this to be a problem in SNA Server versions 2.11, 2.11 Service Pack 1 (SP1), 2.11 Service Pack 2 (SP2), 3.0, and 3.0 Service Pack 1 (SP1).

This problem was corrected in the latest SNA Server version 3.0 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

MORE INFORMATION

The following sequence was observed in an SNA Application CPIC API trace:

   CMINIT ->
      <- CMINIT OK
   CMSPM (set non-blocking mode)
      <- CMSPM OK
   CMALLC ->
      <- CMALLC (operation incomplete)
   CMCANC ->
      <- CMALLC (allocation_failure_no_retry)
      <- CMCANC OK
   CMINIT ->
      <- CMINIT OK
   CMSPM (set non-blocking mode) ->
      <- CMSPM OK
   CMALLC ->
      <- CMALLC (operation incomplete)
   CMWAIT ->
      <- CMWAIT OK
   CMDEAL ->
      <- CMDEAL (error = state_check)
      <- CMALLC OK

Keywords          : snacpic snaprog kbfix3.00.sp2 kbnetwork kbprg
Version           : 3.0
Platform          : winnt
Issue type        : kbbug
Solution Type     : kbfix