CMINIT May Fail with PRODUCT_SPECIFIC_ERROR(20) After a CMCANC

• Microsoft SNA Server for Windows NT, version 2.11 Service Pack 1

SYMPTOMS

When an application issues a cmcanc() call with a cmrcv() outstanding, the CPIC library would release its conversation control block twice. This would cause a subsequent cminit() call to fail with PRODUCT_SPECIFIC_ERROR(20).

CAUSE

When the application issues the cmcanc() verb the outstanding cmrcv() returns with the error, CM_DEALLOCATED_ABEND_SVC. At that point the CPIC library frees the conversation control block. When the cmcanc() verb had finished its processing, it then frees the conversation control block again. This causes the CPIC library's count of active conversations to drop to -1. Because the CPI-C library uses unsigned integers, a negative value of -1 appears as a very large positive number. When the application now issues the next cminit() call the CPIC library checks its count of active conversations, and notice that it was greater than the maximum limit of 16.

With the SNA Application, CPI-C trace enabled you might see the following:

|00000101.000000e0 CPIC   ----------------------------------------------

|00000101.000000e0 CPIC   CMCANC request
|00000101.000000e0 CPIC    Conversation ID = 02000000
|00000101.000000e0 CPIC   ----------------------------------------------

|00000101.000000e0 CPIC   CMRCV async response, result =

|00000101.000000e0 CPIC    Buffer empty
|00000101.000000e0 CPIC    Data received type = CM_INCOMPLETE_DATA_RECEIVED
|00000101.000000e0 CPIC    Received length = 0
|00000101.000000e0 CPIC    Status received = CM_NO_STATUS_RECEIVED
|00000101.000000e0 CPIC    Request to send received =

|00000101.000000e0 CPIC   ----------------------------------------------

|00000101.000000e0 CPIC   CMCANC response, result = CM_OK
|00000101.000000e0 CPIC   ----------------------------------------------

|00000101.000000e0 CPIC   CMINIT request
|00000101.000000e0 CPIC    Sym dest name = LU62TEST
|00000101.000000e0 CPIC   ----------------------------------------------

|00000101.000000e0 CPIC   CMINIT response, result =

|00000101.000000e0 CPIC    Conversation ID = 00000000
|00000101.000000e0 CPIC   Conversation characteristics
|00000101.000000e0 CPIC    Conversation type = CM_BASIC_CONVERSATION
|00000101.000000e0 CPIC    Deallocate type = CM_DEALLOCATE_SYNC_LEVEL
|00000101.000000e0 CPIC    Error direction = CM_RECEIVE_ERROR
|00000101.000000e0 CPIC    Sync level = CM_NONE
|00000101.000000e0 CPIC    Fill type = CM_FILL_LL
|00000101.000000e0 CPIC    Prepare to receive type =

|00000101.000000e0 CPIC    Receive type = CM_RECEIVE_AND_WAIT
|00000101.000000e0 CPIC    Send type = CM_BUFFER_DATA
|00000101.000000e0 CPIC    Conversation security type = XC_SECURITY_NONE
|00000101.000000e0 CPIC    Log data pointer = 00000000
|00000101.000000e0 CPIC    Log data length = 0
|00000101.000000e0 CPIC    Sym dest name =
|00000101.000000e0 CPIC    Partner LU name =
|00000101.000000e0 CPIC   00000000 00000000 00000000 00000000

|00000101.000000e0 CPIC   00                                      <.
>
|00000101.000000e0 CPIC    Mode name =
|00000101.000000e0 CPIC   00000000 00000000                       <........
>
|00000101.000000e0 CPIC    Partner TP name =
|00000101.000000e0 CPIC   00000000 00000000 00000000 00000000

|00000101.000000e0 CPIC   00000000 00000000 00000000 00000000

|00000101.000000e0 CPIC   00000000 00000000 00000000 00000000

|00000101.000000e0 CPIC   00000000 00000000 00000000 00000000

|00000101.000000e0 CPIC   ----------------------------------------------

STATUS

Microsoft has confirmed this to be a problem in Microsoft SNA Server version 2.11.sp1. This problem was corrected in the latest Microsoft SNA Server 2.11 U.S. Service Pack. For information on obtaining the 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

There might be other reasons for getting a PRODUCT_SPECIFIC_ERROR(20) that are not necessarily be related to this article. Further reasons for getting a PRODUCT_SPECIFIC_ERROR(20) can be found in the Knowledge Base articles Q132720 and Q148359.

If you should observe this behavior you will also get the error message 3022 logged in the Application Event Log which indicates an attempt to exceed the maximum number of concurrent CPIC conversations.