Restrictions on abnormally deallocating conversations

Conversations can be abnormally terminated by either partner. The macroinstructions used to abnormally end the conversation can be issued while other APPCCMD macroinstructions are outstanding on the conversation, in which case the outstanding macroinstruction is canceled and the conversation terminated. Cases do exist where the CONTROL=DEALLOC or CONTROL=DEALLOCQ macroinstructions cannot be issued while another APPCCMD macroinstruction is outstanding on a conversation. In addition, the abnormal termination macroinstructions cannot be used to cancel a macroinstruction that does not specify a conversation resource, such as the APPCCMD CONTROL=OPRCNTL macroinstructions. The macroinstructions that cannot be canceled by one of the abnormal termination APPCCMD CONTROL=DEALLOC or CONTROL=DEALLOCQ macroinstructions are:

APPCCMD CONTROL=SEND, QUALIFY=CONFIRM (or any other APPCCMD that is waiting for a confirmation response or error log data)
APPCCMD CONTROL=RECEIVE, QUALIFY=SPEC (that has not received any data from the partner LU to send a negative response to)
APPCCMD CONTROL=RECEIVE, QUALIFY=ANY (that has not been matched to a conversation)
APPCCMD CONTROL=RCVFMH5
APPCCMD CONTROL=RESETRCV
APPCCMD CONTROL=OPRCNTL
APPCCMD CONTROL=REJECT, QUALIFY=CONV
APPCCMD CONTROL=REJECT, QUALIFY=SESSION
One of the other abnormal termination CONTROL=DEALLOC macroinstructions

The application program can wait for these macroinstructions to complete, or it can issue APPCCMD CONTROL=REJECT, QUALIFY=CONV to cancel an outstanding macroinstruction on a conversation. The only conversation-related macroinstruction that APPCCMD CONTROL=REJECT, QUALIFY=CONV cannot cancel is another APPCCMD CONTROL=REJECT, QUALIFY=CONV macroinstruction.

The abnormal termination APPCCMD CONTROL=DEALLOC|DEALLOCQ macroinstructions are always unconditional. The conversation terminates after their completion. If the application program needs to supply error log data on the macroinstruction, it must supply the complete error log variable. It cannot use any subsequent macroinstructions to finish sending the data. (See Error log variables for a description of the error log variable.) The partner can only receive error log data. As soon as it finishes receiving the data (if supplied), the conversation is finished.

When an application program issues an abnormal termination APPCCMD CONTROL=DEALLOC|DEALLOCQ macroinstruction, data purging or truncation can occur. Data truncation occurs when the application program is in a sending state and issues the macroinstruction before providing the remainder of a logical record. Data purging occurs when the application program issues the macroinstruction in a receiving state before receiving all the information sent by the partner. Any data buffered by VTAM® and waiting for a RECEIVE macroinstruction is discarded. For more information on purging, see Data purging and truncating.