TS/MP 2.5 Pathsend and Server Programming Manual

It is also possible to get Pathsend dialog abort messages that do not represent actual aborted
dialogs. A server can receive such a message if the requestor calls SERVERCLASS_DIALOG_BEGIN_
and then cancels the message. In that case, the ACS subsystem ROUT process sends the Pathsend
dialog abort message even though the server might not have received the first message in the
dialog. Similarly, if the requestor calls SERVERCLASS_SEND_ with the nowait option and then
cancels the operation before being notified of completion of the operation through the AWAITIOX
procedure, then the server receives the Pathsend dialog abort message even if it has already replied
to the last send operation.
A cancel operation can also occur if the requestor abends while a server-class send operation is
in progress and whether or not the send operation was invoked with the nowait option.
Handling ACS Subsystem Failures
If the ACS core processes fail or are stopped on a processor, the links that the ROUT process
established with the server processes are relinquished. If any Pathsend dialogs are outstanding at
the time of failure, the dialogs can be considered invalid and must be cleaned up.
Writing Pathway Servers That Interoperate With NonStop Tuxedo
Requestors
A Pathway server can service requests from NonStop Tuxedo requestors (NonStop Tuxedo clients
or NonStop Tuxedo servers acting as clients). Such requestors can make their requests to a Pathway
server in either of two ways:
• Directly, by making calls to the Pathsend procedures described in this manual
• Indirectly, by using the Nonstop Tuxedo to Pathway translation server
Only those NonStop Tuxedo requestors that are NonStop Tuxedo native System/T clients can make
direct requests by using Pathsend procedure calls. For more information, see the NonStop TUXEDO
System Application Development Guide.
Native System /T clients, remote NonStop Tuxedo requestors using System /Domain, and non-native
NonStop Tuxedo workstation clients can indirectly invoke the services of a Pathway server by using
the NonStop Tuxedo to Pathway translation server. If you use this translation server, special
guidelines apply, and you might need to modify the code of existing Pathway servers. For further
information, see the NonStop TUXEDO System Pathway Translation Servers Manual.
Writing Pathway Servers That Interoperate With NonStop Tuxedo Requestors 73