TS/MP Pathsend and Server Programming Manual (G06.24+, H06.03+)

Writing Pathsend Requesters
NonStop TS/MP Pathsend and Server Programming Manual–132500
3-10
Cancellation of Server-Class Send Operations
abort occurs. In either case, the requester should abort the transaction when it receives
an error reply.
If the server is shut down by the operator, the following occurs:
•
For dialogs that currently have an I/O operation outstanding, the I/O operation is
first completed, and action is then taken depending on the error value returned:
•
If the I/O operation is completed with an error value of FEOK (0), then the
FEOK value is passed back to the requester along with all user data.
•
If the I/O operation is completed with an error value of FEContinue (70), the
requester receives error 233, FEScError, and SERVERCLASS_SEND_INFO_
returns Pathsend error 929, FEScDialogAborted. No user data is passed back to
the requester.
•
If the I/O operation is completed with any other file-system error, the requester
receives error 233, FEScError, and SERVERCLASS_SEND_INFO_ returns the
file-system error that occurred. No user data is passed back to the requester.
After completion of the I/O operation, the dialog is aborted and the LINKMON
process closes the server process. The server process should interpret the close
operation as a dialog abort.
•
For dialogs that have no I/O operation outstanding, the dialog is aborted and the
LINKMON process closes the server process. The server process should interpret
the close operation as a dialog abort.
When writing requesters as process pairs with or without the TMF subsystem, note that
it is not possible to checkpoint dialogs. The dialog and the transaction, if any, are
aborted when the requester fails.
Cancellation of Server-Class Send Operations
The requester can explicitly cancel an outstanding server-class send operation if it has
used the nowait option in the Pathsend procedure call and has not yet sensed completion
of the server-class send operation through the AWAITIOX procedure. In this case, the
server receives a Pathsend dialog abort system message (as described in Section 4) even
if it has already replied to the last send operation.