TS/MP Pathsend and Server Programming Manual (H06.05+, J06.03+)

Calling CANCEL or CANCELREQ has these effects on your Pathsend program:
• The program is not affected by any reply to the SERVERCLASS_SEND_,
SERVERCLASS_DIALOG_BEGIN_, or SERVERCLASS_DIALOG_SEND_ call.
• The program cannot determine whether the request message has been sent to a server process,
and if it was sent, whether or not it was canceled before the server process finished processing
the request.
• If the canceled call was to SERVERCLASS_DIALOG_BEGIN_ or SERVERCLASS_DIALOG_SEND_,
the dialog is aborted and the server receives a Pathsend dialog abort system message, even
if the server has already replied to the server-class send operation.
• If the SERVERCLASS_SEND_, SERVERCLASS_DIALOG_BEGIN_, or
SERVERCLASS_DIALOG_SEND_ operation was performed within a TMF transaction, the
transaction is automatically aborted.
On a call to CANCELREQ, you supply:
• The server-class send operation number as the file-number parameter.
• The tag identifying the specific operation to be canceled. (The tag is optional.)
If you use the tag parameter, the system cancels the oldest incomplete SERVERCLASS_SEND_,
SERVERCLASS_DIALOG_BEGIN_, or SERVERCLASS_DIALOG_SEND_ call with that tag value. If
you do not provide a tag, the system cancels the oldest incomplete SERVERCLASS_SEND_,
SERVERCLASS_DIALOG_BEGIN_, or SERVERCLASS_DIALOG_SEND_ call.
On a call to CANCEL, you supply the server-class send operation number as the file-number
parameter.
Refer to the Guardian Procedure Calls Reference Manual for descriptions of the CANCEL and
CANCELREQ procedures.
A cancel operation can also occur if the requester abends while a server-class send operation is
in progress, whether or not the send operation was invoked with the nowait option.
Calling FILEINFO
You can use the server-class send operation number returned by SERVERCLASS_SEND_,
SERVERCLASS_DIALOG_BEGIN_, or SERVERCLASS_DIALOG_SEND_ as the file-number parameter
in calls to FILEINFO to get the return error associated with the last waited or nowait
SERVERCLASS_SEND_, SERVERCLASS_DIALOG_BEGIN_, or SERVERCLASS_DIALOG_SEND_
call. FILEINFO returns the same error that the server-class procedure call returned. See the error
parameter in the procedure-call syntax descriptions earlier in this section for details about the return
errors.
Timeout Considerations for Pathsend Programming
When you design a Pathsend application, you can decide which of two timeout methods that you
want the LINKMON process or the ACS subsystem processes to use:
• A server TIMEOUT attribute that applies only to the server process I/O
• A SERVERCLASS_SEND_, SERVERCLASS_DIALOG_BEGIN_, or SERVERCLASS_DIALOG_SEND_
parameter value that applies to the entire processing of the send request
Because the errors for each are different, programs can differentiate between the two kinds of
timeout.
Server Timeout
You can specify a TIMEOUT attribute for your Pathway servers. You specify the server TIMEOUT
value when you configure the server. If a timeout occurs during an I/O operation to a server, the
I/O operation is canceled and any TMF transaction is aborted. Unlike the timeout parameter to a
SERVERCLASS_SEND_, SERVERCLASS_DIALOG_BEGIN_, or SERVERCLASS_DIALOG_SEND_
106 Pathsend Procedure Call Reference