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

Pathsend Procedure Call Reference
NonStop TS/MP Pathsend and Server Programming Manual–132500
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Usage Considerations for Pathsend Procedures
Usage Considerations for Pathsend Procedures
The following subsections discuss usage considerations that apply to several of the
Pathsend procedure calls.
Condition Code
The condition-code setting has no meaning following a Pathsend procedure call.
Waited I/O
The following considerations apply to waited Pathsend procedure calls:
•
The tag parameter has no meaning and can be omitted.
•
On a successful completion of a waited Pathsend procedure call, the
actual-reply-len parameter indicates the number of bytes in the reply.
For an example of issuing a waited call to SERVERCLASS_SEND_, see the Pathsend
server program example PATHSRV, Example B-2
on page B-53. In this COBOL85
program, paragraph 460-SEND-TO-SUBSIDIARY-SERVER performs a waited
SERVERCLASS_SEND_ call.
Nowait I/O
The following considerations apply to nowait Pathsend procedure calls:
•
The maximum nowait depth for Pathsend procedure calls is 255 per process.
In other words, a Pathsend requester process can have no more than 255 outstanding
nowait server-class send operations at any one time.
•
You complete a nowait Pathsend procedure call with a call to AWAITIOX.
You cannot use the AWAITIO—without the X—procedure to complete a nowait
server-class send operation. The SERVERCLASS_SEND_,
SERVERCLASS_DIALOG_BEGIN_, and SERVERCLASS_DIALOG_SEND_
procedures use a 32-bit extended message buffer address, and AWAITIO cannot be
used to complete extended I/O operations.
If a nowait Pathsend procedure call returns an error, the send operation was not
initiated and therefore does not need to be completed with AWAITIOX.
•
The actual-reply-len parameter has no meaning for nowait server-class send
operations and can be omitted. The count of the number of bytes in the server-class
reply is returned in the count-transferred parameter of the AWAITIOX
procedure.
•
After calling SERVERCLASS_SEND_, SERVERCLASS_DIALOG_BEGIN_, or
SERVERCLASS_DIALOG_SEND_ with the nowait option, do not modify the I/O
buffer before the I/O operation is completed as indicated by AWAITIOX.
•
Nowait server-class send operations must not use buffers that are currently in use for
other outstanding nowait I/O operations. The file system requires that these buffers
not be modified.