Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (C)
Guardian Procedure Calls Reference Manual—522629-013
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CONTROLBUF Procedure
If a waited CONTROLBUF is executed, the count-transferred parameter
indicates the number of bytes actually transferred.
•
Nowait and count-transferred
If a nowait CONTROLBUF is executed,
count-transferred has no meaning
and can be omitted. A count of the number of bytes transferred is obtained by the
count-transferred parameter of the AWAITIO procedure when the I/O
finishes.
The CONTROLBUF procedure must complete with a call to the AWAITIO
procedure when used with a file opened nowait.
•
When object of CONTROLBUF is not accepting messages
If the object of the CONTROLBUF operation is not accepting process
CONTROLBUF messages, the call to CONTROLBUF completes with condition
code CCG. A subsequent call to FILE_GETINFO_ or FILEINFO shows that an
error 7 (process not accepting process CONTROL, CONTROLBUF, or SETMODE
messages) occurred.
You can obtain the process identifier of the caller to CONTROLBUF in a call to
FILE_GETRECEIVEINFO_ (or LASTRECEIVE or RECEIVEINFO) after you have
read the process CONTROLBUF message.
•
Nonstandard operation and buffer parameters
You can specify any value for the
operation parameter, and you can include any
data in
buffer. An application-defined protocol should be established for
interpreting nonstandard parameter values.
Messages
•
Process CONTROLBUF message
Issuing a CONTROLBUF to a file that represents another process causes a
system message -35 (process CONTROLBUF) to be sent to that process. Refer to
the
Guardian Procedure Errors and Messages Manual for detailed information of
system messages sent to processes.