Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (C)
Guardian Procedure Calls Reference Manual—522629-013
3-8
CANCELREQ Procedure
tag input
INT(32):value
is the tag value passed to the procedure that initialized the I/O operation. It
identifies the operation to be canceled.
Condition Code Settings
< (CCL) indicates that an error occurred (call FILE_GETINFO_ or FILEINFO).
= (CCE) indicates that the operation was canceled.
> (CCG) does not return from CANCELREQ.
Considerations
•
If you use the tag parameter, the system cancels the oldest incomplete operation
associated with that tag value. If you do not provide a
tag, the system cancels the
oldest incomplete operation for
filenum.
•
If you omit the tag parameter, CANCELREQ works exactly like CANCEL.
Messages
The server process receives a system message -38 (queued message cancellation)
that identifies the canceled I/O request, if it has requested receipt of such messages.
Related Programming Manual
For programming information about the CANCELREQ procedure, refer to the Guardian
Programmer’s Guide.