Guardian Procedure Calls Reference Manual

• If the file is opened for nowait I/O, you must not modify the buffer before the I/O completes
with a call to AWAITIOX. This also applies to other processes that may be sharing the segment.
It is the application's responsibility to ensure this.
• If the file is opened for nowait I/O, and the I/O has been initiated with these routines, the
I/O must be completed with a call to AWAITIOX (not AWAITIO).
• If the file is opened for nowait I/O, the extended segment containing the buffer need not be
in use at the time of the call to AWAITIOX.
• Nowait I/O initiated with these routines may be canceled with a call to CANCEL or
CANCELREQ. The I/O is canceled if the file is closed before the I/O completes or AWAITIOX
is called with a positive time limit and specific file number and the request times out.
• If the extended address of the buffer is odd, bounds checking rounds the address to the next
lower word boundary and checks an extra byte as well. The odd address is used for the
transfer.
Errors for WRITEUPDATEUNLOCKX Only
In addition to the errors returned from the WRITEUPDATEUNLOCK procedure, file-system error 22
is returned when:
• The address of a parameter is extended, but no segment is in use at the time of the call or the
segment in use is invalid.
• The address of a parameter is extended, but it is an absolute address and the caller is not
privileged.
• The file system cannot use the user's segment when needed.
Example
CALL WRITEUPDATEUNLOCK ( OUT^FILE , OUT^BUFFER , 72 , NUM^WRITTEN );
Related Programming Manuals
For programming information about the WRITEUPDATEUNLOCK procedure, see the Enscribe
Programmer's Guide and the Guardian Programmer's Guide.
1520 Guardian Procedure Calls (W-Z)