Open System Services System Calls Reference Manual (G06.29+, H06.08+, J06.03+)

System Functions (s and S) SPT_WRITEREADX(2)
• If you initiated the I/O with SPT_WRITEREADX( ), the I/O must be
completed with a call to the Guardian AWAITIOX procedure.
• A selectable extended data segment containing the buffer need not be in
use at the time of the call to AWAITIOX.
• You can call SPT_CANCEL() or CANCELREQ to cancel nowait I/O
initiated with SPT_WRITEREADX(). The I/O is canceled if the file is
closed before the I/O completes or if you call the Guardian AWAITIOX
procedure with a positive time limit and specific file number and the
request times out.
Bounds checking
If the extended address of buffer is odd, bounds checking rounds the address to
the next lower word boundary and also checks an extra byte. The odd address is
used for the transfer.
RETURN VALUES
The SPT_WRITEREADX() function returns 0 (zero) upon successful completion. Otherwise,
this function returns a nonzero Guardian file-system error number that indicates the outcome of
the operation.
For information about Guardian file-system error numbers, see the Guardian Procedure Errors
and Messages Manual.
ERRORS
None. This function does not set the errno variable.
RELATED INFORMATION
Functions: SPT_CANCEL(2), SPT_CONTROL(2), SPT_FILE_CLOSE_(2),
SPT_FILE_OPEN_(2), SPT_LOCKFILE(2), SPT_LOCKREC(2), SPT_READLOCKX(2),
SPT_READUPDATELOCKX(2), SPT_READUPDATEX(2), SPT_READX(2),
SPT_SETMODE(2), SPT_UNLOCKFILE(2), SPT_UNLOCKREC(2),
SPT_WRITEUPDATEUNLOCKX(2), SPT_WRITEUPDATEX(2), SPT_WRITEX(2).
STANDARDS CONFORMANCE
This function is an extension to the UNIX 98 specification. Interfaces documented on this refer-
ence page conform to the following industry standards:
• IEEE Std 1003.1c-1995, POSIX System Application Program Interface
The use of the header file spthread.h is an HP exception to the POSIX standard.
527186-023 Hewlett-Packard Company 7−455