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

SPT_WRITEX(2) OSS System Calls Reference Manual
• You must not modify the buffer before the I/O completes
with a call to the Guardian AWAITIOX procedure. This
restriction also applies to other processes that might be
sharing the segment. It is the application’s responsibil-
ity to ensure this.
• If you initiated the I/O with SPT_WRITE(), 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 cancel nowait I/O that was initiated with
SPT_WRITEX() with a call to SPT_CANCEL( ) or
CANCELREQ. The I/O is canceled if the file is closed
before the I/O completes or if the Guardian AWAITIOX
procedure is called with a positive time limit and
specific file number and the request times out.
Interprocess Communication Consideration
Indication that the destination process is running
If the SPT_WRITEX() call is to another process, successful completion of the
SPT_WRITEX() call (or a Guardian AWAITIOX procedure call if nowait) indi-
cates that the destination process is running.
RETURN VALUES
The SPT_WRITEX() 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_WRITEREADX(2), SPT_WRITEUPDATEUNLOCKX(2),
SPT_WRITEUPDATEX(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.
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