Open System Services System Calls Reference Manual (G06.28+, H06.05+)

SPT_FILE_OPEN_(2) OSS System Calls Reference Manual
1 Read only
2 Write only
3 Extend (supported only for tape)
The default is 0 (zero).
exclusion Specifies the desired mode of compatibility with other openers of the
file. Valid
values are:
0 Shared
1 Exclusive
2 Process exclusive
3 Protected
The default is 0 (zero).
nowait_depth Specifies the number of nowait I/O operations that can be in progress for the file
concurrently with other processing. If this parameter is omitted or 0 (zero), only
waited I/O operations are permitted against the file. The maximum value is 1 for
disk files and $RECEIVE. The maximum value is 15 for other objects, except
for the Transaction Monitoring Facility (TMF) transaction pseudofile (TFILE),
which has a maximum of 1000. For details about the TFILE, see the TMF Appli-
cation Programmer’s Guide.
sync_or_receive_depth
The purpose of this parameter depends on the type of device being opened:
disk file Specifies the number of nonretryable (that is, write) requests
whose completion the Guardian file system must remember.
You must specify a value of 1 or greater to recover from a path
failure occurring during a write operation. This value also
implies the number of write operations that the primary process
in a process pair can perform to this file without intervening
checkpoints to its backup process. For disk files, this parameter
is called sync depth. The maximum value is 15.
If omitted, or if 0 (zero) is specified, internal checkpointing does
not occur. Disk path failures are not automatically retried by the
file system.
$RECEIVE file
Specifies the maximum number of incoming messages read by
the SPT_READUPDATEX() function that the application pro-
cess is allowed to queue before corresponding reply operations
must be performed. If omitted or 0 (zero),
SPT_READUPDATEX() and reply operations to $RECEIVE
are not permitted. For $RECEIVE, this parameter is called
receive depth, and the maximum number of queued incoming
messages is 4047.
7−140 Hewlett-Packard Company 527186-007