Guardian Procedure Calls Reference Manual

backerror
output
INT:ref:1
returns one of these values:
is the file-system error number reflecting the call to FILE_OPEN_ in the backup process.Š0
indicates that the backup process is not running or that the checkpoint facility could not communicate
with the backup process.
-1
Condition Code Settings
These settings are obtained from the FILE_OPEN_ procedure in the backup process:
indicates that the open failed. The file-system error number returns in backerror.< (CCL)
indicates that the open was successful.= (CCE)
indicates that the open was successful, but an exceptional condition was detected. The file-system error
number returns in backerror.
> (CCG)
Considerations
• Identification of the backup process
The system identifies the process to be affected by CHECKOPEN from the process' mom field
in the process control block (PCB). For named process pairs, this field is automatically set up
during the creation of a backup process.
• Nowait opens with CHECKOPEN
If a process file is opened nowait (flag.<8> = 1 with OPEN, options.<1> = 1 with
FILE_OPEN_ ), that file is CHECKOPEN nowait. CHECKOPEN returns errors detected in
parameter specification and system data-space allocation in backerror and the operation
is considered complete.
If no error is returned in backerror, the operation must be completed by a call to AWAITIO
in the primary process. If you specify the tag parameter, the value returned by AWAITIO is
-29D; the returned count and buffer address are undefined. If the condition code CCL is
returned by AWAITIO, the file is automatically checkclosed by the checkpointing facility. For
a nonprocess file or a process file that is opened in a waited manner, bit <8> of the flag
parameter is reset internally to zero and ignored.
• Primary process open
A backerror value of 17 is returned if a device or process being opened is not, in its own
view, currently open by the primary process. This can occur, for example, after a device has
been brought UP or DOWN.
• See the OPEN procedure Considerations (page 901).
• Opening a Licensed object file with write or read-write access turns off the License attribute,
even if opened by the super ID.
Messages
• Unable to communicate with backup
If an "unable to communicate with backup" error occurs (that is, backerror = -1), it normally
indicates either that the backup process does not exist or that a system resource problem
exists.
CHECKOPEN Procedure (Superseded by FILE_OPEN_CHKPT_ Procedure) 141