Guardian Procedure Calls Reference Manual

Returned Value
INT
A file-system error number indicating the outcome of the checkpoint operation. Additional error
information is returned in the status parameter.
Considerations
• Identification of the backup process
The system identifies the backup process to be affected by FILE_OPEN_CHKPT_ 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 the backup process.
• Nowait opens with FILE_OPEN_CHKPT_
If a process is opened in a nowait manner (options.<1> = 1 in the call to FILE_OPEN_), the
backup open is also performed in a nowait manner. It must be completed by a call to
AWAITIO[X], in which case the error and status values are available through
FILE_GETINFOLIST_ items 7 and 8, respectively. If you specify the tag parameter to
AWAITIO[X], the returned value is -29D; the returned count and buffer address are undefined.
• Opens performed through the use of DEFINEs
If the primary process opens a file through the use of a DEFINE, that DEFINE must exist
unchanged when FILE_OPEN_CHKPT_ is called.
• Local setmode operations
All local setmode operations (setmodes that are supported by CHECKSETMODE) that have
been applied to the file since the original open are also applied to the file by
FILE_OPEN_CHKPT_.
• SQL/MX objects
FILE_OPEN_CHKPT_ cannot be called for an SQL/MX object.
• See the FILE_GETSYNCINFO_ procedure Considerations (page 448).
Example
error := FILE_OPEN_CHKPT_ ( file^number, status );
472 Guardian Procedure Calls (F)