Guardian Procedure Calls Reference Manual

FILE_OPEN_CHKPT_ Procedure
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Returned Value
Considerations
Example
Summary
The FILE_OPEN_CHKPT_ procedure is called by a primary process to open a designated file for
its backup process. These two conditions must be met before FILE_OPEN_CHKPT_ can be called
successfully:
• The primary process must open the file.
• The backup process must be in the "monitor" state (that is, in a call to CHECKMONITOR).
The call to FILE_OPEN_CHKPT_ causes the CHECKMONITOR procedure in the backup process to
call the FILE_OPEN_ procedure for the designated file.
Syntax for C Programmers
This passive backup procedure is not supported in C programs. For a comparison of active backup
and passive backup, see the Guardian Programmer's Guide.
Syntax for TAL Programmers
error := FILE_OPEN_CHKPT_ ( filenum ! i
,[ status ] ); ! o
Parameters
filenum
input
INT:value
is the number identifying the open file to be opened in the backup process. This value was
returned by FILE_OPEN_ when the file was opened in the primary process.
status
output
INT .EXT:ref
returns a value indicating the cause of the file-system error returned in error. Values are:
Backup open succeeded (error is 0).0
File was opened in backup with warning.1
Open failed in backup.2
Unable to communicate with backup.3
Error occurred in primary.4
FILE_OPEN_CHKPT_ Procedure 471