Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (C)
Guardian Procedure Calls Reference Manual—522629-013
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CHECKPOINT Procedure
(Superseded by CHECKPOINTX Procedure )
CHECKPOINT Procedure
(Superseded by CHECKPOINTX Procedure
)
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Considerations
Summary
The CHECKPOINT procedure is called by a primary process to send information about
its current executing state to its backup process. The checkpoint information enables
the backup process to recover from a failure of the primary process in an orderly
manner. The backup process must be in the “monitor” state (that is, in a call to the
CHECKMONITOR procedure) for the checkpoint to be successful.
Syntax for C Programmers
This passive backup procedure is not supported in C programs. For a comparison of
active backup and passive backup, refer to the
Guardian Programmer’s Guide.
Syntax for TAL Programmers
Parameters
status returned value
INT
returns a status word of the following form:
<0:7> = 0 No error
<0:7> = 1 No backup process or unable to communicate with backup
process; then
<8:15> = file-system error number
Note. This procedure cannot be called by native processes. Although this procedure is
supported for TNS processes, it should not be used for new development.
status := CHECKPOINT
( [ stack-origin ], [ buffer-1 ], [ count-1 ] ! i,i,i
, [ buffer-2 ], [ count-2 ] ! i,i
. .
. .
. .
, [ buffer-13 ], [ count-13 ] ); ! i,i