Guardian Procedure Calls Reference Manual

CHECKPOINTMANYX Procedure
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Returned Value
Considerations
Example
Summary
The CHECKPOINTMANYX procedure (like the CHECKPOINTX 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 way. The backup process must be in the "monitor" state (that is, in a call to the
CHECKMONITOR procedure) for the CHECKPOINTMANYX call to be successful.
This procedure can be used to checkpoint:
• Stack data from a specified stack marker to the tip of the stack
• Multiple data areas
• File synchronization blocks
The CHECKPOINTMANYX procedure can be used by both TNS processes and native processes.
It allows checkpointing of data in extended data segments (flat or selectable) in addition to the
user data segment.
You must use CHECKPOINTMANYX if you need to checkpoint more than five data areas. You can
use the CHECKPOINTX procedure instead if you need to checkpoint five or fewer data areas.
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
status := CHECKPOINTMANYX ( [ stack-origin ] ! i
,[ descriptors ] ); ! i
Parameters
stack-origin
input
INT:ref:*
contains an address. CHECKPOINTMANYX checkpoints the process' data stack from the
address in stack-origin through the current tip-of-stack location (‘S'). A checkpoint of the
data stack defines a restart point for the backup process.
See Considerations (page 151) for details.
CHECKPOINTMANYX Procedure 149