Subsystem Control Point (SCP) Management Programming Manual

SPI Programming Considerations for SCP
Subsystem Control Point (SCP) Management Programming Manual—520619-001
3-6
Command-Message Timeout
To messages bound for converted subsystems, an SCP process adds a set of REQID
tokens conveying process identifiers:
For more information on these tokens, see the SPI Common Extensions Manual.
The SCP process forwards these tokens to converted subsystems only. The SCP process
continues to send ZCOM-MAP-REQID to unconverted subsystems. (Subsystems declare
their level of support for D-series data structures by providing an appropriate value for
ZCOM-TKN-GETVSN-LVL in their GETVERSION responses.)
The SCP process does not accept either ZCOM-MAP-REQID or REQID tokens in your
command message unless your PAID is the super ID. If your PAID is the super ID, you
can add REQID tokens to the request. This is required when your application funnels
command messages and responses to and from an SCP process on behalf of other
applications. The originator of the command message must be identified in the
appropriate REQID token.
If your PAID is not the super ID and you include ZCOM-MAP-REQID or REQID tokens
in your command message, the SCP process returns a response containing ZCOM-ERR-
REQID-INV. PAID information is available from the Guardian
PROCESS_GETINFO[LIST]_ procedure.
Command-Message Timeout
Include ZCOM-TKN-CMD-TIMEOUT in a command message to limit the amount of
time that the subsystem has to respond. SCP interprets the value of this token as the
maximum amount of time, in microseconds, that the SCP process will wait for a
subsystem to return a response. The timer starts when the SCP process forwards the
command to the subsystem. If the time limit is exceeded, the SCP process issues a file-
system cancel to cancel the command and then returns a response containing ZCOM-
ERR-CMD-TIMED-OUT.
Canceling a command sent to an SCP process can leave the process in an indeterminate
state. It is possible that part or all of the command has been executed by the time it is
canceled. Your management application should make inquiries to determine the status of
the affected SCP process before proceeding.
REQID Token Value
ZCOM-TKN-REQID-PAID The process access ID of the requester
ZCOM-TKN-REQID-PHANDLE The process handle of the requester
ZCOM-TKN-REQID-PPROGXFILE The program file name of the requester
ZCOM-TKN-REQID-PSTRING The process string of the requester