SPI Common Extensions Manual

Subsystem Control Point
SPI Common Extensions Manual—427508-001
3-5
Command Timeout
To messages bound for C-series subsystems, an SCP process adds ZCOM-MAP-
REQID, which contains the process ID (CRTPID) and process access ID (PAID) of the
requester. Every process has a unique, four-word CRTPID. The PAID represents the
process owner. The left byte of the PAID is the group number, and the right byte is the
user number.
To messages bound for converted subsystems, a D-series SCP process adds a new
set of REQID tokens conveying D-series process identifiers:
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.)
If an application funnels command messages and responses to and from an SCP
process for other applications, it must add requester identification tokens to the
commands. The SCP process does not accept either ZCOM-MAP-REQID or the D-
series REQID tokens in your command message unless your PAID is the super ID.
The originator of the command message must be identified using the appropriate
REQID token.
If an application’s PAID is not the super ID and the application includes ZCOM-MAP-
REQID or the D-series REQID tokens in a command message, the SCP process
returns a response containing ZCOM-ERR-REQID-INV. PAID information is available
from the PROCESS_GETINFO[LIST]_ procedure.
Command Timeout
The SCP process looks for ZCOM-TKN-CMD-TIMEOUT in the command message.
The value of ZCOM-TKN-CMD-TIMEOUT specifies the maximum amount of time, in
microseconds, that the SCP process waits for a subsystem to return a response. The
timer for this operation starts counting when SCP 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 returns a response containing ZCOM-ERR-CMD-TIMED-
OUT.
Command cancellation can leave a subsystem and its objects in an indeterminate
state. Part or all of the command might have been executed before it times out. An
application should make inquiries to determine the status of affected objects before
proceeding.
D-Series REQID Token Value Page
ZCOM-TKN-REQID-PAID The process access ID of the requester 4-13
ZCOM-TKN-REQID-PHANDLE The process handle of the requester 4-14
ZCOM-TKN-REQID-PPROGXFILE The program file name of the requester 4-14
ZCOM-TKN-REQID-PSTRING The process string of the requester 4-15