NET/MASTER Network Control Language (NCL) Programmer's Guide

The Dependent Request and Response Queues
Environments and Command Processing
106160 Tandem Computers Incorporated 16–37
The &SYS.INTYPE system variable contains the name of the dependent queue on
which a message has arrived. &SYS.INTYPE contains REQ if the message arrived on
the request queue, or RESP if the message arrived on the response queue. If there is no
message, &SYS.INTYPE contains a null value.
Note Command processing and NCL process execution is asynchronous. Since messages from certain
commands such as the SHOW PARAM, SHOW SYSPARMS, and STATUS command may take some
time to arrive, you must ensure that message arrival and message reading is synchronized. In addition to
the DELAY verb, you can use the WAIT operand in the INTREAD verb to control the timing of message
reading. Use of the DELAY verb and the WAIT operand of the INTREAD verb can affect the performance
of an NCL process.
Clearing Messages in Dependent Queues
You can use the INTCLEAR verb to clear messages in the request and response
queues. You can specify the type of queue using the TYPE keyword. The following
table summarizes the meaning of the qualifiers that can follow the TYPE keyword:
TYPE Qualifier Description
TYPE=ALL This is the default. Clears all messages in the request and response queues.
Dismantles the dependent processing environment. Terminates all commands
and NCL processes running in the environment.
TYPE=ANY Clears all messages in the request and response queues. Does not dismantle the
dependent processing environment. Does not terminate commands and NCL
processes running in the environment.
TYPE=REQ Clears all messages in the request queue. Does not dismantle the dependent
processing environment. Does not terminate commands and NCL processes
running in the environment.
TYPE=RESP Clears all messages in the response queue. Does not dismantle the dependent
processing environment. Does not terminate commands and NCL processes
running in the environment.
The following NCL procedure executes the STATUS command in a dependent
processing environment. It reads the first five messages that arrive on the response
queue and then clears all other messages on the queue.
zex1611n: PROCEDURE
/* Procedure to analyze INTREAD messages */
INTCMD STATUS
DO 5
INTREAD
INTCONT
END
INTCLEAR
END zex1611n