HP TACL Programming Manual page 128

Initiating and Communicating With Processes
Using INV and OUTV
5–20
Stopping a Process That uses INV and OUTV
A process that uses INV and OUTV remains in existence until one of the following
conditions occurs:
The originating process sends an exit message to the process. The exit message
can be defined by the process (such as EXIT for FUP). Some processes accept
an end-of-file indicator as a termination request. For example, an EDIT process
started by the command:
EDIT /INV in_var DYNAMIC/
stops as soon as it reads an end-of-file produced by
#EOF in_var
In other cases, you can use #SERVER with the KILL option.
You log off.
The process finishes its work and stops its own execution.
The originating process terminates.
TACL supports a STATUS option that stores an indication of why the process
terminated. The possible indications are STOP, ABEND, CPU (CPU failure), and NET
(network failure).
Limitations on the Use of INV and OUTV
Each process is associated with three to four variables. A particular variable level can
be associated with only one process at a time.
A TACL process can have a maximum of 100 simultaneous openers, including active
processes using variables for STATUS, PROMPT, INV, OUTV, or #REQUESTER.
Multiple openers of a given process must use the process with care: If one opener has
issued a WRITEREAD and is waiting for data to be appended to the IN variable of the
process, any other openers attempting to do likewise receive a file system error 28.
You can specify the NOWAIT option with INV and OUTV. You must specify the
NOWAIT option if you wish to examine the OUTV, PROMPT, or STATUS variables
while the process is running, or if you use DYNAMIC INV.
If your TACL process ends, processes having it open receive a file-system error 66
(device downed) on all further operations after it is deleted.
If you delete a variable level (with #POP, #UNFRAME, or #KEEP) that is being used
by a process as an INV, OUTV, PROMPT, or STATUS variable, TACL continues to
send the contents to the process, but you can no longer access the variable level from
TACL. If you use the variable as a DYNAMIC INV variable, any further references to
the variable by the process receive a file system error 66 once all data has been
transferred.
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