VMS Process logicals in phweb

[Chris Sharman]

The only hazards I can see are the subprocess issue, which you've covered,
the close (which you've covered) which will be needed in all relevant
screens, and the timing of the open, which I don't know.
Does Quick open files before or after running initialize ? Or does it just
open them 'on demand' ? The existence of a close verb, but no open, would
seem to imply this, in which case you're safe. Failing that, you may have to
set your logical in a parent screen, to ensure it's set before the subscreen
runs.

I think you're right to not bother with the logout to tidy up the
subprocess - it's a significant overhead you don't need. DCL subprocesses
shouldn't rely on transient symbols & process logicals anyway - it's not
safe, as you've observed.

Chris

-----Original Message-----
From: Miller, Daniel [mailto:daniel.miller@nightfreight.co.uk]
Sent: 22 January 2003 17:49
To: powerh-l@lists.swau.edu
Subject: RE: VMS Process logicals in phweb


Hi again,
An update:
Im doing this so that a phweb screen can access a different parameter file
each time it runs, I have added the setsystemval and deletesystemval for a
file i want to reference in the screen.  I have also had to add a "close"
for the file.
The other issue thats came up so far is when doing "run command" it starts a
subprocess which inherits the logical for the file.  I remember this being
an issue when useing normal ph screens to run quiz and trying to pass
parameters as logicals (Use the job logical table not the process).
The dcl subprocess stays around as long as the webserver process does (so
between running the screen multiple times), but it keeps the logical from
the first time the screen ran (in the parent webserver process where the
screen seems to run the logical has changed each time).  Found something
about doing run command "logout" to kill the subprocess each time, but the
dcl commands im doing dont involve the logical anyway so ive left it the way
it is.
Daniel Miller
Nightfreight
 -----Original Message-----
From:   Miller, Daniel
Sent:   Wednesday, January 22, 2003 10:24 AM
To:     Powerhouse List 3 (E-mail)
Subject:        VMS Process logicals in phweb
Hi,
We have a webserver on a Win 2000 machine and a dispatcher and phwebservers
on an alpha running vms 7.3.
Afaik if a webserver is busy another one starts (up to a predefined limit
set in the administrator of course), the webservers do not handle more than
one user at a time.  I can see that each webserver is a separate subprocess
of the dispatcher process.
What i want to do is use setsystemvalue to set a process logical to use in
the phweb screen in possibly the initialize procedure and then do a
deletesystemvalue after.  I cant see a reason why any other users should be
able to see this process logical, does anyone think there could be a problem
with this?
tia,
Daniel Miller
Nightfreight



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