topic Re: %LIB-F-INSEF, insufficient event flags in Operating System - OpenVMS

%LIB-F-INSEF, insufficient event flags

Jansen_8 — Wed, 07 Oct 2015 10:47:18 GMT

Hi all,

From one machine I create terminal screen on others by creating a new window (Decwindows) by the DCL-command

$ crea/term set host xxx

I can do that several time until a certain moment when I get

%LIB-F-INSEF, insufficient event flags

and no window is creating.

However each time I delete another window I can replace it with a new one.

Obviously I run into some sort of quota limit. Is there a way to raise the allowed number of event flags?

Regards

Jouk

Re: %LIB-F-INSEF, insufficient event flags

Hoff — Wed, 07 Oct 2015 13:16:28 GMT

There's no quota for event flags.

You probably need to start a new DECterm controller.

Unfortunately and FWIW, event flags have inherent problems, and applications using them for non-trivial tasks don't scale at all well. Event flags are a primitive and problematic mechanism on OpenVMS, and one that is usually best avoided, for all but the most trivial cases. Even for some of the trivial cases, using the "don't care" event flag EFN$C_ENF can be a better approach.

Re: %LIB-F-INSEF, insufficient event flags

John Gillings — Thu, 08 Oct 2015 03:32:10 GMT

Jouk,

Somewhere around I have a procedure which automatically starts a new DECterm controller as a detached process when required. I'll see if I can find it...

Re: %LIB-F-INSEF, insufficient event flags

Jansen_8 — Thu, 08 Oct 2015 06:38:29 GMT

Hoff : thanks for pointing me to the documentation. That solves the problem

John : Yes an automatic procedure would be nice.

Re: %LIB-F-INSEF, insufficient event flags

Hoff — Thu, 08 Oct 2015 15:34:47 GMT

Another option is to use DECnet task-to-task (insecure) or ssh (secure) to launch an X terminal session (DECterm or otherwise) on the remote host, and to then aim the output of that session back to the X Windows server on this box for display.

Variations on this theme:

http://labs.hoffmanlabs.com/node/1524

http://h71000.www7.hp.com/wizard/wiz_5409.html

https://groups.google.com/d/msg/comp.os.vms/n8GIpiDHGc8/OBXWmFi2BS4J

etc.

Current OpenVMS ssh does support the execution of user-specified one-shot commands on the remote host, too.

ssh can also set up the remote display path, using -Y or similar.

Variations:

http://labs.hoffmanlabs.com/node/134