[daip] XAS using INET

[Eric Greisen]

Ben Jarvis writes:
 > The users tell me the AIPS cookbook says that AIPS will only allow one
 > INET sockets based XAS session at a time, but allows 0-Z UNIX sockets.
 > Is it still true that there is a limit of one INET session, and if so,
 > why?  We've been having problems involving one user starting AIPS
 > without specifying tv=local:0, then anyone else that runs that way
 > can't get any XAS/MSGSRV/TEKSRV windows because the first user is
 > already running them.  Other times /tmp fills up with XAS sockets which
 > are never removed and eventually users get "No free sockets" when they
 > try to start up.  I thought using INET sockets instead would be a good
 > way to rememdy some of this, but if it only takes one connection at a
 > time, I'm not so sure.  What's the best way to manage all these
 > sessions issues? 


We use specific socket numbers for the Inet sockets, so only one
process can use them.  I take it that your users are using one central
computer with Xterminals.  That is the only situation where it is at
all sensiobsible to end up in the situation you describe.  Thus XAS
runs in the central machines but with $DISPLAY set to the Xterminals.
The AIPS solution for this is for users to use the verb KLEENEX when
they exit their AIPS session rather than EXIT.  This clears away the
XAS etc that they are using incl the Inet socket or /tmp sockets.
Otherwise, the XASn goes on running and will resume for that user
($DISPLAY value).

If you are not running from Xterminals, then you should be running XAS
etc on the users desktops even if the main computer is doing the
number crunching.  Then one says TV=desktop:desktop.

Eric Greisen