Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!apple!ames!think!bloom-beacon!mit-eddie!apollo!oj
From: oj@apollo.COM (Ellis Oliver Jones)
Newsgroups: comp.sys.apollo
Subject: Re: Processes in GPR_$borrow mode
Summary: There's no way to break through borrow mode
Message-ID: <437533e0.d5b2@apollo.COM>
Date: 26 May 89 19:51:00 GMT
References: <8905250301.AA25073@umix.cc.umich.edu>
Reply-To: oj@apollo.com (Ollie Jones)
Organization: Apollo Computer, Chelmsford, MA
Lines: 46

In article <8905250301.AA25073@umix.cc.umich.edu> GBOPOLY1@NUSVM.BITNET (fclim) writes:
>I need to how user.sys_admin, root or
>user.locksmith may send a message via send_alarm (or Unix write(1)) to
>a node that is running a program in GPR_$borrow mode.

Once a process is using the display via GPR in borrow mode, there's 
No Way for any other process to "break through" and write to the screen.
There's no graphical facility similar to 
the "broadcast" stuff provided by the DEC
VMS system for sending messages to serial terminals, regardless of
the privilege level of the sender.  Sorry.

May I suggest some alternatives which might meet your need?

(1) build some sort of message facility into your borrow mode
    application...have it watch some incoming mailbox or
    socket, and display whatever it receives.  The problem
    here is that it requires programming, and probably requires
    modification to the core main loop of your application.

(2) have a privileged message facility deliver some sort of
    signal (or fault, if you want to speak Aegis) to 
    your application.   SIGWINCH might be suitable.  You
    could put a fault handler in the application, and
    display a message (after, perhaps, reading it from a 
    well-known file).  Again, this requires application changes.

(3) Just use the alarm server.  The bell still rings, even though
    you can't see the popup.  Train your users to pay attention
    to random bells.  (On my node, my disk chatters when I get
    an alarm, so I can tell when it's a real alarm and
    when it's the application program beeping at me.)  Leave
    off the -bell1 option on the alarm server, and it provides
    different kinds of beep signals, precisely because of this
    borrow mode problem.

(4) Use the tone_$time call (see /sys/ins/tone.ins.pas) to
    issue an obnoxiously long beep sound, or morse code signals
    (like the  ... - - - ... the alarm server issues when it's
     about to crash).

Sorry I don't have a better answer.

/Ollie Jones (speaking for myself, not necessarily for the Apollo
              Division of the Hewlett-Packard Company, which, btw,
              is what we're called now.)