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Memory Thermometer under X

    Date: Wed, 20 Nov 1991 23:34-0000
    From: Kanef@CHARON.arc.nasa.gov (Bob Kanefsky)

    For years I and others have been running a memory-visualization tool
    that shows the amount of virtual memory used as a thermometer in the
    margin of the screen, outside the area used by the window system.  (It's
    by DLW, Reti, SGR, and Qobi at MIT, and a 1988 version by Loeffler at
    MCC.)  Now I'm preparing to switch to a UX1200S, which I'll be accessing
    through X windows.  The thermometer tool "doesn't use the window system,
    because [SGR] realized that all the hair in [a previous] window
    implementation was to turn the window system off. This approach avoids
    all kinds of issues, like exposure, activation, the screen manager's
    quaint notion of autoexposure, use of screen space, etc. The result is
    less flexible, but simpler."  Not surprisingly, it's not flexible enough
    to work unmodified under X windows.  Specifically, it fails because the
    :screen-array message returns an object of type tv:remote-indirect-drawable,
    not an array.

    It's an invaluable tool for people with memory-hungry applications.
    (I've had virtual memory filled to the brim with everything from DNA
    sequences to Earth and Mars images to graph-colorability search trees,
    sometimes more than one at once, and I like to know when I have room to
    load one more thing and when I need to Start GC Immediately.)  I'd hate
    to give it up.  Has anyone tried to get it to work under X windows?

    If no one has done so yet, I may give it a shot if I ever have time.  It may
    be that it can be hacked simply to deal with the tv:remote-indirect-drawable
    object.  Better yet, it should be possible to make it run in its own screen in
    a separate X window, which gets around the original exposure issues.


If what you want is simply an indication of unconsumed virtual memory, and don't specifically
need anything graphical, then there is a hack floating around that puts the number of
words of memory left in the status-line where the progress notes usually appear.
Providing there are no other progress notes in operation you get a message like "34,873,344 words left".
I'm not sure who wrote it but it appears to be in reasonably wide circulation here, so I guess I could
mail you a copy if you think it is likely to be a reasonable replacement to the thermometer.
I haven't checked whether it works on a UX, but since it uses the same mechanism as the progress notes
I don't see why it shouldn't work.