Re: Enhance.zip

[Robert Holmgren holmgren@xxxxxxxx]

** Reply to note from James Besser 
12/11/95 9:12pm EST

> Tried it; was very impressed with the thoughtful and useful
additions.  > But...I'm getting frequent lockups. The command
line fills up with the  > word "stack," repeated many times, and
the program ceases functioning.

This is a sure sign of OOM phenomena (OutOfMemory), seldom seen
in Xy4 but formerly  very common indeed. In my experience, it
was always due to logical incongruities in  XPL coding, and
never due to the configuration of the implementing user. Reasons
 varied. Sometimes it was triggered by making broad demands on
flaky, narrow-purpose,  marginal commands (the
scarcely-documented RPLFIL is an example). More often, it was
asking the system to do something that was logically impossible
for it to accomplish,  or something that sent it into an endless
logic loop, or something that consumed more  and more memory
without ever releasing it (EXiting). Certain DIRectory commands
place  huge momentary demands on memory resources ("find/pa ?"
crashes two of my machines  forthwith; I now use "find ?").
Ironically, even if it isn't your "fault", you're  probably
going to bear the brunt of isolating the problem, by debugging
the code  carefully, step by step, to find the command that
blows up. OOM symptoms are delicate  and vary with each
machine; like any intermittent problem, very hard to pinpoint and
 fix unless they occur locally.

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Robert Holmgren holmgren@xxxxxxxx
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