Article View: comp.sys.amiga.tech
Article #9766Negative Open Counts (was Re: IEEE libraries)
From: Robert Eachus
Date: Mon, 12 Sep 1988 19:02
Date: Mon, 12 Sep 1988 19:02
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2330 bytes
What we need is an upwardly compatible solution which does not
cause existing correct programs to Guru if some other task fouls
things up. The following suggestion points the way:
>In article <1570@sbcs.sunysb.edu> root@sbcs.sunysb.edu (root) writes:
>>
>> No, please no more GURU conditions. It seems to be that a reasonable
>> thing to do is when the count would go negative just mark the
>> library as permanently open and ignore any further closes.
If setting the open count negative makes a library permanently
resident (at least till the next warm boot, or someone intentionally
diddles the bits) we get the following rule:
When a library is opened by a task, if the (open) count is
non-negative, increment it by one. When a library is closed
decrement the count by one. Libraries may only be unloaded
when the count is zero.
Simple and sweet. I like the idea of ratcheting the count down,
but setting all negative counts to minus one or some other value is
equally acceptable. In any case, other than to very simple OS
changes, no fuss, no bother. It might be nice to add a make
permanently resident call, and a force unload utility, but these are
frills. And it is all very useful. A library could force itself to
stay resident if it opened a resouce behind the users back when it
needed to maintain state. (Such a library would have to track itself,
but this shouldn't be hard if it is needed.)
Robert I. Eachus
with STANDARD_DISCLAIMER;
use STANDARD_DISCLAIMER;
function MESSAGE (TEXT: in CLEVER_IDEAS) return BETTER_IDEAS is...
Technical Details
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<1356@percival.UUCP> <b03Kac9bnd10108qAIk@amdahl.uts.amdahl.com> <358@boing.UUCP> <1570@sbcs.sunysb.edu> <362@boing.UUCP>Show Full Headers
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!lll-winken!lll-tis!ames!mailrus!tut.cis.ohio-state.edu!husc6!linus!mbunix!eachus From: eachus@mitre-bedford.ARPA (Robert Eachus) Newsgroups: comp.sys.amiga.tech Subject: Negative Open Counts (was Re: IEEE libraries) Summary: A compatible fix. Keywords: open counts Message-ID: <39822@linus.UUCP> Date: 12 Sep 88 19:02:13 GMT References: <1356@percival.UUCP> <b03Kac9bnd10108qAIk@amdahl.uts.amdahl.com> <358@boing.UUCP> <1570@sbcs.sunysb.edu> <362@boing.UUCP> Sender: news@linus.UUCP Reply-To: eachus@mitre-bedford.ARPA (Robert I. Eachus) Distribution: na Organization: The MITRE Corporation, Bedford, Mass. Lines: 35