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From: kilgallen@eisner.decus.org (Larry Kilgallen)
Subject: Re: File/Record locking in Ada
Date: 1997/03/03
Message-ID: <1997Mar3.141549.1@eisner>#1/1
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References: <3313101D.1BBF@aston.ac.uk> <01bc259a$a035e850$fc00af88@godiva>
 <c4ohd0ncig.fsf@hc17031.hcsd.ca>
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Date: 1997-03-03T00:00:00+00:00
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In article <c4ohd0ncig.fsf@hc17031.hcsd.ca>, demer@hc17031.hcsd.ca (David Emery) writes:
> Just remember that in POSIX, file locks are advisory.

Good point.

In fact, any "locking" scheme voluntarily added to an Ada program
presumes that all other accessors will play be the same rules.

The only way to _guarantee_ that locks are respected is to have
a mechanism which is tied into the record access method, which
means an end to free-form data access which might be present in
an existing Ada program.  Only if that record access method
can be guaranteed to always be used (such as by interaction
with operating system inner modes) is a file or record lock
guaranteed.

Larry Kilgallen