From: Robert A Duff <bobduff@shell01.TheWorld.com>
Subject: Re: Protected Objects - eggshell model
Date: Tue, 23 Dec 2008 19:49:07 -0500
Date: 2008-12-23T19:49:07-05:00 [thread overview]
Message-ID: <wccr63ymm7w.fsf@shell01.TheWorld.com> (raw)
In-Reply-To: 63bd094e-8980-4b47-8e34-3d3d6f3b67d2@e1g2000pra.googlegroups.com
hesobreira <herrsobreira@gmail.com> writes:
> This was not clear to me while reading Barnes' book about protected
> types.
>
> There are two conditions that must be satisfied in order to execute
> the entry call: no other task accessing the object at the same time
> and the condition barrier evaluated to TRUE (eggshell, or two level
> protection model). My question is: which one of these conditions is
> evaluated first, the access lock or the condition barrier?
The barrier is likely looking at variables that are protected by the
lock. So the lock must be obtained first.
- Bob
prev parent reply other threads:[~2008-12-24 0:49 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-23 22:08 Protected Objects - eggshell model hesobreira
2008-12-24 0:43 ` Adam Beneschan
2008-12-25 14:29 ` hesobreira
2008-12-24 0:49 ` Robert A Duff [this message]
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