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Groups > comp.lang.java.programmer > #10907
| Newsgroups | comp.lang.java.programmer |
|---|---|
| From | Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> |
| Subject | Re: reading the JLS (17.4.5) |
| References | <slrnjerm1c.fvg.avl@gamma.logic.tuwien.ac.at> <jckv1o$v1v$1@dont-email.me> |
| Message-ID | <slrnjf1iug.fvg.avl@gamma.logic.tuwien.ac.at> (permalink) |
| Date | 2011-12-20 17:54 +0000 |
markspace <-@> wrote: > On 12/18/2011 4:10 AM, Andreas Leitgeb wrote: >> How could a "read" that happens-before a particular "write" *ever* >> see the "write"'s value? > I think you have read it correctly. To elaborate: > > " A set of actions A is happens-before consistent if for all > > " reads r in A, it is not the case that either hb(r, W(r)), > Note that it says "it is NOT the case that ... hb(r, W(r))". The write > DOES have to happen before the read, or you won't see it. That's what > they're saying. Yeah, I was aware of the negation. As I've realized since, my mistake was taking Java's behaviour as a pre-requisite for describing Java's behaviour. ;-) Maybe, however, my mistake was even a bit more complicated. The JLS defines properties (like "happens-before", "happens-before-consistency") on certain entities (pairs of actions, sets of actions). Sometimes, the *non*-applicability of a particular property implies essentially a "flaw" in some program's design (insufficient synchro- nization), but some other times the fulfilment of some other property is meant as a requisite for a conforming JVM-implementation. I guess, I got confused about the implications of the property, based on that it was defined as a property of a set of actions, rather than as a property of a conforming JVM-implementation.
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reading the JLS (17.4.5) Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-12-18 12:10 +0000
Re: reading the JLS (17.4.5) markspace <-@.> - 2011-12-18 06:57 -0800
Re: reading the JLS (17.4.5) Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-12-20 17:54 +0000
Re: reading the JLS (17.4.5) markspace <-@.> - 2011-12-20 10:50 -0800
Re: reading the JLS (17.4.5) Patricia Shanahan <pats@acm.org> - 2011-12-20 12:12 -0800
Re: reading the JLS (17.4.5) Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-12-21 08:54 +0000
Re: reading the JLS (17.4.5) Patricia Shanahan <pats@acm.org> - 2011-12-21 10:56 -0800
Re: reading the JLS (17.4.5) markspace <-@.> - 2011-12-21 12:02 -0800
Re: reading the JLS (17.4.5) Patricia Shanahan <pats@acm.org> - 2011-12-18 09:21 -0800
Re: reading the JLS (17.4.5) Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-12-20 18:35 +0000
Re: reading the JLS (17.4.5) Lew <lewbloch@gmail.com> - 2011-12-20 19:08 -0800
Re: reading the JLS (17.4.5) Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-12-21 08:37 +0000
Re: reading the JLS (17.4.5) Patricia Shanahan <pats@acm.org> - 2011-12-21 10:46 -0800
Re: reading the JLS (17.4.5) markspace <-@.> - 2011-12-21 12:09 -0800
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