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Groups > comp.lang.java.programmer > #10805
| From | Gene Wirchenko <genew@ocis.net> |
|---|---|
| Newsgroups | comp.lang.java.programmer |
| Subject | Re: Question whether a problem with race conditions exists in this case |
| Date | 2011-12-16 10:09 -0800 |
| Organization | A noiseless patient Spider |
| Message-ID | <962ne7lihv060mfbtvpspdgc9c4pd854po@4ax.com> (permalink) |
| References | (2 earlier) <8946607.360.1323888252717.JavaMail.geo-discussion-forums@prfb7> <slrnjei4fi.fvg.avl@gamma.logic.tuwien.ac.at> <alpine.DEB.2.00.1112151445530.21168@urchin.earth.li> <j3kke7h2dbgp8glmlof48anr47najpk0rm@4ax.com> <alpine.DEB.2.00.1112161403470.30461@urchin.earth.li> |
On Fri, 16 Dec 2011 14:06:06 +0000, Tom Anderson
<twic@urchin.earth.li> wrote:
>On Thu, 15 Dec 2011, Gene Wirchenko wrote:
>
>> On Thu, 15 Dec 2011 14:58:04 +0000, Tom Anderson
>> <twic@urchin.earth.li> wrote:
>>
>> [snip]
>>
>>> The rules for working out happens-before relationships are simple. At
>>> least, the fundamental idea is simple; the details of exactly when a
>>> relationship arises are less simple, but if you know the few most
>>> important ones, you will be fine most of the time. *Every Java programmer
>>> should know these rules*.
>>>
>>> To paraphrase the JLS slightly, they are:
>>>
>>> 1. If x and y are actions of the same thread and x comes before y in
>>> program order, then x happens before y
>>>
>>> ('actions' mostly means reads and writes on memory, and a few other, less
>>> important things; 'program order' means the order of actions within a
>>> single thread)
>>
>> Is this actually the case? IIRC, C has an as-if rule. An
>> implementation can break the rules if it can be guaranteed that the
>> result will be the same as if the rules were followed.
>
>Possibly. But i don't really know what such a rule really even means; how
>could you have a rule that banned as-if behaviour? How would that be
>enforced? How could you tell if it was being broken? Isn't there an
>implicit as-if rule in every specification? It seems like a meaningless
>thing to state explicitly.
A language might have a rule that a certain case must be handled
in a certain way.
If a compiler could determine in code analysis that that case
could never occur, then it could omit generating code that handled
that case.
Sincerely,
Gene Wirchenko
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Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-14 09:07 -0800
Re: Question whether a problem with race conditions exists in this case Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-12-14 17:53 +0000
Re: Question whether a problem with race conditions exists in this case Lew <lewbloch@gmail.com> - 2011-12-14 10:44 -0800
Re: Question whether a problem with race conditions exists in this case Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-12-14 10:54 -0800
Re: Question whether a problem with race conditions exists in this case Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-12-14 21:15 +0000
Re: Question whether a problem with race conditions exists in this case Tom Anderson <twic@urchin.earth.li> - 2011-12-15 14:58 +0000
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-15 08:40 -0800
Re: Question whether a problem with race conditions exists in this case Gene Wirchenko <genew@ocis.net> - 2011-12-15 11:55 -0800
Re: Question whether a problem with race conditions exists in this case Tom Anderson <twic@urchin.earth.li> - 2011-12-16 14:06 +0000
Re: Question whether a problem with race conditions exists in this case Gene Wirchenko <genew@ocis.net> - 2011-12-16 10:09 -0800
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-14 11:47 -0800
Re: Question whether a problem with race conditions exists in this case Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-12-14 10:53 -0800
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-14 11:54 -0800
Re: Question whether a problem with race conditions exists in this case Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-12-15 16:38 -0800
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-15 23:01 -0800
Re: Question whether a problem with race conditions exists in this case Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-12-16 09:34 -0800
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-17 11:55 -0800
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-19 05:33 -0800
Re: Question whether a problem with race conditions exists in this case Lew <lewbloch@gmail.com> - 2011-12-14 11:04 -0800
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-14 12:32 -0800
Re: Question whether a problem with race conditions exists in this case markspace <-@.> - 2011-12-14 14:13 -0800
Re: Question whether a problem with race conditions exists in this case Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-12-14 17:44 -0500
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-14 14:50 -0800
Re: Question whether a problem with race conditions exists in this case markspace <-@.> - 2011-12-14 15:26 -0800
Re: Question whether a problem with race conditions exists in this case Lew <lewbloch@gmail.com> - 2011-12-15 01:34 -0800
Re: Question whether a problem with race conditions exists in this case Andreas Leitgeb <avl@gamma.logic.tuwien.ac.at> - 2011-12-14 21:38 +0000
Re: Question whether a problem with race conditions exists in this case Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-12-14 16:26 -0500
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-14 13:57 -0800
Re: Question whether a problem with race conditions exists in this case Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-12-14 18:05 -0500
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-14 23:25 -0800
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-14 23:28 -0800
Re: Question whether a problem with race conditions exists in this case Tom Anderson <twic@urchin.earth.li> - 2011-12-15 14:44 +0000
Re: Question whether a problem with race conditions exists in this case Lew <lewbloch@gmail.com> - 2011-12-16 08:27 -0800
Re: Question whether a problem with race conditions exists in this case Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-12-16 09:41 -0800
Re: Question whether a problem with race conditions exists in this case Tom Anderson <twic@urchin.earth.li> - 2011-12-16 18:51 +0000
Re: Question whether a problem with race conditions exists in this case Tom Anderson <twic@urchin.earth.li> - 2011-12-16 18:50 +0000
Re: Question whether a problem with race conditions exists in this case Saxo <saxo123@gmx.de> - 2011-12-14 14:13 -0800
Re: Question whether a problem with race conditions exists in this case Lew <lewbloch@gmail.com> - 2011-12-14 16:55 -0800
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