sync on local variable
in [Java Help]
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From: Roedy Green on 25 Mar 2010 17:29 On Thu, 25 Mar 2010 14:06:53 -0400, Eric Sosman <esosman(a)ieee-dot-org.invalid> wrote, quoted or indirectly quoted someone who said : > Would have been nice of you to point out which of the twelve >source files elicited the complaint ... For others who may want >a look, VerCheck.java seems to be the culprit. Sorry I thought I had pointed you to Vercheck.java. It has since occurred to me I could try concocting a much simpler piece of code without any JTable that still triggered the lint. -- Roedy Green Canadian Mind Products http://mindprod.com If you tell a computer the same fact in more than one place, unless you have an automated mechanism to ensure they stay in sync, the versions of the fact will eventually get out of sync.
From: Roedy Green on 25 Mar 2010 17:32 On Thu, 25 Mar 2010 12:28:45 -0700, Daniel Pitts <newsgroup.spamfilter(a)virtualinfinity.net> wrote, quoted or indirectly quoted someone who said : >Threading isn't that hard to get right, but it isn't that hard to get >wrong either. The only truly difficult part of writing MT code is that >people aren't taught how to look at it and determine whether it is right >or not. The compiler rarely complains and the program nearly always run one thread at a time. You can't easily simulate pathological cases the way you can with single thread. Perhaps there is some drug that induces paranoia that could be used once you have your first cut. -- Roedy Green Canadian Mind Products http://mindprod.com If you tell a computer the same fact in more than one place, unless you have an automated mechanism to ensure they stay in sync, the versions of the fact will eventually get out of sync.
From: markspace on 25 Mar 2010 18:12 Roedy Green wrote: > I got this response from an IntelliJ employee (probably a Russian with > ESL). Hmm, well that's one strike against IntelliJ then, if they don't hire tech support that can communicate properly.
From: Arne Vajhøj on 25 Mar 2010 19:41 On 25-03-2010 17:27, Roedy Green wrote: > On Wed, 24 Mar 2010 15:11:15 -0700, Roedy Green > <see_website(a)mindprod.com.invalid> wrote, quoted or indirectly quoted > someone who said : >> The IntelliJ code Inspector (lint) slapped my wrist for synchronising >> on a local variable. What's the problem with that? The sync is on >> the object, not the reference, right? > > I got this response from an IntelliJ employee (probably a Russian with > ESL). > > The point was synchronization only makes sense if two different > threads syncing on the same instance and question arises how safe was > an exchange, that two threads have same reference on their stacks. > Most obviously "clean" subject to synchronize on is a final field. > Synchronizing on a local reference might well be not a problem but > generally not that easy to verify for correctness and easy thing to > broke later. JetBrains is a czech company, so czech not russian sounds more likely. But the text looks fine to me. It is more or less what we have been telling you for two days. Arne
From: Arne Vajhøj on 25 Mar 2010 19:59
On 25-03-2010 15:28, Daniel Pitts wrote: > Threading isn't that hard to get right, but it isn't that hard to get > wrong either. The only truly difficult part of writing MT code is that > people aren't taught how to look at it and determine whether it is right > or not. That applies to other things than MT! :-) Arne |