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From: markspace <-@.>
Newsgroups: comp.lang.java.programmer
Subject: Re: AtomicReferenceArray writes and visibility
Date: Thu, 31 Mar 2011 21:58:20 -0700
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On 3/31/2011 9:54 PM, Peter Duniho wrote:
> On 3/31/11 9:22 PM, markspace wrote:
>> [...]
>> Read the source code for the AtomicReferenceArray. set() doesn't use any
>> synchronization. It calls sun.misc.Unsafe#putObjectVolatile(). I don't
>> see how that's going to create a happens-before.
>
> "volatile" creates the happens-before. All writes before a volatile
> write in the same thread must be visible in a given thread after a
> volatile read in the same thread from the same location.


I didn't notice the keyword volatile there.  Did I miss it?

Regardless, the lack of any guarantees in the docs of 
AtomicReferenceArray would kill it for me.  You can't be sure how the 
implementation will change over time.