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Re: forcing the compiler to reload from memory with c++0x

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From	Anthony Williams <anthony.ajw@gmail.com>
Newsgroups	comp.programming.threads
Subject	Re: forcing the compiler to reload from memory with c++0x
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Date	Fri, 28 Jan 2011 08:12:12 +0000
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frege <gottlobfrege@gmail.com> writes:

> On Jan 27, 6:53 am, Alexander Terekhov <terek...@web.de> wrote:
>> frege wrote:
>>
>> [...]
>>
>> > Anyhow, I would say that this is one of those rare cases where
>> > volatile is the right answer - you just need to adds lots of code
>>
>> Volatile is not the right answer. atomic<> is the rights answer.
>>
>
> Yes, we still need atomic - in the most basic sense - ie an aligned
> int, for example.  But no memory_order_* instructions are needed.

Well, if you use an atomic<int> then you will need to use
memory_order_relaxed explicitly unless you want the default
memory_order_seq_cst.

If you don't use atomic<int> then you have undefined behaviour.

Anthony
-- 
Author of C++ Concurrency in Action     http://www.stdthread.co.uk/book/
just::thread C++0x thread library             http://www.stdthread.co.uk
Just Software Solutions Ltd       http://www.justsoftwaresolutions.co.uk
15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976

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Re: forcing the compiler to reload from memory with c++0x Anthony Williams <anthony.ajw@gmail.com> - 2011-01-28 08:12 +0000
  Re: forcing the compiler to reload from memory with c++0x frege <gottlobfrege@gmail.com> - 2011-01-28 19:47 -0800
    Re: forcing the compiler to reload from memory with c++0x Dmitriy Vyukov <dvyukov@gmail.com> - 2011-01-29 01:43 -0800

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