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Re: Tweaking atomics and memory barriers in shared_ptr

From: "Jonathan Wakely" <jwakely dot gcc at gmail dot com>
To: "Peter Dimov" <pdimov at mmltd dot net>
Cc: libstdc++ <libstdc++ at gcc dot gnu dot org>, gcc-patches at gcc dot gnu dot org
Date: Sun, 28 Oct 2007 12:50:55 +0100
Subject: Re: Tweaking atomics and memory barriers in shared_ptr
References: <4348dea50710270529q461462d8p553339a37fbd9191@mail.gmail.com> <008501c818a0$a3fcd930$6407a80a@pdimov2>

On 27/10/2007, Peter Dimov <pdimov@mmltd.net> wrote:
>
> Whether use_count() should have acquire semantics instead of relaxed is not
> quite clear even to me. I can think of no legitimate example of inter-thread
> communication via use_count(), so I tend toward "relaxed", which is
> basically why Boost uses a volatile read.

Thanks Peter,
Following that explanation I'll revise the comment in my patch and I
apologise for calling it a hack  :-)
Jon

References:
- Tweaking atomics and memory barriers in shared_ptr
  - From: Jonathan Wakely
- Re: Tweaking atomics and memory barriers in shared_ptr
  - From: Peter Dimov

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