Re: [boost] [filesystem] path thread safety fix impact on POSIX systems

Subject: Re: [boost] [filesystem] path thread safety fix impact on POSIX systems
From: Beman Dawes (bdawes_at_[hidden])
Date: 2011-12-31 18:14:21

On Fri, Dec 30, 2011 at 12:44 PM, Mathias Gaunard
<mathias.gaunard_at_[hidden]> wrote:
> On 12/30/2011 02:48 PM, Beman Dawes wrote:
>>
>> Class path locale initialization has suffered from a data race for
>> several releases.
>> See https://svn.boost.org/trac/boost/ticket/6320 for an example of
>> code that suffers as a result.
>>
>> The problem was introduced when locale initialization was changed from
>> namespace scope initialization to function scope initialization. For
>> Windows and Mac OS X, the fix is simply to change back to namespace
>> scope initialization.
>>
>> For non-BSD based POSIX systems such as Linux, the problem is more
>> complex. These system need std::locale(""), "the locale-specific
>> native environment".
>
>
> From what you're saying, function-scope static initialization is only
> required on Linux.

That seems the easiest and most robust solution, particularly if class
path continues to throw on locale("") errors.

>
> Then you say that the problem is that function-scope static initialization
> is not thread-safe.
>
> But function-scope static initalization is thread-safe with conforming
> C++11 compilers, and has been thread-safe with GCC and other compilers that
> follow the Itanium ABI for a fairly long time.
>
> So the problem seems to be non-existent.

What about other compilers on Linux, like Intel and Clang? Any clue?

--Beman