Re: new module 'duplocale'

[Ludovic Courtès]

Hi Bruno,

Bruno Haible <address@hidden> writes:

>> >       const char *base_name = nl_langinfo (_NL_LOCALE_NAME (LC_CTYPE));
>> 
>> This is not thread-safe but I guess there’s no other choice.
>
> This code is only used on glibc systems, and nl_langinfo is multithread-safe
> on glibc systems (by code inspection and due to the way it mmaps the locales).
> This means, as long as no thread is calling setlocale, all threads can use
> all locale functions in parallel without interference. If you call setlocale
> while other threads are using locales, you are out for trouble anyway.

OK, good to know.

>> Presumably an ‘nl_langinfo_l’ module could build on the ‘duplocale’
>> module like this:

[...]

> Such code is better written to use uselocale(), which does normally not
> cause memory allocation.

Right.

> You can define such a function for yourself; I agree with Ulrich, Jakub, and
> Eric that this functionality should not be in POSIX and hence also not
> necessarily in gnulib.

Well, as we discussed, an interpretation of
http://www.opengroup.org/onlinepubs/9699919799/basedefs/locale.h.html is
that ‘LC_GLOBAL_LOCALE’ can be used anywhere a ‘locale_t’ is expected.

Then again, I understand the performance concerns...

Thanks,
Ludo’.