Valery Aronov <valery@ind.tansu.com.au> wrote:
How is it possible to manage current zone information in MT-safe fashion?
From: Paul Eggert <eggert@twinsun.com>
Write and use a thread-safe version of the tz library.
This requires changing the interfaces to localtime, gmtime, tzset, etc. (localtime_r is not enough.) One must also make the locale a parameter, for strftime at least. And I'm afraid that this will require going into the guts of the C library, which will make it hard to do portably.
On my (long) list of things to do is to make a thread-safe version of the glibc version of the tz library. Once you know you're dealing with that particular library, the job becomes tractable.
The non-re-entrancy, and the globalness, of the time functions has long bothered me. With the C locale itself global, there's not much to be done about that. The (draft) standard C++ locale is not (necessarily) global, and supports user extensions such as time zone handling. Now would be a good time to start defining a standard time zone facet for the C++ locale, so that it can be made official at the next round, in a few years. The glibc locale functions being worked on by Ulrich Drepper are designed to support a re-entrant (C) interface. We should co-ordinate with him to get the time zone code integrated into his architecture. Please, let's get the interface right this time. Nathan Myers ncm@cantrip.org