Subject: Re: [boost] [thread] Can Boost.Thread use Boost.Atomic without falling on a compatibility issue?
From: Vicente J. Botet Escriba (vicente.botet_at_[hidden])
Date: 2013-01-13 12:12:35
Le 13/01/13 16:16, Andrey Semashev a écrit :
>
> once_flag must always be statically initialized, that's the key feature that
> allows call_once to be thread-safe. In C++03 this can only be guaranteed for
> POD types. C++11 also includes constant initialization into static
> initialization (i.e. when objects are initialized with constexpr
> constructors). All other objects are initialized during dynamic
> initialization, which is not thread-safe.
>
Thanks for clarifications, I understand your concern. The non-POD
once_flag implementation can not be used for static once_flag instances
in a thread safe mode.
Just for curiosity, from where comes the restriction that once_flag must
always be statically initialized? Could you point me to the standard?
Best,
Vicente